Lewden Electrical Palazzoli ATEX Solutions for Explosive Atmospheres - Industrial Plugs & Sockets, Enclosures, Cable Glands, Control Devices, Lighting Fixtures & Signalling Devices

ATEX
Solutions for explosive atmospheres
EDITION 2013

In 1904 PALAZZOLI began its activity in Brescia when electrical energy was first used in the industry.
The Company is specialized in manufacturing electrical appliances with safety features that are protected and watertight, for
industrial, marine, civil, agricultural and OEM applications. The offer of PALAZZOLI extends into a wide range of finished products,
to which special customized solutions are specifically developed in accordance to the needs of end-users.
The products conform to technical and safety standards and are manufactured with
very high quality materials, in metal and self-extinguishing isolated
thermosetting (GRP) and thermoplastic. PALAZZOLI undertakes
the commitment towards all end-users to offer reliable,
safe and lasting quality products. This task, as
in the last century of activity, continues
to honour the trust and respect
that customers have posted
in its trademark.
RESISTANCE, LONG LIFE AND RELIABILITY FOR
SUSTAINABLE PRODUCT DEVELOPMENT AND
APPLICATION
Since 1904

MADE IN PALAZZOLI
Palazzoli obtained from IMQ the certificate
IMQ 07 ATEXQ 001
guaranteeing that its ATEX equipments
can be used in hazardous areas for the
presence of gases, vapours, mists or dusts.
LEADING EXPERIENCE
AND KNOW-HOW IN
ELECTROTECHNOLOGY
HIGH QUALITY
PERFORMANCE OF
TECHNICAL SOLUTIONS

2
Solutions for each application requirement
Battery charging area
Painting department
Car parking

3
Dust and Gas
Heating plant
Carpentry
Large kitchen

4
Palazzoli ATEX products are designed and manufactured in order to avoid the risk of ignition.
Each item is approved and certified by TÜV SÜD in compliance with the Directive 94/9/EC
which guarantees the conformity for installation in hazardous areas. Each enclosure of
ATEX products, in compliance with EN 60079-0 standards, is tested as follows:
The technical characteristics of the products included in this catalogue, are defined after the
sequence of the above reported tests, in the indicated order and on the same sample piece.
1) Operating temperature
in order to determine the maximum service temperature of the
product.
2) Temperature Endurance Test
in climatic room at the maximum service temperature measured
with the previous test with 90% humidity for 4 weeks, and at the
minimum temperature -25° C ÷ -30° C for one day.
3) Impact test
tested at +10° C ÷ 15° C and -5° C ÷ 10° C of the maximum service
temperature.
4) IPXX protection degree test
(dust and water).
5) Tests on specific modes of protection
(pressure test, restricted breathing test, dielectric tests).
Tested Quality

5
Certified Quality
In compliance with the
Directive 94/9/CE of the European
Parliament dated 23rd
March 1994,
IMQ notified that Palazzoli
has a quality system of the
production according to the
Annex VII of the Directive.
Palazzoli products for Zone 1, 2, 21, 22
are approved by TÜV SÜD and have
IECEx certification.

6
Guaranteed quality and made in Italy
All the Palazzoli ATEX products are tested, not only with standard product tests, but also
with tests of the ATEX notified body, thus guaranteeing an increasead safety for the final
user.

7
Palazzoli range for ATEX zones
GAS DUST
ZONE 1 ZONE 2 ZONE 21 ZONE 22
POWERSUPPLY
Industrial plugs CEE-EX
Interlocked socket-outlets
in thermosetting (GRP)
TAIS-EX
Interlocked socket-outlets
in aluminium alloy
ALUPRES-EX
JUNCTION
Enclosures
TAIS-EX
Enclosures
in aluminium alloy
ALUPRES-EX
Cable glands and fittings UNI-EX
CONTROLLING-SIGNALLING
Rotary control devices
CAM-EX
Rotary control devices
in aluminium alloy
CAM-EX
Sirens and bells
in aluminium alloy
ALARM-EX
Small control devices
TAIS MIGNON-EX
Small control devices
in aluminium alloy
RONDO’-EX
LIGHTING
Lighting fixtures
aluminium alloy
RINO-EX
Lighting fixtures
in stainless steel
RINO-EX

8
PLUGS AND INTERLOCKED SOCKET-OUTLETS
ENCLOSURES AND CABLE GLANDS
CONTROL AND SIGNALLING DEVICES
INTERLOCKED SOCKET-OUTLETS
IN THERMOSETTING (GRP) 12
IN ALUMINIUM ALLOY 16
ROTARY CONTROL DEVICES
ENCLOSURES
CABLE GLANDS AND FITTINGS 26
SIRENS AND BELLS
FOR ALARM AND SIGNALLLING 34
INDUSTRIAL PLUGS 10

9
SMALL CONTROL DEVICES
PALAZZOLI ACADEMY
LIGHTING DEVICES
LIGHTING FIXTURES IN ALUMINIUM ALLOY 40
ATEX - PLANNING AND
INSTALLATION 49
LIGHTING FIXTURES IN STAINLESS STEEL 42
SMALL CONTROL DEVICES AND ENCLOSURES
Planning
and Installation
ATEX
This book has been written using the homonym text of Eng.Mirko Martina, member of CT 31.
Special thanks to Eng. Maurizio D’Addato, Director of the National Fire-watchers’ Corps, for
his kind permission to access the unique official statistical data that analyze the extent of
the damages suffered by people due to explosions.

10
Low voltage watertight straight plugs, IEC EN 60309-1
and IEC EN 60309-2 standard, suitable for applications
in areas at risk of explosive atmospheres as defined in
ATEX Directive 94/9/EC. The body of the plug is made
of very thick anti-static technopolymer in RAL 9005
black colour.
The contact holder insert is in self-extinguishing
technopolymer for versions up to 32A and in
thermosetting (GRP) material for the 63A version.
The plugs feature IP66 protection rating.
CONFORMITY TO STANDARDS
ATEX Directive 94/9/EC
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
Directive 2006/95/EC
EN 60309-1:1999 + A1:2007
EN 60309-2:1999 + A1:2007 + A2:2012
ATEX PROTECTION TYPE
II 3G Ex nA IIC TX Gc
II 2D Ex tb IIIC T XX °C Db IP66
Certificates can be downloaded from the website
www.palazzoli.com
PRODUCT SPECIFICATIONS
Body material:
Anti-static high thickness technopolymer
Surface resistivity
(prevention of electrostatic charge deposit):
<109
Colour:
RAL 9005 (black)
Contact holder insert material:
Self-extinguishing technopolymer (versions up to 32A)
Thermosetting - GRP (63A version)
Glow wire (IEC EN 60695):
850°C
960°C (contact holder insert - 63A version)
Self-extinguishing grade (UL94):
V2
Operating temperature:
-20°C ÷ +40°C
Protection rating:
IP66
Frequency:
50-60Hz
Cable specifications:
Low voltage industrial plugs
Zone 2, 21, 22
CEE-EX Series
Rated
current
(A)
Poles
Ø External
(mm)
Section
(mm2
)
16
2P+Q 8 - 13
1 - 2,53P+Q 8,5 - 14
3P+N+Q 10 - 15,5
32
2P+Q 11,5 - 17,5
2,5 - 63P+Q 12,5 - 19,5
3P+N+Q 14 - 21,5
63
2P+Q 17 - 26
4 - 103P+Q 19 - 28,5
3P+N+Q 21 - 31,5
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
℧

11
SUITABLE FOR ZONE 2 (GAS) AND 21-22 (DUST)
CEE-EX SERIES
Low voltage
watertight straight plugs
50-60Hz IP66
CEE-EX SERIES
Low voltage
watertight straight plugs
50-60Hz IP66
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
110 ˜ 2P+Q 4 477203EX 1
110 ˜ 3P+Q 4 477213EX 1
110 ˜ 3P+N+Q 4 477223EX 1
230 ˜ 2P+Q 6 477303EX 1
230 ˜ 3P+Q 9 477313EX 1
230 ˜ 3P+N+Q 9 477323EX 1
400 ˜ 2P+Q 9 477403EX 1
400 ˜ 3P+Q 6 477413EX 1
400 ˜ 3P+N+Q 6 477423EX 1
500 ˜ 3P+Q 7 477513EX 1
500 ˜ 3P+N+Q 7 477523EX 1
32
110 ˜ 3P+Q 4 477216EX 1
110 ˜ 3P+N+Q 4 477226EX 1
230 ˜ 2P+Q 6 477306EX 1
230 ˜ 3P+Q 9 477316EX 1
400 ˜ 3P+Q 6 477416EX 1
400 ˜ 3P+N+Q 6 477426EX 1
500 ˜ 3P+Q 7 477516EX 1
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
63
230 ˜ 3P+Q 9 477317EX 1
400 ˜ 3P+Q 6 477417EX 1
400 ˜ 3P+N+Q 6 477427EX 1
500 ˜ 3P+Q 7 477517EX 1
Characteristics:
Nickel-plated pins in one single unit, contact holder insert in
thermosetting (GRP) with GWT 960°C.
Dimensions
page46
PLUGS AND INTERLOCKED
SOCKET-OUTLETS

12
Wall-mounted watertight interlocked socket-outlets in
anti-static thermosetting (GRP) suitable for applications
in areas at risk of explosive atmospheres as defined in
ATEX Directive 94/9/EC.
The cover is attached to the back box by means of
stainless steel screws, the sealing is guaranteed by a
gasket in non-ageing elastomer that allows to keep the
IP66 protection rating.
The interlock system is made of metal, and the inside
isolator switch is an AC23A-AC3 class switch at rated
current with the capacity of withstanding a short circuit
≥ 10kA.
WALL-MOUNTED INTERLOCKED
SOCKET-OUTLETS IN THERMOSETTING (GRP)
Zone 2, 21, 22
TAIS-EX Series
Body material:
Anti-static thermosetting (GRP)
Surface resistivity
< 109
Colour:
RAL 9005 (black)
Glow wire (IEC EN 60695):
960°C
V0
-20°C ÷ +40°C
Protection rating:
IP66
Insulation class:
II e
Conditional short-circuit current - isolator switch:
≥ 10kA
Frequency:
50-60Hz
Rated operating current - isolator switch:
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
Rated current
(A)
Ø External
(mm)
Section
(mm2
)
16 12 - 18 1 - 10
20 / 32 16 - 25 1 - 10
40 / 63 16 - 25 6 - 16
16A
20A
32A
40A
63A
Thermal current Ith A 16 32 63
AC21A A 16 32 63
AC22A A 16 32 63
AC23A A 16 32 63
AC23A
230V
kW
4,5 8,5 20
400V 7,5 15 34
500V 8,5 17 44
AC3
230V
kW
4,5 8,5 18
400V 7,5 15 31
500V 8,5 17 40
℧
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
EN 60309-1:1999 + A1:2007
EN 60309-2:1999 + A1:2007 + A2:2012
EN 60309-4:2007 + A1:2012
II 3G Ex nR IIC T5/T6 Gc
www.palazzoli.com

13
SOCKET-OUTLETS
SUITABLE FOR ZONE 21-22 (DUST)
TAIS-EX SERIES
Wall-mounted
interlocked socket-outlets with
fuse-holder base
in insulating modular enclosure
50-60Hz IP66
TAIS-EX SERIES
Wall-mounted
interlocked socket-outlets
with MCB
50-60Hz IP66
TAIS-EX SERIES
Wall-mounted
without protection
50-60Hz IP66
MODULE 125 MODULE 125
MODULE 125
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
110 ˜ 2P+Q 4 463124EX 1
110 ˜ 3P+Q 4 463134EX 1
110 ˜ 3P+N+Q 4 463144EX 1
230 ˜ 2P+Q 6 463126EX 1
230 ˜ 3P+Q 9 463139EX 1
230 ˜ 3P+N+Q 9 463149EX 1
400 ˜ 2P+Q 9 463129EX 1
400 ˜ 3P+Q 6 463136EX 1
400 ˜ 3P+N+Q 6 463146EX 1
500 ˜ 3P+Q 7 463137EX 1
500 ˜ 3P+N+Q 7 463147EX 1
32
entry
M32
110 ˜ 3P+Q 4 472711EX 1
110 ˜ 3P+N+Q 4 472811EX 1
230 ˜ 2P+Q 6 472621EX 1
230 ˜ 3P+Q 9 472721EX 1
400 ˜ 3P+Q 6 472731EX 1
400 ˜ 3P+N+Q 6 472831EX 1
500 ˜ 3P+Q 7 472751EX 1
63
entry
M32
230 ˜ 3P+Q 9 472722EX 1
400 ˜ 3P+Q 6 472732EX 1
400 ˜ 3P+N+Q 6 472832EX 1
500 ˜ 3P+Q 7 472752EX 1
Equipment:
Insulated cable gland.
Characteristics:
10,3x38 cylindrical fuses for 16A socket-outlets.
14x51 cylindrical fuses for 32A socket-outlets.
DIII fuses for 63A socket-outlets.
Some equipments are double-marked and can be used in zone 2
(GAS) as shown in the table at page 14.
Complementary items:
Enclosures for compositions at page 15.
Thermosetting (GRP) backplate at page 15.
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
110 ˜ 2P+Q 4 464210EX 1
110 ˜ 3P+Q 4 464310EX 1
110 ˜ 3P+N+Q 4 464410EX 1
230 ˜ 2P+Q 6 464220EX 1
230 ˜ 3P+Q 9 464320EX 1
230 ˜ 3P+N+Q 9 464420EX 1
400 ˜ 2P+Q 9 464230EX 1
400 ˜ 3P+Q 6 464330EX 1
400 ˜ 3P+N+Q 6 464430EX 1
32
entry
M32
110 ˜ 3P+Q 4 464711EX 1
110 ˜ 3P+N+Q 4 464811EX 1
230 ˜ 2P+Q 6 464621EX 1
230 ˜ 3P+Q 9 464721EX 1
400 ˜ 3P+Q 6 464731EX 1
400 ˜ 3P+N+Q 6 464831EX 1
63
entry
M32
230 ˜ 3P+Q 9 464722EX 1
400 ˜ 3P+Q 6 464732EX 1
400 ˜ 3P+N+Q 6 464832EX 1
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
230 ˜ 2P+Q 6 467126EX 1
400 ˜ 3P+Q 6 467136EX 1
400 ˜ 3P+N+Q 6 467146EX 1
32
entry
M32
230 ˜ 2P+Q 6 470226EX 1
400 ˜ 3P+Q 6 470236EX 1
400 ˜ 3P+N+Q 6 470246EX 1
63
entry
M32
400 ˜ 3P+Q 6 470336EX 1
400 ˜ 3P+N+Q 6 470346EX 1
Equipment:
Characteristics:
Some equipments are double-marked and can be used in zone 2 (GAS)
as shown in the table at page 14.
Lamp indicating presence of voltage (on the socket-outlets with MCB).
Dimensions
page44

14
SUITABLE FOR ZONE 2 (GAS)
TAIS-EX SERIES
Wall-mounted
with fuse-holder base
50-60Hz IP66
TAIS-EX SERIES
Wall-mounted
with MCB
50-60Hz IP66
TAIS-EX SERIES
Wall-mounted
without protection
50-60Hz IP66
MODULE 125
Rated current
Socket-outlets
with fuse-holder
Socket-outlets
with MCB
Socket-outlets
without protection
Plug
16A 16A 16A 16A
20A 32A 32A 32A
40A 40A 63A 63A
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
110 ˜ 2P+Q 4 463124EX 1
110 ˜ 3P+Q 4 463134EX 1
110 ˜ 3P+N+Q 4 463144EX 1
230 ˜ 2P+Q 6 463126EX 1
230 ˜ 3P+Q 9 463139EX 1
230 ˜ 3P+N+Q 9 463149EX 1
400 ˜ 2P+Q 9 463129EX 1
400 ˜ 3P+Q 6 463136EX 1
400 ˜ 3P+N+Q 6 463146EX 1
500 ˜ 3P+Q 7 463137EX 1
500 ˜ 3P+N+Q 7 463147EX 1
20
entry
M32
110 ˜ 3P+Q 4 472711EX 1
110 ˜ 3P+N+Q 4 472811EX 1
230 ˜ 2P+Q 6 472621EX 1
230 ˜ 3P+Q 9 472721EX 1
400 ˜ 3P+Q 6 472731EX 1
400 ˜ 3P+N+Q 6 472831EX 1
500 ˜ 3P+Q 7 472751EX 1
40
entry
M32
230 ˜ 3P+Q 9 463339EX 1
400 ˜ 3P+Q 6 463336EX 1
400 ˜ 3P+N+Q 6 463346EX 1
500 ˜ 3P+Q 7 463337EX 1
Equipment:
Characteristics:
14x51 cylindrical fuses for 20A and 40A socket-outlets.
The products can be installed stand-alone, they cannot be
combined in compositions.
Some equipments are double-marked and can be used in zone 21-22
(Dust) as shown in the table at page 13.
Compatibility of plugs with interlocked socket-outlets for zone 2 (GAS)
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
110 ˜ 2P+Q 4 464210EX 1
110 ˜ 3P+Q 4 464310EX 1
110 ˜ 3P+N+Q 4 464410EX 1
230 ˜ 2P+Q 6 464220EX 1
230 ˜ 3P+Q 9 464320EX 1
230 ˜ 3P+N+Q 9 464420EX 1
400 ˜ 2P+Q 9 464230EX 1
400 ˜ 3P+Q 6 464330EX 1
400 ˜ 3P+N+Q 6 464430EX 1
32
entry
M32
110 ˜ 3P+Q 4 464711EX 1
110 ˜ 3P+N+Q 4 464811EX 1
230 ˜ 2P+Q 6 464621EX 1
230 ˜ 3P+Q 9 464721EX 1
400 ˜ 3P+Q 6 464731EX 1
400 ˜ 3P+N+Q 6 464831EX 1
40
entry
M32
230 ˜ 3P+Q 9 464339EX 1
400 ˜ 3P+Q 6 464336EX 1
400 ˜ 3P+N+Q 6 464346EX 1
Equipment:
Insulated cable gland, lamp indicating presence of voltage.
Characteristics:
The products can be installed stand-alone, they cannot be combined in
compositions. Some equipments are double-marked and can be used in
zone 21-22 (DUST) as shown in the table at page 13.
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
230 ˜ 2P+Q 6 467126EX 1
400 ˜ 3P+Q 6 467136EX 1
400 ˜ 3P+N+Q 6 467146EX 1
32
entry
M32
230 ˜ 2P+Q 6 470226EX 1
400 ˜ 3P+Q 6 470236EX 1
400 ˜ 3P+N+Q 6 470246EX 1
63
entry
M32
400 ˜ 3P+Q 6 470336EX 1
400 ˜ 3P+N+Q 6 470346EX 1
Equipment:

15
SOCKET-OUTLETS
TAIS-EX SERIES
Watertight enclosures
with blind cover
IP66
TAIS SERIES
Back plate in thermosetting
(GRP) with guided system
for the composition of
distribution boards with
socket-outlets and enclosures
UNI SERIES
Fittings for
enclosure/socket coupling
TAIS SERIES
Cup shaped milling cutters
equipped with quick special
steel drill connection with
tungsten carbide gear teeth
specific for thermosetting (GRP)
CEE-EX SERIES
Devices for
restricted breathing testing
of the interlocked socket-outlets
External
dimensions
(mm)
Maximum power
dissipation allowed
(W)
Holes
Installable
devices
Palazzoli
code
Pack
Q.ty
125x185x125 17 blind 1 532200EX 1
250x185x125 25 blind 2 532202EX 1
380x185x125 35 blind 3 532204EX* 1
Characteristics:
Supplied with drilling template.
The protection rating and the consequent certification of the distribution
board are guaranteed if the holes are drilled with the proper set of cup
shaped milling cutters code 538410 (TAIS series) as per the instructions
supplied with the product.
* The product 532204EX can be used only in zone 21, 22.
Internal mounting plates in steel at page 21.
External
dimensions
(mm)
Installable
devices
Palazzoli
code
Pack
Q.ty
125x630 1 538800 1
250x630 2 538802 1
380x630 3 538804 1
Equipment:
Built-in threaded brass dowels, supplied with screws and relative
stainless steel washers for fastenings.
Characteristics:
The guided positioning system simplify the assembling of the
equipments on the back plate.
From hole To hole
Palazzoli
code
Pack
Q.ty
M25/Pg21 M25 538421 1
M32/Pg29 M32 538429 1
Characteristics:
They are used to couple socket-outlets with enclosures.
Holes Nominal diameter
(mm)
Palazzoli
code
Pack
Q.ty
M20 - M25 - M32 - M40 20,5 - 25,5 - 32,5 - 40,5 538410 1
Interlocked
socket-outlets
rated current
Poles
Palazzoli
code
Pack
Q.ty
16A
2P+Q 478126 1
3P+Q 478136 1
3P+N+Q 478146 1
20A/32A
2P+Q/3P+Q 478206 1
3P+N+Q 478246 1
40A/63A 2P+Q/3P+Q/3P+N+Q 478306 1
Equipment:
Transparent tube to be applied at the testing device.
Instructions:
Insert the testing device into the socket-outlet (test port), tighten the
device’s shade ring and do the testing according to Art.33.7.1 of
EN60079-15 Standards with the suitable measuring device.
Composing guide for ATEX socket-outlets combinations
WARNING: The protection rating and the consequent certification of
the distribution board are guaranteed if the holes are drilled with the
proper set of cup shaped milling cutters code 538410 (TAIS series) as
per the instructions supplied with the product. The composition with
three socket-outlets can be used in Zone 21, 22 only.
532200EX
538800
M125 M125 M125 M125 M125 M125
532202EX
538802
532204EX
538804
Dimensions
page44

16
Wall-mounted interlocked socket-outlets in aluminium
alloy EN1076 AC46001DF suitable for applications in
areas at risk of explosive atmospheres as defined in
Back box and cover are treated with ecological
anticorrosion passivation with fluoro-zirconium and
finished with hot polymerized scratch-resistant non-
toxic polyester painting. The colour is RAL 9005
black. The interlock system is made of metal, and the
inside isolator switch is an AC23A-AC3 class switch
at rated current with the capacity of withstanding a
short circuit ≥ 10kA. The cover is attached to the back
box by means of stainless steel screws, the sealing
is guaranteed by a gasket in non-ageing elastomer.
Supplied with flange with insulated cable gland.
Material:
Aluminium alloy EN1076 AC46001DF
Treatment of passivation with fluoro-zirconium
Hot polymerized non-toxic polyester painting
Colour:
RAL 9005 (black)
-20°C ÷ +40°C
Protection rating:
IP66
Insulation class:
I
Conditional short-circuit current - isolator switch:
≥ 10kA
Frequency:
50-60Hz
Rated operating current - isolator switch:
WALL-MOUNTED INTERLOCKED
SOCKET-OUTLETS IN ALUMINIUM ALLOY
Zone 2, 21, 22
ALUPRES-EX Series
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
Rated current
(A)
Ø External
(mm)
Section
(mm2
)
16 12 - 18 1 - 10
25/32 16 - 25 1 - 10
40/63 16 - 25 6 - 16
16A
25A
32A
40A
63A
Thermal current Ith A 16 32 63
AC21A A 16 32 63
AC22A A 16 32 63
AC23A A 16 32 63
AC23A
230V
kW
4,5 8,5 20
400V 7,5 15 34
500V 8,5 17 44
AC3
230V
kW
4,5 8,5 18
400V 7,5 15 31
500V 8,5 17 40
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
EN 60309-1:1999 + A1:2007
EN 60309-2:1999 + A1:2007 + A2:2012
EN 60309-4:2007 + A1:2012
II 3G Ex nR IIC T5/T6 Gc
www.palazzoli.com

17
ALUPRES-EX SERIES
Wall-mounted
in modular enclosure
in aluminium alloy
50-60Hz IP66
ALUPRES-EX SERIES
Wall-mounted
without protection
in aluminium alloy
50-60Hz IP66
SOCKET-OUTLETS
SUITABLE FOR ZONE 21-22 (DUST)
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
110 ˜ 2P+Q 4 465124EX 1
110 ˜ 3P+Q 4 465134EX 1
110 ˜ 3P+N+Q 4 465144EX 1
230 ˜ 2P+Q 6 465126EX 1
230 ˜ 3P+Q 9 465139EX 1
230 ˜ 3P+N+Q 9 465149EX 1
400 ˜ 2P+Q 9 465129EX 1
400 ˜ 3P+Q 6 465136EX 1
400 ˜ 3P+N+Q 6 465146EX 1
500 ˜ 3P+Q 7 465137EX 1
500 ˜ 3P+N+Q 7 465147EX 1
32
entry
M32
110 ˜ 3P+Q 4 472246EX 1
110 ˜ 3P+N+Q 4 472256EX 1
230 ˜ 2P+Q 6 472336EX 1
230 ˜ 3P+Q 9 472346EX 1
400 ˜ 3P+Q 6 472446EX 1
400 ˜ 3P+N+Q 6 472456EX 1
500 ˜ 3P+Q 7 472546EX 1
63
entry
M32
230 ˜ 3P+Q 9 472347EX 1
400 ˜ 3P+Q 6 472447EX 1
400 ˜ 3P+N+Q 6 472457EX 1
500 ˜ 3P+Q 7 472547EX 1
Equipment:
Flange F1 with insulated cable gland on the top side.
Steel blind flange on the bottom side.
Characteristics:
14x51 cylindrical fuses for 32A socket-outlets.
DIII fuses for 63A socket-outlets.
Closing flanges at page 19.
Steel backplate at page 19.
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
230 ˜ 2P+Q 6 466126EX 1
400 ˜ 3P+Q 6 466136EX 1
400 ˜ 3P+N+Q 6 466146EX 1
32
entry
M32
230 ˜ 2P+Q 6 460226EX 1
400 ˜ 3P+Q 6 460236EX 1
400 ˜ 3P+N+Q 6 460246EX 1
63
entry
M32
400 ˜ 3P+Q 6 460336EX 1
400 ˜ 3P+N+Q 6 460346EX 1
Equipment:
Characteristics:
Dimensions
page44

18
ALUPRES-EX SERIES
Wall-mounted
in aluminium alloy
50-60Hz IP66
ALUPRES-EX SERIES
Wall-mounted
without protection
in aluminium alloy
50-60Hz IP66
SUITABLE FOR ZONE 2 (GAS)
Rated current
Socket-outlets
with fuse-holder
Socket-outlets
without protection
Plugs
16A 16A 16A
25A 32A 32A
40A 63A 63A
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
110 ˜ 2P+Q 4 465124EX 1
110 ˜ 3P+Q 4 465134EX 1
110 ˜ 3P+N+Q 4 465144EX 1
230 ˜ 2P+Q 6 465126EX 1
230 ˜ 3P+Q 9 465139EX 1
230 ˜ 3P+N+Q 9 465149EX 1
400 ˜ 2P+Q 9 465129EX 1
400 ˜ 3P+Q 6 465136EX 1
400 ˜ 3P+N+Q 6 465146EX 1
500 ˜ 3P+Q 7 465137EX 1
500 ˜ 3P+N+Q 7 465147EX 1
25
entry
M32
110 ˜ 3P+Q 4 472246EX 1
110 ˜ 3P+N+Q 4 472256EX 1
230 ˜ 2P+Q 6 472336EX 1
230 ˜ 3P+Q 9 472346EX 1
400 ˜ 3P+Q 6 472446EX 1
400 ˜ 3P+N+Q 6 472456EX 1
500 ˜ 3P+Q 7 472546EX 1
40
entry
M32
230 ˜ 3P+Q 9 465339EX 1
400 ˜ 3P+Q 6 465336EX 1
400 ˜ 3P+N+Q 6 465346EX 1
500 ˜ 3P+Q 7 465337EX 1
Equipment:
Characteristics:
14x51 cylindrical fuses for 25A and 40A socket-outlets.
The products can be installed stand-alone, they cannot be combined in
compositions.
Some equipments are double-marked and can be used in zone 21-22
(DUST) as shown in the table at page 17.
Compatibility of plugs with interlocked socket-outlets for zone 2 (GAS)
Rated
current
(A)
Rated
voltage
(V)
Voltage
colour
Poles
h
ref.
Palazzoli
code
Pack
Q.ty
16
entry
M25
230 ˜ 2P+Q 6 466126EX 1
400 ˜ 3P+Q 6 466136EX 1
400 ˜ 3P+N+Q 6 466146EX 1
32
entry
M32
230 ˜ 2P+Q 6 460226EX 1
400 ˜ 3P+Q 6 460236EX 1
400 ˜ 3P+N+Q 6 460246EX 1
63
entry
M32
400 ˜ 3P+Q 6 460336EX 1
400 ˜ 3P+N+Q 6 460346EX 1
Equipment:
Characteristics:
The equipments are double-marked and can be used in zone 21-22
(DUST) as shown in the table at page 17.

19
SOCKET-OUTLETS
ALUPRES-EX SERIES
Watertight enclosures
in aluminium alloy
with blind cover
IP66
ALUPRES SERIES
Back plate in painted
zinc-plated steel for the
composition of distribution
boards with socket-outlets
and enclosures
ALUPRES SERIES
Flanges F1 with metric thread
for socket-outlets and
enclosures with windowed walls
IP66
ALUPRES SERIES
Closing flanges F1
for socket-outlets and
IP66
Dimensions
page44
External
dimensions
(mm)
Maximum power
dissipation allowed
(W)
Windows
Palazzoli
code
Pack
Q.ty
125x125 10 511914EX 1
252x125 20 511919EX 1
Equipment:
N. 2 closing flanges.
Mounting plate in tropicalized steel.
Screws for internal and external earth connection.
External
dimensions
(mm)
Installable
devices
Palazzoli
code
Pack
Q.ty
250x558 2 532836 1
Material
Projection
(mm)
Threading
Palazzoli
code
Pack
Q.ty
Steel 18 M25 541055 1
Steel 51 M32 540180 1
Cable glands at page 28.
Material
Projection
(mm)
Palazzoli
code
Pack
Q.ty
Steel 6 540031 5
Thermoplastic 5,5 540091 5
Steel 32 540061 1
Cable glands at page 28.
Distribution board with two ATEX socket-outlets
511919EX
532836
M125 M125
CEE-EX SERIES
Devices for
restricted breathing testing
of the interlocked socket-outlets
Interlocked
socket-outlets
rated current
Poles
Palazzoli
code
Pack
Q.ty
16A
2P+Q 478126 1
3P+Q 478136 1
3P+N+Q 478146 1
20A/32A
2P+Q/3P+Q 478206 1
3P+N+Q 478246 1
40A/63A 2P+Q/3P+Q/3P+N+Q 478306 1
Equipment:
Transparent tube to be applied at the testing device.
Instructions:
Insert the testing device into the socket-outlet (test port), tighten the
device’s shade ring and do the testing according to Art.33.7.1 of
EN60079-15 Standards with the suitable measuring device.
F1
F1 F1

20
Watertight modular enclosures in anti-static
thermosetting (GRP) suitable for applications in areas
at risk of explosive atmospheres as defined in ATEX
Directive 94/9/EC.
gasket in non-ageing elastomer.
The enclosures are predisposed for the installation of a
DIN EN 50022 rail for mounting composable terminals
or either of a backplate in anti-corrosion tropicalized
steel.
Material:
Surface resistivity
< 109
Colour:
RAL 9005 (black)
Glow wire (EN 60695):
960°C
V0
-20°C ÷ +40°C
Protection rating:
IP66
Insulation class:
II e
WATERTIGHT enclosures IN
THERMOSETTING (GRP)
Zone 1, 2, 21, 22
TAIS-EX Series
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X X
℧
EN 60079-0:2009
EN 60079-7:2007
EN 60079-31:2009
II 2G Ex e IIC T5/T6 Gb
www.palazzoli.com

21
SUITABLE FOR ZONE 1-2 (GAS) AND 21-22 (DUST)
TAIS-EX SERIES
Watertight modular enclosures
with rapid mounting of the
accessories
IP66
TAIS SERIES
Mounting plates
in anti-corrosion tropicalized
steel for watertight enclosures
of 15/10 mm
TAIS-EX SERIES
with low cover
IP66
TAIS-EX SERIES
with high cover
IP66
TAIS SERIES
Cup shaped milling cutters
equipped with quick special
steel drill connection with
tungsten carbide gear teeth
specific for thermosetting (GRP)
External
dimensions
(mm)
Maximum power
dissipation allowed
(W)
Palazzoli
code
Pack
Q.ty
125x185x125 18 532200EX 1
190x185x125 19 532201EX 1
250x185x125 23 532202EX 1
290x185x125 24 532203EX 1
380x185x125 25 532204EX 1
Equipment:
Drilling template.
External
dimensions
(mm)
Maximum power
dissipation allowed
(W)
Palazzoli
code
Pack
Q.ty
92x92x68 8 532035EX 1
125x92x68 10 532045EX 1
185x92x68 12 532055EX 1
125x125x100 13 532116EX 1
185x125x100 15 532117EX 1
250x125x100 20 532118EX 1
Equipment:
Drilling template.
External
dimensions
(mm)
Maximum power
dissipation allowed
(W)
Palazzoli
code
Pack
Q.ty
92x92x100 11 532005EX 1
125x92x100 11 532006EX 1
185x92x100 16 532015EX 1
125x125x125 15 532016EX 1
185x125x125 17 532017EX 1
250x125x125 22 532018EX 1
Equipment:
Drilling template.
External
dimensions
(mm)
Plate
dimensions
(mm)
Palazzoli
code
Pack
Q.ty
92x92 59x59 532705 1
125x92 92x58 532714 1
185x92 142x62 532715 1
125x125 86x86 532716 1
185x125 100x86 532717 1
250x125 175x86 532718 1
125x185 95x145 532700 1
190x185 160x145 532701 1
250x185 220x145 532702 1
290x185 260x145 532703 1
380x185 333x145 532704 1
Holes Nominal diameter
(mm)
Palazzoli
code
Pack
Q.ty
M20 - M25 - M32 - M40 20,5 - 25,5 - 32,5 - 40,5 538410 1

22
Watertight wall-mounting enclosures in aluminium alloy
EN1076 AC46001DF suitable for applications in areas
Directive 94/9/EC.
finished with hot polymerized scratch-resistant non-
toxic polyester painting. The colour is RAL 9005 black.
Predisposed for internal and external earth connection.
Material:
Colour:
RAL 9005 (black)
-20°C ÷ +40°C
Protection rating:
IP55 - IP66
Insulation class:
I
WATERTIGHT ENCLOSURES
IN ALUMINIUM ALLOY
Zone 1, 2, 21, 22
ALUPRES-EX Series
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X X
EN 60079-0:2009
EN 60079-7:2007
EN 60079-31:2009
II 2G Ex e IIC T5/T6 Gb
II 2D Ex tb IIIC T XX °C Db IPXX
www.palazzoli.com

23
SUITABLE FOR ZONE 1-2 (GAS) AND 21-22 (DUST) SUITABLE FOR ZONE 1-2 (GAS) AND 22 (DUST)
ALUPRES-EX SERIES
Wall-mounting enclosures
in aluminium alloy
with blind walls
IP66
ALUPRES-EX SERIES
in aluminium alloy
with blind-flanged walls
IP55
External
dimensions
(mm)
Maximum power
dissipation allowed
(W)
Palazzoli
code
Pack
Q.ty
92x92x77 10 511910EX 1
125x125x113 20 511913EX 1
155x155x73 30 150021EX 1
185x185x145 40 511920EX 1
252x185x145 42 511921EX 1
Equipment:
Supplied with internal mounting plate (except code 511910EX).
External
dimensions
(mm)
Maximum power
dissipation allowed
(W)
Windows
Palazzoli
code
Pack
Q.ty
125x92x77 12 511911EX 1
185x92x77 23 511912EX 1
252x125x113 40 511917EX 1
220x220x108 45 511922EX 1
252x252x197 65 511923EX 1
Equipment:
Supplied with internal mounting plate (except code 511911EX and
511912EX).
ALUPRES SERIES
Flanges with metric thread for
socket-outlets and
IP66
ALUPRES SERIES
Raised closing flanges in
aluminium alloy for enclosures
with windowed walls
IP66
For window Threading
Palazzoli
code
Pack
Q.ty
F0 M25x1,5 541050 1
F1 M25x1,5 541055 1
F1 M32x1,5 540180 1
F3 M40x1,5 540190 1
F5 M50x1,5 540195 1
For window
Projection
(mm)
Palazzoli
code
Pack
Q.ty
F1 32 540061 1
F3 50 540063 1
F5 80 540065 1
F0
F0
F0
F0
F1
F1
F5
F5
F3
F3
F3 F3

24
GUIDE TO REALIZING TERMINAL ENCLOSURES
Enclosures of TAIS-EX in thermosetting and ALUPRES-EX in
aluminium alloy can be completed with cable glands and terminals,
to realize customized terminal enclosures, suitable to be installed in
zone 1,2, 21 and 22, in compliance with the ATEX Directive 94/9/EC.
To realize this configuration there are 2 methods:
Certified configurations: they can be obtained by the installer
himself, following the instructions indicated in the following guide;
Special configurations: they can be realized by Palazzoli on
customer specifications.
To realize this configuration you need to know:
a) number and type of the composable terminals;
b) number, type and dispositions of the cable glands.
For special configurations, you need to know also the cable type and the maximum rated current.
a) Number and type of the composable terminals
The EN50022 rail inside the enclosure can be completed with ATEX composable terminals in compliance with the IEC EN
60947-7-1 standards. In the table below, there are indicated the maximum number of composable terminals which can be
inserted inside the enclosures, according to the correct power dissipation prescribed by the standards and the maximum number
that can be physically inserted.
Palazzoli enclosures T6 class - Operating temperature 40°C
CODE
DIMENSIONS
(BxHxD)
MAXIMUM NUMBER OF COMPOSABLE TERMINALS
Certified configurations Maximum configuration allowed
2,5 mm² 4 mm² 6 mm² 10 mm² 16 mm² 35 mm² 2,5 mm² 4 mm² 6 mm² 10 mm² 16 mm² 35 mm²
532200EX 185x125x125 7 6 5 4 3 - 17 15 12 9 8 6
532201EX 190x185x125 7 6 5 4 3 - 28 25 19 15 13 10
532202EX 250x185x125 8 7 6 6 4 - 40 35 27 22 18 14
532203EX 290x185x125 8 7 6 5 4 - 47 42 32 25 21 16
532204EX 380x185x125 7 6 5 4 3 - 56 50 38 30 26 20
532035EX 92x92x68 4 3 3 - - - 11 10 8 6 5 4
532045EX 125x92x68 5 4 3 - - - 17 15 12 9 8 6
532055EX 185x92x68 5 4 4 3 - - 28 25 19 15 13 10
532116EX 125x125x100 6 5 4 3 - - 17 15 12 9 8 6
532117EX 185x125x100 6 5 4 3 3 - 28 25 19 15 13 10
532118EX 250x125x100 8 6 5 4 3 - 40 35 27 22 18 14
532005EX 92x92x100 6 5 4 4 - - 11 10 8 6 5 4
532006EX 125x92x100 5 4 4 3 - - 17 15 12 9 8 6
532015EX 185x92x100 7 6 5 4 3 - 28 25 19 15 13 10
532016EX 125x125x125 7 6 5 4 3 - 17 15 12 9 8 6
532017EX 185x125x125 7 6 5 4 3 - 28 25 19 15 13 10
532018EX 250x125x125 8 7 6 5 4 - 40 35 27 22 18 14
511910EX 92x92x77 5 4 3 3 - - 11 10 8 6 5 4
511913EX 125x125x113 9 8 6 5 4 - 17 15 12 9 8 6
150021EX 155x155x73 14 11 9 7 6 4 23 20 15 12 10 8
511920EX 185x185x145 14 13 11 9 7 5 28 25 19 15 13 10
511921EX 252x185x145 15 12 11 9 7 5 40 35 27 22 18 14
511911EX 125x92x77 6 5 4 3 - - 17 15 12 12 8 6
511912EX 185x92x77 11 9 7 6 4 - 28 25 19 15 13 10
511917EX 252x125x113 15 13 11 9 7 5 40 35 27 22 18 14
511922EX 220x220x108 16 14 12 9 8 5 35 31 23 19 16 12
511923EX 252x252x197 21 17 15 12 10 7 40 35 27 22 18 14
Certified configurations: they can be obtained at the maximum rated current of the terminals, considering only one section. These
configurations can be realized and certified by the installer, following the instructions supplied with the product.
Maximum configuration allowed: they can be realized with circuits with lower current than the maximum allowed by the terminals. For the
realization and certification of these enclosures, you need to contact Palazzoli.
The enclosure dimensions depends on the power dissipation of the devices inside the enclosure.
Terminals
Cable glands

25
b) Number, type and dispositions of the cable glands
Each enclosure can be drilled on the 4 sides with a maximum number of entries that depends on the hole diameter and the
side length and depth.
On TAIS-EX thermosetting enclosures it is necessary to drill through holes and use cable glands with long thread and the relative
nut. The holes must be drilled with specific tools for the thermosetting, such as the cup shaped milling cutters equipped with
quick special steel drill connection with tungsten carbide gear teeth code 538410, in order to avoid splinters and irrregularities
on the hole profile.
On ALUPRES-EX aluminium alloy enclosures it is possible to predispose the threading to directly screw the cable gland. On the
sides with free window, you must use flanges predisposed for the threading passage or the blind ones to be drilled.
In the table below, there are indicated the sides of the enclosure with free window and opening type.
CODE
DIMENSIONS
(BxHxD)
MAXIMUM NUMBER OF CABLE GLANDS THAT CAN BE INSTALLED ON EACH SIDE
LONG SIDE OF THE ENCLOSURE (B) SHORT SIDE OF THE ENCLOSURE (H)
M16 M20 M25 M32 M40 M50 M16 M20 M25 M32 M40 M50
532200EX 185x125x125 8 6 3 2 2 - 4 3 2 1 1 -
532201EX 190x185x125 8 6 3 2 2 - 8 6 3 2 2 -
532202EX 250x185x125 14 12 5 4 3 - 8 6 3 2 2 -
532203EX 290x185x125 16 14 6 5 4 - 8 6 3 2 2 -
532204EX 380x185x125 24 22 9 7 6 - 8 6 3 2 2 -
532035EX 92x92x68 1 1 - - - - 1 1 - - - -
532045EX 125x92x68 3 3 2 - - - 1 1 - - - -
532055EX 185x92x68 4 4 2 - - - 1 1 - - - -
532116EX 125x125x100 4 3 2 1 1 - 4 3 2 1 1 -
532117EX 185x125x100 8 6 3 2 2 1 4 3 2 1 1 -
532118EX 250x125x100 14 12 6 4 3 - 4 3 2 1 1 -
532005EX 92x92x100 1 1 - - - - 1 1 - - - -
532006EX 125x92x100 3 3 2 - - - 1 1 - - - -
532015EX 185x92x100 4 4 2 - - - 1 1 - - - -
532016EX 125x125x125 5 4 2 1 - - 5 4 2 1 - -
532017EX 185x125x125 7 6 4 3 - - 5 4 2 1 - -
532018EX 250x125x125 10 8 5 4 - - 5 4 2 1 - -
511910EX 92x92x77 2 2 1 - - 2 2 1 - - -
511913EX 125x125x113 5 4 2 2 - - 5 4 2 2 - -
150021EX 155x155x73 6 5 3 1 - - 6 5 3 1 - -
511920EX 185x185x145 12 10 8 4 3 2 12 10 8 4 3 2
511921EX 252x185x145 16 14 10 5 4 3 12 10 8 4 3 2
511911EX 125x92x77 3 2 2 - - - - - F0 - - -
511912EX 185x92x77 4 3 2 - - - - - F0 - - -
511917EX 252x125x113 9 8 5 4 - - - - F1 F1 - -
511922EX 220x220x108 - - - - F3 - - - - - F3 -
511923EX 252x252x197 - - - - - F5 24 18 12 7 6 3
The above instructions are based on calculations of power dissipation relative to the maximum values prescribed by the
standards in force.
Giving precise information about the terminal boards compositions, cables, currents, cable glands disposition and types,
PALAZZOLI CAN REALIZE CUSTOMIZED SOLUTIONS, on request.

26
Cable glands in technopolymer and in nickeled brass
with neoprene gasket.
Adaptors in galvanised steel with male threading Pg or
Gas and female threading to connect devices of
different standards.
The products are suitable for applications in areas
Directive 94/9/EC.
Material:
(insulated cable glands)
Body in polyamide
Gasket in neoprene
(brass cable glands)
Body in nickeled brass
Gasket in neoprene
(adaptors)
Galvanised steel
Colour:
RAL 7035 grey (insulated Pg cable glands)
RAL 5012 black (insulated metric cable glands)
Protection rating:
IP66/IP68 (cable glands)
IP66/IP67 (adaptor)
(insulated cable glands)
-20°C ÷ +80°C (M12)
-35°C ÷ +95°C
(brass cable glands)
-40°C ÷ +100°C
(adaptors)
-40°C ÷ +150°C
CABLE GLANDS
Zone 1, 2, 21, 22
UNI-EX Series
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X X
EN 60079-0:2004
EN 60079-7:2003
EN 61241-0:2006
EN 61241-1:2004
(cable glands)
II 2 GD Ex e II, Ex tD A21 IP6X
(adaptors)
II 2 GD Ex d IIC, Ex e II, Ex tD A21
www.palazzoli.com

27
UNI-EX SERIES
Insulated cable glands
with Pg thread
IP66/IP68
UNI-EX SERIES
Insulated screwcaps
with Pg thread
IP66/IP67
UNI SERIES
Polygonal nuts with Pg thread
UNI-EX SERIES
with Pg thread
and long thread
IP66/IP68
Thread
Fixing hole
(mm)
Fastening
diameter
(mm)
Thread
length
(mm)
Palazzoli
code
Pack
Q.ty
Pg7 13 3-6,5 8 571007EX 100
Pg9 16 4-8 8 571009EX 100
Pg11 19 5-10 8 571011EX 100
Pg13,5 21 6,5-12 9 571013EX 100
Pg16 23 10-14 10 571016EX 50
Pg21 29 13-18 11 571021EX 50
Pg29 38 18-25 11 571029EX 25
Pg36 48 22-32 13 571036EX 10
Pg42 55 32-38 13 571042EX 5
Pg48 61 37-44 14 571048EX 5
Thread
Fixing hole
(mm)
Fastening
diameter
(mm)
Thread
length
(mm)
Palazzoli
code
Pack
Q.ty
Pg7 13 3-6,5 15 571107EX 100
Pg9 16 4-8 15 571109EX 100
Pg11 19 5-10 15 571111EX 100
Pg13,5 21 6,5-12 15 571113EX 100
Pg16 23 10-14 15 571116EX 50
Pg21 29 13-18 15 571121EX 50
Pg29 38 18-25 15 571129EX 25
Pg36 48 22-32 18 571136EX 10
Pg42 55 32-38 18 571142EX 5
Pg48 61 37-44 18 571148EX 5
Thread
Palazzoli
code
Pack
Q.ty
21 580232EX 1
29 580233EX 1
36 580234EX 1
Equipment:
With gasket included.
Thread
Palazzoli
code
Pack
Q.ty
Pg7 571207 50
Pg9 571209 50
Pg11 571211 50
Pg13,5 571213 50
Pg16 571216 50
Pg21 571221 25
Pg29 571229 20
Pg36 571236 10
Pg42 571242 5
Pg48 571248 5

28
UNI-EX SERIES
with metric thread
IP66/IP68
UNI-EX SERIES
with metric thread
and long thread
IP66/IP68
Thread
Fixing hole
(mm)
Fastening
diameter
(mm)
Thread
length
(mm)
Palazzoli
code
Pack
Q.ty
M12x1,5 12,5 4-6,5 8 581012EX 50
M16x1,5 16,5 5-10 10 581016EX 50
M20x1,5 20,5 10-14 10 581020EX 50
M25x1,5 25,5 12-18 10 581025EX 20
M32x1,5 32,5 16-25 10 581032EX 20
M40x1,5 40,5 22-32 10 581040EX 20
M50x1,5 50,5 28-38,5 12 581050EX 10
M63x1,5 63,5 40-48 12 581063EX 5
Thread
Fixing hole
(mm)
Fastening
diameter
(mm)
Thread
length
(mm)
Palazzoli
code
Pack
Q.ty
M12x1,5 12,5 4-6,5 15 581112EX 50
M16x1,5 16,5 5-10 15 581116EX 50
M20x1,5 20,5 10-14 15 581120EX 50
M25x1,5 25,5 12-18 15 581125EX 20
M32x1,5 32,5 16-25 15 581132EX 20
M40x1,5 40,5 22-32 16 581140EX 20
M50x1,5 50,5 28-38,5 16 581150EX 10
M63x1,5 63,5 40-48 16 581163EX 5
UNI SERIES
Insulated polygonal nuts
with metric thread
Thread
Palazzoli
code
Pack
Q.ty
M12x1,5 581212 50
M16x1,5 581216 50
M20x1,5 581220 50
M25x1,5 581225 50
M32x1,5 581232 50
M40x1,5 581240 20
M50x1,5 581250 10
M63x1,5 581263 5

29
UNI-EX SERIES
Brass cable glands
with metric thread
IP66/IP68
Thread
Fixing hole
(mm)
Fastening
diameter
(mm)
Thread
length
(mm)
Palazzoli
code
Pack
Q.ty
M12x1,5 12,5 4,5-6,5 15 582112EX 50
M16x1,5 16,5 5-9,5 15 582116EX 50
M20x1,5 20,5 8-13 15 582120EX 50
M25x1,5 25,5 9-16 15 582125EX 20
M32x1,5 32,5 12-21 15 582132EX 20
M40x1,5 40,5 16-27 15 582140EX 20
M50x1,5 50,5 23-35 15 582150EX 10
M63x1,5 63,5 36-48 15 582163EX 5
UNI SERIES
Brass polygonal nuts
with metric thread
Guide to choosing
Thread
Palazzoli
code
Pack
Q.ty
M12x1,5 582212 50
M16x1,5 582216 50
M20x1,5 582220 50
M25x1,5 582225 25
M32x1,5 582232 20
M40x1,5 582240 10
M50x1,5 582250 10
M63x1,5 582263 5
Male
thread
Female
thread
Palazzoli
code
Pack
Q.ty
3/8” Gas M16x1,5 580360EX 1
1/2” Gas M20x1,5 580361EX 1
3/4” Gas M25x1,5 580364EX 1
1” Gas M32x1,5 580365EX 1
Male
thread
Female
thread
Palazzoli
code
Pack
Q.ty
Pg21 M25x1,5 580394EX 1
Pg29 M32x1,5 580395EX 1
Pg36 M40x1,5 580396EX 1
Male thread
Female thread
UNI-EX SERIES
Adaptors in galvanised steel
for conduit/box couplings
Gas/Metric
IP66/IP67
UNI-EX SERIES
Adaptors in galvanised steel
for conduit/box couplings
Pg/Metric
IP66/IP67

30
Watertight control devices in anti-static thermosetting
(GRP) suitable for applications in areas at risk of
explosive atmospheres as defined in ATEX
Directive 94/9/EC.
gasket in non-ageing elastomer. Supplied with internal
earth terminal. The isolator switch is an AC23A-AC3
class switch at rated current with the capacity of
withstanding a short circuit ≥ 10kA, the mechanical
duration is over one million of operations.
WATERTIGHT CONTROL DEVICES
IN THERMOSETTING (GRP)
Zone 2, 21, 22
CAM-EX Series
Body material:
Surface resistivity
< 109
Colour:
RAL 9005 (black)
960°C
V0
-20°C ÷ +40°C
Protection rating:
IP66
Insulation class:
II e
Rated operating voltage (Ui):
500V
Conditional short-circuit current:
≥ 10kA
Mechanical duration:
1.000.000 operations
Rated operating current (Ie):
Connections:
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
10A
16A
20A
25A
32A
40A
50A
63A
Thermal current Ith A 16 25 40 63
AC21A
415V
A 16 25 40 63
500V
AC22A
415V
A 16 25 40 63
500V
AC23A
230V
A 16 25 40 63400V
500V
AC23A
230V
kW
4,5 7 11 20
400V 7,5 12 19 34
500V 10 14 23 44
AC3
230V
kW
4,5 7 11 18
400V 7,5 12 19 31
500V 10 14 23 40
Cable section mm2
1-4 1,5-6 4-10 6-16
Tightening torque Nm 1,5 1,5 2 2
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
EN 60947-3:2009 + A1:2012
II 3G Ex nR IIC T6 Gc
www.palazzoli.com
℧

31
CONTROL AND SIGNALLING
DEVICES
SUITABLE FOR ZONE 21-22 (DUST) SUITABLE FOR ZONE 2 (GAS)
Dimensions
page45
CAM-EX SERIES
Watertight wall-mounting
rotary switches
IP66
CAM-EX SERIES
rotary switches
IP66
Rated
current
(A)
Poles
Enclosure
dimensions
(mm)
Holes Palazzoli
code
Pack
Q.ty
16
2 92x125
K 292101EX 1
3 92x125
K 292102EX 1
4 92x125
K 292103EX 1
25
2 92x125
L 292201EX 1
3 92x125
L 292202EX 1
4 92x125
L 292203EX 1
40
2 125x185
M 292301EX 1
3 125x185
M 292302EX 1
4 125x185
M 292303EX 1
63
2 125x185
N 292411EX 1
3 125x185
N 292412EX 1
4 125x185
N 292413EX 1
Equipment:
Insulated cable glands.
Internal earth terminal.
Characteristics:
The same equipment can be used in zone 2 (GAS) as shown in the table
on the side.
Rated
current
(A)
Poles
Enclosure
dimensions
(mm)
Holes Palazzoli
code
Pack
Q.ty
10
2 92x125
K 292101EX 1
3 92x125
K 292102EX 1
4 92x125
K 292103EX 1
20
2 92x125
L 292201EX 1
3 92x125
L 292202EX 1
4 92x125
L 292203EX 1
32
2 125x185
M 292301EX 1
3 125x185
M 292302EX 1
4 125x185
M 292303EX 1
50
2 125x185
N 292411EX 1
3 125x185
N 292412EX 1
4 125x185
N 292413EX 1
Equipment:
Internal earth terminal.
Characteristics:
The same equipment can be used in zone 21,22 (DUST) as shown in the
table on the side.
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M25
M25
M25
M25
M32
M32
M25
M25
M25
M25
M32
M32
M32
M32
M25
M25
M25
M25
M25
M25
M25
M25
M25
M25
M32
M32
M40
M40
M32
M32
M40
M40
M32
M32
M40
M40

32
Watertight control devices in aluminium alloy EN1076
AC46001DF suitable for applications in areas at
risk of explosive atmospheres as defined in ATEX
Directive 94/9/EC.
finished with hot polymerized scratch-resistant
non-toxic polyester painting.
The isolator switch is an AC3-AC23A class switch at
rated current with the capacity of withstanding a short
circuit ≥ 10kA, the mechanical duration is over one
million of operations.
Zone 2, 21, 22
CAM-EX Series
Body material:
Colour:
RAL 9005 (black)
-20°C ÷ +40°C
Protection rating:
IP66
Rated operating voltage (Ui):
500V
Insulation class:
I
Conditional short-circuit current:
≥ 10kA
Mechanical duration:
1.000.000 operations
Rated operating current (Ie):
Connections:
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
16A 25A 32A
50A
63A
Thermal current Ith A 16 25 32 63
AC21A
415V
A 16 25 40 63
500V
AC22A
415V
A 16 25 40 63
500V
AC23A
230V
A 16 25 40 63400V
500V
AC23A
230V
kW
4,5 7 11 20
400V 7,5 12 19 34
500V 10 14 23 44
AC3
230V
kW
4,5 7 11 18
400V 7,5 12 19 31
500V 10 14 23 40
Cable section mm2
1-4 1,5-6 4-10 6-16
Tightening torque Nm 1,5 1,5 2 2
WATERTIGHT CONTROL DEVICES
IN ALUMINIUM ALLOY
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
EN 60947-3:2009 + A1:2012
II 2D Ex tb IIIC T 70 °C Db IP66
www.palazzoli.com

33
Dimensions
page45
DEVICES
CAM-EX SERIES
rotary switches
in aluminium alloy
IP66
CAM-EX SERIES
rotary selector switches
in aluminium alloy
IP66
Rated
current
(A)
Poles
Enclosure
dimensions
(mm)
Holes Palazzoli
code
Pack
Q.ty
16
2 92x92
Q 272141EX 1
3 92x92
Q 272142EX 1
4 92x92
Q 272143EX 1
6 92x125
Q 272144EX 1
25
2 92x92
Q 272241EX 1
3 92x92
Q 272242EX 1
4 92x92
Q 272243EX 1
6 92x125
Q 272244EX 1
40
2 125x125
C 272301EX 1
3 125x125
C 272302EX 1
4 125x125
C 272303EX 1
6 125x185
C 272304EX 1
63
Zone 21, 22
50
Zone 2
3 125x185
C 282402EX 1
4 125x185
C 282403EX 1
6 125x185
C 282404EX 1
Equipment:
Internal and external earth terminal.
Rated
current
(A)
Poles
Enclosure
dimensions
(mm)
Holes Palazzoli
code
Pack
Q.ty
16
3 92x125
V 272146EX 1
4 92x125
V 272147EX 1
25
3 92x125
W 272246EX 1
4 92x125
W 272247EX 1
40
3 125x185
V 272306EX 1
4 125x185
V 272307EX 1
50
3 125x185
W 282406EX 1
4 252x185
W 282407EX 1
Equipment:
M20
M20
M20
M20
M20
M20
M25
M25
M25
M25
M25
M25
M25
M25
M25
M25
M32
M32
M32
M32
M32
M32
M32
M32
M32
M32
M32
M32
M32
M32
M20
M20
M25
M25
M32
M32
M32
M32
2xM20
2xM20
2xM20
2xM20
2xM25
2xM25
2xM25
2xM25

34
Sirens and bells in aluminium alloy for continuous
operation, suitable for applications in areas at risk
of explosive atmospheres as defined in ATEX
Directive 94/9/EC.
The internal terminal board is in self-extinguishing
thermosetting insulating material. Screws for internal
and external earth connection. Back box and cover
are treated with ecological anti-corrosion passivation
with fluoro-zirconium and finished with hot polymerized
scratch-resistant non-toxic polyester painting. The
colour of the back box is RAL 9005 black while the
cover is RAL 2011 deep orange.
The gasket in non-ageing elastomer and the stainless
steel screws guarantee the watertight sealing with IP66
protection rating for the sirens and IP55 for the bells.
Zone 2, 21, 22
ALARM-EX Series
Body material:
Siren drum material:
Painted galvanised steel
Colour:
RAL 9005 (black)
RAL 2011 (deep orange)
-20°C ÷ +40°C
Protection rating:
IP66 (sirens)
IP55 (bells)
Operating current:
24VAC ÷ 230VAC
Insulation class:
I
Frequency:
50-60Hz
WATERTIGHT SIRENS AND BELLS FOR
ALARMS AND SIGNALLING
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
EN 62080:2009
(sirens)
II 3G Ex nA IIC T4/T3 Gc
(bells)
II 3G Ex nA IIC T4/T3 Gc
II 3D Ex tc IIIB T 70 °C Dc IP55
www.palazzoli.com

35
SUITABLE FOR ZONE 2 (GAS) AND 21-22 (DUST) SUITABLE FOR ZONE 2 (GAS) AND 22 (DUST)
ALARM-EX SERIES
Watertight sirens
in aluminium alloy
with vibrating diaphragm
50-60Hz IP66
ALARM-EX SERIES
Watertight bells
in aluminium alloy
with steel drum
50-60Hz IP55
Rated
current
(V)
Sound
level
(dB)
Initial
power
(VA)
Vibrating
power
(VA)
Palazzoli
code
Pack
Q.ty
24 105 60 25 900453EX 1
110 105 60 25 900463EX 1
230 105 60 25 900473EX 1
Equipment:
Insulated cable gland M20.
Terminal block in insulating thermosetting (GRP).
Rated
current
(V)
Sound
level
(dB)
Initial
power
(VA)
Vibrating
power
(VA)
Palazzoli
code
Pack
Q.ty
24 101 13 11 900253EX 1
110 101 13 11 900263EX 1
230 101 13 11 900273EX 1
Equipment:
Terminal block in insulating thermosetting (GRP).
ALARM-EX SERIES
Directional horn for sirens
Dimensions
page46
DEVICES
Diameter
max
(mm)
Projection
siren+horn
(mm)
Palazzoli
code
Pack
Q.ty
112 238 900449 1
Equipment:
Stainless steel fixing screws.

36
Small devices and watertight enclosures in anti-static
thermosetting (GRP) suitable for applications in areas
Directive 94/9/EC.
Zone 2, 21, 22
TAIS MIGNON-EX Series
Material:
Surface resistivity
< 109
Colour:
RAL 9005 (black)
960°C
V0
-20°C ÷ +40°C
Protection rating:
IP66
Insulation class:
II e
SMALL DEVICES AND ENCLOSURES
IN THERMOSETTING (GRP)
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
www.palazzoli.com
℧

37
TAIS MIGNON-EX SERIES
Switches in watertight
wall-mounting enclosure
IP66
Push buttons ON-OFF in
watertight wall-mounting
enclosure in thermosetting (GRP)
IP66
Selector switches in watertight
IP66
Push buttons in watertight
IP66
Dimensions
page46
Electrical
scheme
Poles Rated current Palazzoli
code
Pack
Q.ty
One-way 1 16A 250V~ / 10A 400V~ 202271EX 1
One-way 2 16A 250V~ / 10A 400V~ 202282EX 1
Two-way 1 16A 250V~ / 10A 400V~ 202276EX 1
Equipment:
Characteristics:
Predisposed for restricted breathing testing.
code
Pack
Q.ty
1 10A 400V~ 261433EX 1
Equipment:
Characteristics:
code
Pack
Q.ty
1 16A 250V~ / 10A 400V~ 202275EX 1
Equipment:
Characteristics:
Removing the internal jumper, the device can be used as two
indipendent one-pole switches.
code
Pack
Q.ty
1 NO 10A 400V~ 261435EX 1
1 NC 10A 400V~ 261445EX 1
Equipment:
Characteristics:
IP66
External
dimensions
(mm)
Holes Entries Palazzoli
code
Pack
Q.ty
62x80x38
õ M20 101021EX 12
62x80x38
ô M20 101031EX 10
62x80x38
ö M20 101041EX 12
62x80x38
® M20 101061EX 12
77x102x48
ò M20 101151EX 10
77x102x48
® M25 101161EX 1
77x102x55
_ M25 101181EX 12
Equipment:
Characteristics:
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M20
M25
M25
M25
M25
M25
M25
M25 M25

38
Small devices and watertight enclosures in aluminium
alloy EN1076 AC46001DF suitable for applications in
areas at risk of explosive atmospheres as defined in
finished with hot polymerized scratch-resistant non-toxic
polyester painting.
Zone 2, 21, 22
RONDÒ-EX Series
Body material:
Colour:
RAL 9005 (black)
-20°C ÷ +40°C
Protection rating:
IP66 (switches/push buttons)
IP65 (enclosures)
Insulation class:
I
sMaLL deviCes and enCLosures
in aLuMiniuM aLLoY
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
II 2D Ex tb IIIC T 70 °C Db IP6X
www.palazzoli.com

39
RONDÒ-EX SERIES
One-way switches
in wall-mounting enclosure
in aluminium alloy
IP66
RONDÒ-EX SERIES
Wall-mounting round
enclosures in aluminium alloy
with metric entries
IP65
Internal
diameter
(mm)
Maximum power
dissipation allowed
(W)
Entry
type
Palazzoli
code
Pack
Q.ty
62 3 1xM20 112020EX 1
62 3 2xM20 112030EX 1
62 3 3XM20 112040EX 1
82 4 1XM25 113020EX 1
82 4 2XM25 113030EX 1
82 4 3XM25 113040EX 1
Equipment:
Characteristic:
Poles Rated current
Entry
type
Palazzoli
code
Pack
Q.ty
1 16A 250V~ / 10A 400V~ M20 201156EX 1
Equipment:
Characteristic:
Poles Rated current
Entry
type
Palazzoli
code
Pack
Q.ty
1NO 10A 400V~ M20 261021EX 1
Equipment:
Characteristic:
Poles Rated current
Entry
type
Palazzoli
code
Pack
Q.ty
1 16A 250V~ / 10A 400V~ M20 201151EX 1
2 16A 250V~ / 10A 400V~ M20 201152EX 1
Equipment:
Characteristic:
RONDÒ-EX SERIES
Two-way switches
in aluminium alloy
IP66
RONDÒ-EX SERIES
Push-buttons
in aluminium alloy
IP66
Dimensions
page46

40
Watertight lighting fixture in aluminium alloy EN1076
AC46001DF suitable for applications in areas at
risk of explosive atmospheres as defined in ATEX
Directive 94/9/EC. The body of the lighting fixture is
treated with ecological anti-corrosion passivation with
fluoro-zirconium and finished with hot polymerized
scratch-resistant non-toxic polyester painting. The colour
of the body is RAL 7035 light grey.
The diffuser is in prismatic tempered glass. The protection
cage is RAL 2011 deep orange and is attached to the
body by means of stainless steel screws, the sealing is
guaranteed by a gasket in non-ageig elastomer.
Predisposed for entry through an M20 cable gland.
Complete with internal and external earth screw.
Zone 2, 21, 22
RINO-EX Series
Body material:
Diffuser material:
Prismatic tempered glass
Protection cage material:
Painted tropicalized steel wire
Colour:
RAL 7035 (light grey) - Back box
RAL 2011 (deep orange) - Protection cage
Protection rating:
IP65
Insulation class:
I
-20°C ÷ +40°C
Lampholder:
E27 type in porcelain
Rated voltage:
230V
Frequency:
50-60Hz
Cable section max:
2,5 mm2
WATERTIGHT LIGHTING FIXTURE
IN ALUMINIUM ALLOY
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
EN 60598-1:2008 + A11: 2009
EN 60598-2-1:1989
II 3G Ex nA IIC 145/160/190 °C (T3) Gc
II 2D Ex tb IIIC T 75/85/90 °C Db IP65
www.palazzoli.com

41
RINO-EX SERIES
Watertight oval lighting fixture
in aluminium alloy
with protection cage
230V 50-60Hz IP65
RINO-EX SERIES
Watertight round lighting fixture
in aluminium alloy
with protection cage
230V 50-60Hz IP65
Lamp max wattage
incandescent
(W)
Dimensions
(mm)
Palazzoli
code
Pack
Q.ty
60 199x112 831072EX 1
75 226x130 831172EX 1
100 295x170 831272EX 1
Equipment:
Internal and external earth screw.
Lamp max wattage
incandescent
(W)
Dimensions
(mm)
Palazzoli
code
Pack
Q.ty
75 200x182 830072EX 1
Equipment:
Internal and external earth screw.
Lamp/lighting fixture correspondence
Dimensions
Lamp/lighting fixture correspondence
Max wattage
Dimensions
page47
LIGHTING DEVICES
Lamp
type
Lighting
fixture type
Incand.
E27
Mixed light
E27
Electronic
compact
E27
60W 60W max 42W max 15W max
Lamp
type
Lighting
fixture type
A
(mm)
B
(mm)
60W 90 38
75W 110 40
100W 168 43
75W 90 38

42
Watertight lighting fixture in stainless steel AISI304
suitable for applications in areas at risk of explosive
atmospheres as defined in ATEX Directive 94/9/EC.
The diffuser is in tempered glass. The fixing hooks are
in stainless steel AISI304. The sealing is guaranteed by
a reinforced gasket in non-ageing elastomer.
Complete with corrosion resistant non-loosening
terminals and non-sparking lampholder.
Supplied with M20 cable gland. Complete with internal
and external earth connection.
Zone 2, 21, 22
RINO-EX Series
Enclosure material:
Stainless steel AISI304
Diffuser material:
Tempered glass
Protection rating:
IP66
Insulation class:
I
-20°C ÷ +40°C
Lampholder:
G13 T8 / G5 T5
Rated voltage:
230V
Frequency:
50Hz
Cable section max:
2,5 mm2
WATERTIGHT LIGHTING FIXTURE
IN STAINLESS STEEL
GAS DUST
ZONE 0 1 2 20 21 22
Usable X X X
EN 60079-0:2009
EN 60079-15:2010
EN 60079-31:2009
EN 60598-1:2008 + A11: 2009
EN 60598-2-1:1989
II 3G Ex nA IIC T4 Gc
www.palazzoli.com

43
RINO-EX SERIES
Lighting fixtures
in stainless steel-glass
with white reflector
230V 50Hz IP66
RINO SERIES
Pair of hooks for pendant
installation of lighting fixtures
RINO SERIES
Pair of swivelling supports
for wall and ceiling installation
of lighting fixture
RINO-EX SERIES
Lighting fixtures
in stainless steel-glass
with symmetrical
reflector and
fuse protection
230V 50Hz IP66
Lamp wattage
(W)
Power supply
Lampholders
and lamps
Palazzoli
code
Pack
Q.ty
1x18 electromagnetic G13 T8 822101EX 1
1x54 electronic 230VAC/DC G5 T5 822961EX 1
(1+1)x36 emergency G13 T8 822211EX 1
Equipment:
Polyamide cable gland M20.
Pair of hooks in AISI304 steel for pendant installation.
Characteristics:
Fluorescent tubes are not included.
Lighting fixtures with electronic power supply work on 50/60 Hz.
Lamp wattage
(W)
Power supply
Lampholders
and lamps
Palazzoli
code
Pack
Q.ty
(1+1)x18 emergency G13 T8 820111EX 1
(1+1)x36 emergency G13 T8 820211EX 1
Equipment:
Nickel-plated brass cable gland M20.
Pair of hooks in AISI304 steel for pendant installation.
Characteristics:
Fluorescent tubes are not included.
Lighting fixtures with electronic power supply work on 50/60 Hz.
Rotating
angle
Manufacture
material
Palazzoli
code
Pack
Q.ty
± 75° Stainless steel AISI 304 820000 1
Equipment:
Lighting fixture washers and fixing nuts.
Manufacture
material
Tube diameter
ø (mm)
Palazzoli
code
Pack
Q.ty
stainless steel AISI 304 60 820006 1
Manufacture
material
Palazzoli
code
Pack
Q.ty
Stainless steel AISI 304 820001 1
Equipment:
Lighting fixture washers and fixing nuts.
Dimensions
page47
LIGHTING DEVICES
RINO SERIES
Pair of collars for installation on
tube of painted stainless steel
lighting fixtures

44
TAIS-EX Series
ALUPRES-EX Series
Dimensions
Socket-outlets
Socket-outlets
Mounting plate
Mounting plate
Rated
current
(A)
Poles
Ø entry
cable
(mm)
A
(mm)
B
(mm)
C
(mm)
D
(mm)
E
(mm)
16
2P+Q
12÷18 380
159
335 Ø25 3193P+Q 164
3P+N+Q 175
20 / 32
2P+Q
16÷25 380
177
335 Ø32 3193P+Q
3P+N+Q 185
40 / 63
2P+Q
16÷25 423 203 370 Ø32 3543P+Q
3P+N+Q
Rated
current
(A)
Poles
Ø entry
cable
(mm)
A
(mm)
B
(mm)
C
(mm)
D
(mm)
E
(mm)
16
2P+Q
12÷18 350
150
315 M25 3003P+Q 155
3P+N+Q 160
25 / 32
2P+Q
16÷25 390
168
315 M32 3003P+Q
3P+N+Q 170
40 / 63
2P+Q
16÷25 430 188 355 M32 3403P+Q
3P+N+Q
Code
A
(mm)
B
(mm)
C
(mm)
D
(mm)
532800 125 110
609 630532802 250 215
532804 380 345
FixingFixing

45
CAM-EX Series in thermosetting
CAM-EX Series in aluminium alloy
Code
Ø entry
cable
(mm)
A
(mm)
B
(mm)
C
(mm)
D
(mm)
E
(mm)
F
(mm)
272141EX
10÷14 140
87
92 92 77 77272142EX
103
272143EX
272144EX
12÷18
175 120 125 92 110 77
272241EX
150
87
92 92 77 77272242EX
103
272243EX
272244EX 175 120 125 92 110 77
272301EX
16÷25
275 150 185 125 170 110272302EX
272303EX
272304EX 275 150 185 125 170 110
272402EX
275 150 185 125 170 110272403EX
272404EX
Code
Ø entry
cable
(mm)
Ø exit
cable
(mm)
A
(mm)
B
(mm)
C
(mm)
D
(mm)
E
(mm)
F
(mm)
272146EX
10÷14
10÷14
165 130 125 92
77 110
272147EX
272246EX
12÷18 165 130 125 92
272247EX
272306EX
16÷25 12÷18
225 170 185 125
110 170272307EX
272406EX 225
170
185 125
272407EX 165 125 185 170 110
Rated
current
(A)
Ø entry
cable
(mm)
A
(mm)
B
(mm)
C
(mm)
D
(mm)
E
(mm)
F
(mm)
A
(mm)
10-16 10÷14
175 122 25 125 92 111 78
20-25
12÷18
32-40
260 165 37,5 185 125 169 109
50-63 16÷25
Fixing
FixingFixing

46
CEE-EX Series ALARM-EX Series
TAIS MIGNON-EX Series RONDÒ-EX Series
Rated
current
(A)
Poles
A
(mm)
B
(mm)
Entry
threading
16
2P+Q 112 73 Pg 13,5
3P+Q 117 80
Pg 16
3P+N+Q 124 88
32
2P+Q
141
94
Pg 213P+Q
3P+N+Q 101
63
2P+Q
208 110 Pg 293P+Q
3P+N+Q
Internal
diameter
(mm)
A
(mm)
B
(mm)
C
(mm)
D
(mm)
E
(mm)
62 45 140 82 M20x1,5 Ø6,5
82 57 180 106 M25x1,5 Ø7

47
RINO-EX Series
RINO-EX Series
Lamp type
(W)
A
(mm)
B
(mm)
18 690 480
36-54 1300 1090
Oval lighting fixture type
(W)
A
(mm)
B
(mm)
C
(mm)
D
(mm)
E
(mm)
F
(mm)
60 199 119 100 184 112 42
75 226 122 105 210 130 42
100 295 142 127 278 170 52

48
The book “ATEX – Planning and Installation”
is addressed especially to designers, installers and maintainers
of electrical equipment installed in potentially explosive atmospheres.
There are illustrated and defined fundamental elements
to individuate ignition sources and to prevent explosions
due to electrical causes.
Numerous summary tables help the reader to apply
new legislative requirements and regulations.
It is a general legislative and technical approach,
useful for anyone that has to deal
with the explosion danger.
Presentation

49
Planning
and Installation
ATEX
This book has been written using the homonym text of Eng.Mirko Martina, member of CT 31.
Special thanks to Eng. Maurizio D’Addato, Director of the National Fire-watchers’ Corps, for
his kind permission to access the unique official statistical data that analyze the extent of
the damages suffered by people due to explosions.

50
1. ORIGINS AND REGULATIONS page 52
1.1 Introduction page 52
1.2 Relevance – Modern studies about fires and explosions in Italy page 52
1.3 Short normative history - ATEX page 53
1.4 Directives ATEX page 54
1.4.1 Directive 1999/92/EC page 54
1.4.2 Directive 94/9/EC page 55
2. TECHNICAL ASPECTS page 56
2.1 Explosion page 56
2.2 The areas at risk page 57
2.3 Explosive atmosphere at presence of gas, vapour and fog page 58
2.4 Explosive atmosphere at presence of dusts page 60
2.5 Sources of ignition page 63
2.5.1 Electric arc page 63
2.5.2 Superficial temperature of equipment page 63
2.5.3 Electrostatic discharge page 63
2.5.4 Other possible forms of ignition page 65
2.6 Evaluation of probabilities of presence of explosive atmosphere page 65
2.7 Classification of gases and dusts page 67
2.8 Level of safety for electrical equipment installed in explosive atmosphere page 67
2.9 Electrical constructions “Ex” (IEC/EN 60079) page 69
2.9.1 Directive IEC/EN 60079: General Requirements page 71
2.9.2 Methods of protection page 72
INDEX

51
3. INSTALLATION MODALITIES page 79
3.1 Electrical devices in potentially explosive areas page 79
3.2 Initial approach: data and information collection necessary for planning page 80
3.3 Responsibilities page 81
3.4 Marking page 82
3.5 Declaration of conformity page 86
3.6 Verification and maintenance page 87
3.6.1 Verification page 87
3.6.2 Verification documents page 88
3.6.3 Verification process of new plants page 89
3.6.4 Personnel qualifications page 90
3.7 Inspection schedules page 92
3.7.1 Verifications that do not depend on the protection type of equipment page 92
3.8 European vs. American perspective page 98
4. PRODUCTS INSTALLATION PARAMETERS page 100
4.1 Equipment selection page 101
4.1.1 Information and necessary data page 101
4.1.2 Selection in relation to the Hazardous Zone page 102
4.1.3 Choice in relation to the Ex equipment group page 102
4.1.4 Choice in relation to the environmental temperature page 103
4.1.5 Choice in relation to ignition temperature of gases page 104
4.1.6 Choice in relation to the ignition temperature of dusts page 104
4.2 External influences page 107

52
1. ORIGINS AND REGULATIONS
1.1 Introduction
Historically, workplace risks from electric devices originated at the beginning of 1900s, when formations of firedamp in
coal and sulphur mines led to many disasters.
An explosion of methane gas (firedamp, also called mine gas) in a coal mine caused the death thousands of workers.
Investigations were conducted in order to establish the causes of the accidents, they showed that the explosion was
provoked by the low-voltage signal system used to communicate the readiness of the coal trolleys to climb from the
bottom to the surface of the mine.
This system, composed of low voltage batteries and a siren, and wiring running along the tunnels, was believed to be
safe as it was working on low voltage and low current.
However, it was clear that without protection, the inductive energy magazined in the siren, and in the wiring itself,
would produce sufficient levels of energy to create a spark and consequently, an explosion of the dangerous mixture
of air and gas.
Therefore, the electric device and the circuits associated to it, had to be constructed in new ways to mitigate future
risks, and protect against possible damage of the devices themselves.
Evidently these types of risk do not occur only in the mining sector, petroleum and chemical industries present
obviously risks, but also a lot of food, agriculture and manufacturing and finishing industries generate as part of their
normal daily routines of atmospheres of dust and unfavorable mixtures, that are potentially explosive.
1.2 Relevance – Modern studies about fires and explosions in Italy
Percentage of deaths due to fires and explosions
(Period 2007-2011)
Fires
76%
Explosions
24%
Foodstuffs
12%
Various
16%
Pharmaceutics
5%
Chemistry
21%
Fireworks
46%
All deaths 686
All deaths 164
All deaths 43
Deaths due to explosions in industries in Italy
(Breakdown regarding typology - Period 2007-2011)
Deaths due to explosions in Italy
(Breakdown regarding typology - Period 2007-2011)
Deaths due to explosions in Italy
(Annual Breakdown in relation to the typology)
Residences Industries Railways Commercial activities Agricultural activities Auto Various Storages

53
Even today, a hundred years or so later, these matters still concern us – take for example, the measure of the tragic
relevance that is confronted in the present technical study that is taken from the official research that analyzes the
amount of fatalities and injuries in Italy in the period 2007 – 2011.
These statistics from Eng. Maurizio D’Addato, Director of the National Fire-watchers’ Corps.
They show immediately entity and dimension of the problem taken as a whole and then in a detailed way focuses on
sectors and typologies.
1.3 Short normative history - ATEX
The first Italian regulation regarding flameproof electric plants is from 1955 (D.P.R. 547). One year after the directive CEI
23-4 acknowledged the way of protection from explosions, 13 years later confirmed in the CEI 31-1, the first Directive
of Committee 31 aligned with recommendations IEC and CENELEC.
This initial choice, followed by almost 40 years of lack of new directives, conditioned the Italian electric plant design that
remained on the level of syllogism till 1994: flameproof = explosion protection, however it was acknowledged just on
the formal level. Because of the community obligation, also other ways of protection were strengthening in Europe and
in the United States.
The ATEX directive, published in 1994, but definitely in function just from the 1st July 2003, broke with the past and
established four firm points:
1. The directive itself establishes the minimum requirements of protection, that even though are coherent with the
directive in force, they are not strictly bound to it.
2. In all places that are classified as dangerous in the aspect of risk of explosion for the presence of gas or dust,
restrictions concerning requirements of security need to be followed.
3. The danger is divided into three levels and each of them concerns a particular category of requirements: the
category 1 covers the level of the highest risk (zone 0 and 20), the category 2 – the level of high risk (zone 1 and
21), the category 3 – from the quantitative point of view is the most important one, the level of risk is defined as
“normal” (zone 2 and 22). The definition “normal” is not accidental; indeed all directives of the Community impose
the highest possible levels of prevention from the formation of explosive atmospheres, in other words in normal
conditions there should exist just zones 2 and 22.
4. The declaration of conformity that meets the requirements of security has to refer to the standard or new way
of protection and to the above-mentioned categories and needs to be accompanied with a way of control of
manufacturing that guarantees the continuity of meeting such requirements during the production.
For effect of the point 1 it is not necessary to expect that the new directives would recognize new ways of protection to
gain the certification as the directive contains sufficient and detailed indications.
For effect of the point 2 there are not acknowledged anymore old implants AD-T and AD-FT based on the waterproofing
standards IP55 and IP44, now replaced with the ones in a way of protection Ex n G and D.
For effect of the point 3 the old Directive CEI 64-23 had to be replaced by new CEI 31-30 and 31-34 that introduce
more rational criterion of determination of the zone 2 amplifying considerably the field of the use of requirements of the
category 3 to which belong the typologies Ex n.
For effect of the point 4 the guarantee is extended to production and not only to the prototype subordinate to the verifying
entity; in particular the way of control of manufacturing, to put in disposition of authorities in charge to supervise, for
companies with the certification ISO 9000 becomes a certified commitment.
At last, it can be added that the new approach ATEX offers to the user the major guarantees of security together
with possibility to graduate costs for the explosion protection to the effective entity of danger; in the meantime frees
the technological research from rigid subjugation to the directive that have frequently excessive and daunting time of
preparation and transposition.

54
In this new approach there are collocated the constructions Ex n G and D represented by Palazzoli, appropriate to many
requirements of the directive ATEX and of the constructive norms CEI EN that refer to the explosion-proof technology
of the III generation.
Difference between previous normative and ATEX
1.4 Directives Atex
The principles of security against explosion are included in two Community directives known as Directives Atex: Directive
1999/92/EC and Directive 94/9/EC.
The attainment of the acceptable level is a result of the analysis of risk and in particular of minimization of two factors that
influence the likeliness of explosion, that is: the likeliness of the formation of explosive atmospheres and the likelihood
of the presence of sparks.
The eevaluation of the likelihood of the explosive formation determines the subdivision in Zones of danger according to
the origin of the explosive atmosphere in the presence of gas and dust (Directive 1999/92/EC). The evaluation of the
likeliness of sparks in the explosive atmosphere determines the protection from the trigger of the explosive atmosphere
by means of electric devices and/or components constructed in a way of protection that guarantees a level of security
that corresponds to right zone of danger (Directive 94/9/EC). The prescriptions of security of devices to install in
hazardous zones are also addressed to non-electric equipments.
As follows there are illustrated all fundamental points of the two directives.
1.4.1 Directive 1999/92/EC
The directive 1999/92/EC is a social directive that was submitted after consultation with the Advisory Committee on
Safety and Health Protection at Work. It aims to ensure the minimum requirements of safety of workers at risk from
explosive atmospheres. These objectives are prosecuted through the evaluation of the explosion risk and of the
techniques to minimize the presence of the explosive atmospheres and sparks. Shortly we can say that it is under the
directive 89/391/CEE, only that instead of occupying with workplaces in general, regulates specific provisions to follow
in places potentially at risk from explosive atmospheres.
The directive provides a classification of risk in zones, that refer to the employer and the areas in which can be produced
explosive atmospheres and it determines groups and categories of equipments that can be used in each zone. The
classification of areas is based on the frequency and the duration of the presence of explosive atmospheres.
The directive establishes the minimum requirements for improving the safety and health protection of workers potentially
at risk from explosive atmospheres. These requirements are explicit through determined obligations that have to be
absolved by the employer. In particular, the employer has to evaluate the explosion risks, at the same time taking into
consideration:
petrol petrol
some
meter
Before Now

55
• likeliness and duration of the presence of explosive atmospheres
• likeliness of presence, activation and efficiency of the ignition, including electrical discharge
• characteristics of the plant, substances that are used, process and their possible interactions
• entity of predictable events
• evaluation also of those areas that are not at risk but that are in connection through openings with areas at risk
Moreover the employer in the scope of prevention under the directive 89/391/CEE (ex DLgs 626/94 now DLgs 81/08)
has the duty to enforce some principles that are fundamental to prevent the formation of explosive atmospheres, to
avoid the ignition of explosive atmospheres and to mitigate the consequences of the explosion in order to guarantee
the health and safety of workers.
To achieve this aim the employer has to take necessary measures so that in the areas at risk from explosive
atmospheres, it is possible to carry out the work in safe conditions and that there is an adequate control to limit the
risk during the work.
Furthermore, the employer should divide in zones the areas in which may be formed explosive atmospheres and needs
to assure that in these zones are guaranteed the minimum safety prescriptions. If necessary, these areas are supposed
to be signed that are at explosion risk.
Sign that identifies an area in which an explosive atmosphere can be formed
1.4.2. Directive 94/9/EC
The 94/9/EC is a directive of product whose objectives of Essential Safety Requirements (ESR) are related to the
construction of electrical and non-electrical equipment in order not to be a source of the sparks in explosive atmospheres,
depending on the likelihood of the presence of explosive atmospheres. The principal recipients of the directive are
Manufacturer or Importer of the device, anybody that enters in the market of the European Community, a product that
is meant to be installed in the explosive atmosphere.
The directive 94/9/EC concerns all equipments that are supposed to be installed in places at risk of explosion, both
electrical and non-electrical (mechanical) equipments.
It is a directive of “new approach” as it does not furnish specific techniques, but essential safety requirements, in
connection with articles of the principal test.
In the field of application there are included:
- equipments: machines, materials, fixed and mobile devices, control devices, instrumentation and systems of
detection and prevention that alone or combined are used in the production, transport, storage, measurement,
regulation and conversion of energy and transformation of material and that because of the sources of sparks are
at risk of explosion;
- safety systems: safety, control and regulation devices that are meant to be used outside of explosive atmospheres
but they are necessary and useful to the safe functioning of devices and protection systems as far as it concerns
the explosion risks (barrier Ex “i”);
- protection systems: devices that differ from components of the above defined devices, whose function is to block
explosions in their source and/or circumscribe the zone in which they occurred;
- components: essential pieces to the safe functioning of devices and protection systems without autonomous
functioning.

56
2.1 Explosion
An explosion is a reaction of oxidation. The reaction of oxidation, that can be defined as combustion, provokes the
formation of heat that is usually accompanied by visible flame. The combustion is an exothermic redox which means
that a compound tarnishes while the other reduces releasing energy and forms new compounds, mostly carbon dioxide
and water. For example, in the case of hydrocarbons, carbon tarnishes and oxygen reduces.
The principal products of combustion are:
• high emission of heat (exothermic reaction);
• high emission of gas at high temperature.
The reaction happens only if there are the three following components present (at the same place and at the same time):
• fuel: substances in the form of gas, vapour, fog or dust;
• combustive agent: it is an oxidative agent, usually oxygen present in the air;
• ignition sources: any event (spark, flame, temperature, etc.) that is a source of energy.
The fuel and the combustive agent (oxidant) are reagents of the reaction of redox; the ignition source is a source that
forms energy that is necessary to initiate the reaction (energy of activation).
The necessary presence of fuel, combustive agent and primer at the same time is illustrated by the fire triangle (or
combustion triangle).
Once the reaction is triggered, it emits heat that is absorbed by the layers of combustible mixture that warm up and
react with high velocity.
In this way a reaction front is formed, often called flame front, that moves from the combusted mixture to the non-
combusted mixture, provoking the ignition of the remaining combustible mixture.
The speed with which the flame front moves is the propagation speed of combustion.
The phenomenon “explosion” is verified when the energy released from the combustion and the propagation speed
are too much elevated to be absorbed from the environment and in the consequence increases temperature in a short
time and at little space that creates a pressure wave which spreads in the environment.
Not all of the combustible-combustive mixtures, even if they are triggered, finish with an explosion.
The conditions that determine if an atmosphere is explosive are physical/chemical characteristics of the fuel (explosive
properties).
Moreover, with the term “explosive atmosphere” it is intended a mixture characterized by:
2. TECHNICAL ASPECTS
Fire triangle
• flammable substances in the state of gas, vapour, fog
or dusts and fiber with determined properties and in
determined concentrations in volume;
• the air in atmospheric conditions;
• as consequence of an ignition, the combustion spreads to
the mixture that is not burnt.
The atmospheric conditions occur when the concentration of
oxygen in the air stands for approximately 21% and they include
pressure and temperature variations over and under levels of
1 atm and 20°C which do not influence much the explosive
properties of substances.
An atmosphere that is susceptible to transform to an explosive
atmosphere as a cause of local and/or operative conditions is
called “potentially explosive atmosphere”.
Also the ignition that is necessary to start the explosive reaction
has to have determined properties, indeed the energy of ignition,
measured in Joule, has to be bigger than a determined value
(minimum) threshold that differs for each combustible substance,
below which does not originate any reaction.

57
2.2 The areas at risk
Many industrial processes require the use of inflammable or combustible substances that are stored, manipulated,
transported and in the end utilized inside of the production process. Apart from the explosive substances or chemically
instable, for which there is a notable risk, there is a high number of substances that have in certain conditions a
characteristic to initiate an explosion.
The substances that can originate explosive mixtures are utilized in numerous operations that take part of normal
working activities. For example in painting activities, flour milling, charging batteries, storage operations and transport
of gas substances, etc.
It results natural to consider the explosion risk in chemical and/or petrochemical work environments. Nevertheless, we
have to take into account that in many other activities (for example woodworking, mills, distilleries, etc.) the presence of
inflammable mixtures is also very probable and it should be evaluated and prevented. Many work activities that involve
substances at risk, are integral part of normal activities inside of work environments that we can define as “ordinary”. In
such work environments it is not automatic to think of the explosion risk.
An extraordinary example is an accident that was registered in the end of 2011. In Shanghai in Pegatron, a subsidiary
of a company in Taipei that works for Apple, an explosion occurred with a result of 61 people injured. The cause of the
explosion was aluminium powder which is used to polish the cases for iPad. However more serious was an accident
that occurred in May 2011 in a plant of Foxconn Technology, the biggest producer working for Apple. The 20th May in
Chengdu, in China the explosion of (combustible) aluminium powders caused the death of three workers and 15 others
were injured. These episodes should lead us to the conclusion that the risk is high at work places where normally we do
not expect the presence of the explosive atmosphere, which is a consequence of our underestimation of the possibility
of the formation of explosive mixtures.
Consequences of an explosion in an area at risk

58
2.3 Explosive atmosphere at presence of gas, vapour and fog
There are illustrated some properties of each inflammable substance that can originate an explosive atmosphere in form
of gas or vapour mixed with the air. These properties are fundamental for the evaluation of the risk and for the choice
of electrical devices (classification of gas).
- Limits of inflammability
A substance in form of gas, vapour or fog that is mixed with the air, becomes an explosive atmosphere only if the
concentration of the same substance in the air is sufficient to make it inflammable. Air-fuel mixtures are inflammable
only at limited fuel concentrations in the air that are defined by inferior and superior limits.
Graphical representation of inflammability limits
Two limits represent the minimum and maximum fuel concentration that
allows the spread of flame. The concentration is usually expressed as
a volume percentage.
To determine the substance explosivity there are two limits defined:

‐ LEL (lower explosive level): gas or vapour inflammable concentration
in the air, under which the atmosphere is not explosive
‐ UEL (upper explosive level): gas or inflammable vapour concentration,
over which the atmosphere is not explosive
In the table explosive limits of some gases and vapours are quoted; some of these fuels have explosive intervals that
are quite narrow; the others have an extended explosivity and can be considered “more dangerous”, as little emissions
form explosive atmosphere. In some cases the superior limit is so high that some substances represent an UEL equal
to 100% as their vapours can explode practically with no need of air.
Substance LEL% UEL% Substance LEL% UEL%
hydrocarbons alcohols
Methane 5 15 Methyl alcohol 6,7 36
Etane 3 12,4 Ethyl alcohol 3,3 19
Propane 2,1 9,5 Butyl alcohol 1,7 12
Butane 1,8 8,4 inorganics
Ethylene 2,7 37 Ammonia 15 28
Propylene 2,4 11 Hydrazyne 4,7 100
Acetylene 2,5 100 Hydrogen 4,0 75
Benzene 1,3 7,9 ketones
Pentane 1,4 7,8 Acetone 2,6 31
Hexane 1,2 7,4 Methyl ketone 1,9 10
Examples of inflammability limits of some gases and vapours (atmospheric conditions)
- Flash point
When the explosive atmosphere is generated by combustible liquids, for example inflammable liquid in an open
container, the characteristics of the combustible that expresses inflammable properties and of capacity to form explosive
atmospheres, is the temperature of inflammability.

59
The flash point is the lowest temperature at which at pressure of 760 mmHG vapours are formed in such amount that
in the presence of oxygen and of the ignition the phenomenon of combustion does occur.
Here below there are some examples of inflammable liquid substances and the relative flash point.
Substance Tinf [°C] Substance Tinf [°C]
Petroleum -20 Ethylic ether -45
Gas oil +55 Acetone -17
Benzene -11 Ethyl acetate -4
Ethyl alcohol +12 cyclohexane -20
Examples of inflammability temperatures of some substances
The flash point is an important property to ensure safety against explosions, as it is the basic parameter to evaluate
if an inflammable liquid substance can form explosive atmosphere in a determined work environment with the proper
environmental temperature in which it is stored, managed, transported or produced.
- The minimum energy of ignition
To trigger the explosive atmosphere it is necessary to form quantity of energy called energy of ignition. This one changes
according to the concentration of the combustible and tends to a minimum when it approaches the stoichiometric
concentration, called the minimum energy of ignition. The minimum energy of ignition is a specific characteristic of each
substance. Therefore in literature there are described curves of ignition for each inflammable substance.
The energy of ignition increases notably with concentrations that correspond to inferior and superior limits of
inflammability.
Ignition curves of hydrogen propane
The graph illustrates the minimum energy of ignition of hydrogen that is considerably inferior: which means that there
is required less energy to trigger the explosive atmosphere of hydrogen compared with the explosive atmosphere of
propane.
- The temperature of ignition (autoignition)
The temperature of autoignition is the lowest temperature at which the combustible-combustive mixture needs to be
brought, so it ignites itself automatically.
LEL % UEL %
IDROGENO
LEL % UEL %
LEL % UEL %
1,0
PROPANO
IDROGENO
LEL % UEL %
innesco(mJ)
Energia minima di innesco
Energiafiinnesco(
0,1
Energia
0 10 20 30 40 50 60 70 80 90 100
0,01
0 10 20 30 40 50 60 70 80 90 100
Concentrazione in volume (%)
Ignitionenergy(mJ)
Concentration in volume (%)
PROPANE
hydrogen
Minimum ignition energy
Minimum ignition energy

60
The temperature of ignition of a substance is not correlated to the minimum energy of ignition, therefore it is considered
as a specific quantity of the substance. For this reason, to classify gases and vapours both parameters are utilized.
Moreover, the temperature of ignition is one of parameters of fundamental inflammable substances for the choice of the
electrical construction.
Since the determination of the temperature of ignition is strongly influenced by conditions in which it is obtained, in
technical literature there are tables containing temperatures of ignition with an elevated margin of safety. However, in
the case of different values of the same substance it is good to choose the lowest one.
2.4 Explosive atmosphere at presence of dusts
When an explosive phenomenon is taken into consideration, it is natural to think of the ignition of explosive atmospheres
air-gas/inflammable vapours. However it is less intuitive to think that an explosion can be generated by combustible
dusts, even if at many work places they are manipulated, maintained and are present.
The first explosion caused by dusts which is documented occurred in 1785 in Turin in a mill producing flour. For many
years had been spread belief that the explosions of dusts would occur just at presence of gas, as well as the explosions
in carbon mines where the accident happened at presence of “mine” gas.
In 1845 Faraday demonstrated as the first that carbon dust could trigger and explode even in absence of gas. Therefore
there were needed numerous explosive accidents, also with cases of death, to understand the phenomenon of explosion
of combustible dusts apparently non dangerous, such as farming dusts. The idea that dust could explode becomes even
less intuitive if it derives from production of materials that at the same solid state are not inflammable. For example in the
case of aluminium production, obtained fine powders in some conditions of granulometry and in certain concentration in
the air, may generate the explosion.
Generally a dust is a group of solid particles that are present in the atmosphere and tend to stratify for the proper mass.
However they can remain suspended in the air for a certain period. A dust becomes combustible when it is able to react
with oxygen in the atmosphere (the particles tarnish), to burn in layers (becoming incandescent) and to form explosive
mixtures with the air. In general this happens with dusts with granulometry < 0,5 mm. The risk of explosion increases
with diminution of dimension of dust particles.
The risk correlated to the combustible dust can occur due to:
1. Formation of dust clouds
The suspended dust in the air forms a cloud of combustible (dust) and combustive agent (the air) in which the
good mixture and small dimensions of particles (inferior granulometry from 0,5 mm) favour the oxidation which
evolves at the speed enough elevated to cause the explosion. The dust cloud generates the risk of explosion.
In general the formation of the dust cloud occurs in consequence of an operation of the production cycle (emptying
sacks, loading of the system of containment, working machine tool, etc.). Therefore, a dust cloud can be formed
with the raising of a layer of dust firstly deposited.
2. Formation of a layer of dust
When the dust deposits at surface, accumulates and if it is not removed, it forms a thick layer (from few mm up
to dozens mm) that depends on the frequency of cleaning (removal of the layer).
The combustible dust layer generate the following risks:
1. It can raise in a cloud because of the wind or in the worst case as an effect of a previous explosion. In the
last case the wave of pressure of the explosion originated from a cloud, rises the layer that forms a new cloud
which being immersed in the high-temperature combustion, triggers immediately generating an explosion with
the power that is superior to the previous one (dominoes effect of the dust explosion).
2. A dust layer that settles at the surface of electrical components and is not removed frequently, worsen
their cooling with an increase of temperature of surface and the risk of ignition of the dust layer for its slow
combustion (risk of fire).

61
In general, the explosion of dusts occurs if the following factors are present:
- dusts are combustible;
- dusts are spread in the air (cloud);
- the granulometry is right to spread the flame;
- the dusts concentration in the air is in the area of explosibility;
- the combustive agent has sufficient energy.
The fire triangle should be modified when it regards dusts and it is called “explosion pentagon”:
Pentagon explosion of combustible dusts
As follows there are quoted some physic-chemical properties of combustible dusts that are fundamental for the risk
evaluation and for the choice of the electrical devices (dusts classification).
- Combustibility
The dust combustibility is an attitude to burn in the layer. It is determined through laboratory tests in which the dust
layer of big dimensions gets triggered through a filament of 1000°C. In this way it is observed the capacity of ignition or
combustion spread in the layer and it is evaluated in the basis on are defined the combustibility groups.
Moreover, the test is utilized to determine the Temperature of ignition in layer.
Combustibility class Evaluation
BZ 1 Does not catch fire (incombustible)
BZ 2 Takes fire for a short time and then puts out rapidly
BZ 3 Becomes incandescent (burns) locally without spreading
BZ 4 Becomes incandescent (burns) and spreads
BZ 5 Produces vivid fire that spreads
BZ 6 Produces very rapid combustion
Combustibility classes for dusts
- Explosibility
The dust explosibility is its capacity to explode in a cloud, which is verified through laboratory tests. An air-dust mixture
in a cloud is triggered inside of a closed container and there are two measured variables that represent the explosion
violence of a cloud in a confined space: the maximum overpressure of the explosion (pemax
) and the maximum velocity
of the growth of pressure (dp/dt)max.
In general dusts are explosive if it is possible to register pressure of explosion superior to the value 666 Pa (0,0066 bar),
beyond which there are verified harms to human, animals and objects.
It is possible to associate to each dust a “grade” of explosibility: in function of the maximum velocity of pressure growth
(dp/dt)max
, it is determined a constant defined as an explosion index Kst.
Depending on the value of Kst
of the dust it is attributed an Explosion group St.
SORGENTE DI INNESCOSORGENTESORGENTESORGENTESORGENTE DIDIDIDI INNESCOINNESCOINNESCOINNESCO
AMBIENTE CONFINATO
DISPERSIONE DI
PARTICELLE IN ARIA
AMBIENTE CONFINATO
(NUBE DI POLVERE
CONFINATA)
(FORMAZIONE DI NUBE)
OSSIGENO
IN ARIA
POLVERE
COMBUSTIBILE
IGNITION SOURCE
OXYGEN
IN AIR
OXYGEN
IN AIR
PARTICLES
DISPERSION IN
THE AIR (CLOUD
FORMATION)
LIMITED
ENVIRONMENT
(LIMITED DUST
CLOUD)

Lewden Electrical Palazzoli ATEX Solutions for Explosive Atmospheres - Industrial Plugs & Sockets, Enclosures, Cable Glands, Control Devices, Lighting Fixtures & Signalling Devices

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