Hensel with its Enysun standardized photovoltaic distributors is the pioneer in the propagation of safe technology for PV generator junction boxes. The selection criteria for the correct overload protection for both crystalline and thin film panels differ in some respects. Elektro Tipp offers some suggestions....

1. Strong and long-term protection
with Hensel PV Generator Junction
Boxes:
DK Cable junction boxes
2
1.5 to 240 mm , IP 54-67
THE ELEKTRO
Email: info@hensel-electric.in ∙ www.hensel.in
 PV generator junction boxes,  protection class: II  Customer information for electro-technical specialists 3/2010
ready for connection and wired  degree of protection: IP 65 KV Small-type distribution
 suitable for outdoor installation, UV resistant  rated voltage: UOC STC DC 1000 V boards
 with stainless steel external brackets for external 3 to 54 modules, IP 54- 65
fixing of enclosures
Phone: +91-44-3727 0202
Fax: +91-44-3727 0200
"Now we only have
Distribution boards to connect the panels to
the inverters!"
Combinable enclosure system
with door up to 250 A, IP 65
Dear Reader,
Sriperumbudur - 631 604 ∙ Kanchipuram Dist, Tamil Nadu
First of all, I would like to thank all our
Collection of new ideas in the Electrotechnical Industry
Mi Distribution boards customers and business partners for the
up to 630 A, IP 54-65
fine support and attendance at the open-
ing of our new plant on 18 June 2010 in
Sriperumbudur near Chennai.
We received very many congratulations
Sunguvachathram - Walajabad Road
4th km behind Samsung/Flextronics
and much approval for our new domicile
and we are happy that from this location
Cable entry systems
we can now serve both our Indian and "Stop, don't we even
New in our range of PV generator junction boxes: also our South-East Asia markets even have to install protection
PV generator junction boxes PV generator junction boxes
better than before. devices here?"
with string overload protection with blocking diode Mr. R. Rajesh and his staff tackled the
move and all the tasks associated with
Protection devices in
DC Generator disconnect switch DC Generator disconnect switch
the start at the new location with great
Mi PV 3611 12 x PV string on
1 x inverter input
new Mi PV 4311 12 x PV string on
1 x inverter input
new Construction board panels
up to 630 A, IP 44-65
energy. In the name of my family and the
German management, I would like to very
Mi PV 3931 24 x PV string on new Mi PV 4631 24 x PV string on new cordially thank everybody who contrib-
PV Generator Junction
1 x inverter input 1 x inverter input
uted to the successful realization of this
with DC generator disconnect switch with DC generator disconnect switch project.
with DC type 2 surge arrester with DC type 2 surge arrester
In future, also in India and the other states
Mi PV 3621 12 x PV string on new Mi PV 4321 12 x PV string on new of South-East Asia, the utilization of solar
Boxes:
1 x inverter input 1 x inverter input Photovoltaik distributors
energy for the generation of electricity will
Mi PV 3941 24 x PV string on
1 x inverter input
new Mi PV 4641 24 x PV string on
1 x inverter input
new that meet the standards Industrial Electric Power Distribution Systems
be an area of great importance. It is here
that Hensel is a pioneer in the urgently
necessary and safe technology of the PV
Generator Junction Box. Both for the use
of crystalline and also thin-film panels,
Investments effectively protected
Please ask for the new product information
"Safe product solutions conforming to standards
there are various selection criteria for the
against harm!
98 17 0654 02.10/101/12
correct overload protection required. For
Hensel Electric India Pvt Ltd
Professional Photovoltaic Distributors
for photovoltaic plants ON-grid systems" with the all the specialists, we have developed a
additions to the range at www.hensel.in!
Investors for PV systems expect special attention is to be paid to
simple flowchart how to easily and rapidly
approach this subject. long-term profits of the financial the choice of suitable, efficient
35 Kunnam Village
We are confident that your task require- expenditures connected with the Photovoltaic modules and solar
NEW
ments can also be safely and reliably construction and running of a inverters as well as to the electri-
solved with our product solutions.
photovoltaic plant. cal protection concept.
Delivery in India via Hensel authorized Product information as at: 9/2010
distributor network spanning 130 cities and
Safe product solutions
In order to achieve this goal
R. Rajesh
conforming to standards for
Photovoltaic plants
industrial centers. New product ON-grid systems
Managing Director F.G. Hensel.
information
with the proven
�
�
NEW:
PV Generator junction boxes
Solar inverter collectors
Hensel Electric India
Managing Director
Professional protection of investments
Delivery in South East Asia via Hensel and tested photo-
� PV Generator junction boxes with
string overload protection or
blocking diodes
Pvt Ltd
Gustav Hensel GmbH & Co. KG starts already with the correct choice of
authorized distributor network in all ASEAN voltaic solutions info@hensel-electric.in
countries. from Hensel!
Industrial Electrical Power Distribution Systems www.hensel.in
components ...

2. How to choose the correct overload protection for PV generator junction boxes:
Required protection
device in PV generator
PV panel String overload DC generator DC surge arrester
Blocking diode junction boxes
technology protection disconnect switch for PV plants (SPD)
Generator junction box with
NO terminals
Is
string Is DC
overload generator Is DC surge
NO NO Generator junction box with
protection disconnect arrester
Crystalline YES DC surge arrester for PV plants
required? switch re- required?
panels quired?
  
Generator junction box with
DC generator disconnect switch
NO
YES
Generator junction box with
Is DC surge
YES DC generator disconnect switch and
arrester
YES DC surge arrester for PV plants
required?

Is DC
generator Is DC surge
NO NO
disconnect
Which switch re-
arrester Generator junction box
required? with overload protection
PV panel quired?
technology is   Generator junction box
YES with overload protection and
used? DC surge arrester for PV plants
YES
Generator junction box with
Is DC surge NO overload protection and
arrester DC generator disconnect switch
NO required?
Generator junction box
 with overload protection,
YES DC generator disconnect switch
and DC surge arrester for PV plants
Thin-film Are Is DC
panels blocking YES
generator Is DC surge
disconnect NO NO Generator junction box
diodes arrester
required? switch re- with blocking diodes
required?
 quired?
Generator junction box
 
YES with blocking diodes and
DC surge arrester for PV plants
Generator junction box
YES NO

 with blocking diodes and
Manufacturer's instruc- Please check, if overload DC generator disconnect switch
tions must be checked! protection is needed, see Is DC surge
arrester Generator junction box
the requirements of 
YES with blocking diodes,
IEC 60364 -7-712 Please check, if additionally a required?
DC generator disconnect switch
Part 712.433.1 DC generator disconnect switch  and DC surge arrester for PV plants
must be used. This can be inte-
Manufacturer's instruc- IEC 60364 -7-712 grated already in the solar inverter! 
tions must be checked: Part 712.433.1 See the requirements of
Please check, if a surge protection
If thin-film panels are not re- Overload protection may be IEC 60364-7-712 Part 712.536.2.2.5! device (SPD) is necessary.
verse current proof, blocking omitted to PV string and PV
diodes must be used. array cables when the continu- IEC 60364 -7-712 - If DC lines are wired from one lightning protection zone into
The manufacturer indicates ous current-carrying capacity of Part 712.536.2.2.5 another, a type 2 surge protection device (SPD) must be
the number of parallel strings, the cable is equal to or greater A switch disconnector shall installed in the proximity of the feed-through for cables.
for which no blocking diodes than 1,25 times ISC STC at any be provided on the DC side - Is an outside lightning protection installed, then also an
are needed. location. of the PV inverter. internal overvoltage protection is necessary.
(ISC STC = Short Circuit Standard Test
Condition)