The Patol analogue linear heat detection cable (LHDC) is designed to detect fires and overheating in areas that cannot support other detection methods. It can detect hot spots along its entire length and trigger alarms. The cable functions by monitoring the resistance of its dielectric insulation, which has a negative temperature coefficient, between the central conductor and outer braid layer. It is used with monitoring devices and can be installed in hazardous areas with intrinsically safe barriers. The cable comes in various outer sheath options for mechanical, chemical, or combined protection, and is suitable for a wide range of applications such as tunnels, conveyors, and industrial facilities.

1. Patol Limited, Rectory Road, Padworth Common, Reading, Berkshire, RG7 4JD Tel: +44 (0)1189 701 701 Email: Info@Patol.co.uk D1184-4
Analogue
Linear Heat Detection Cable LHDC
The Patol analogue linear heat detection cable (LHDC) is de-
signed to provide early detection of fire and overheating in
circumstances where other forms of detection would not be
viable, either due to inability to sustain the environment
requirements or through prohibitive costs.
Extensive single zonal lengths of the LHDC may be installed
with the ability to trigger alarms for hot spots occurring on very
small sections of the overall cable.
LHDC Analogue is a coaxial cable constructed with a copper
coated steel central conductor, an inner insulation (dielectric),
a tinned copper braid layer and an overall protective sheath.
The primary mechanism of heat (fire) detection is that the
resistance of the dielectric, monitored between the central
conductor and braid layer, has a negative temperature
coefficient (NTC).
Analogue cable is employed in conjunction with an end of line
terminating device and a zone monitoring unit or control panel
with an appropriate LHDC interface channel.
LHDC may be installed in Hazardous areas by means of
Intrinsically safe zener barriers. Similarly when the protected
area is remote from the monitoring equipment interposing
cables may be employed.
Applications
Features
Adjustable Alarm set point
Recoverable and resettable operation
Can detect hot spots
Zones of up to 500m in length
Mechanical & Chemical protection available
Easy to install
Compatible with a full range of monitoring devices
RoHS compliant — Lead Free
Cable Tunnels, Ducts & Mezzanines
Escalators & Moving Walkways
Petro-Chemical Storage Tanks / Rim Seal
Protection
Paint Shops & Spray Booths
Conveyors - Coal, Wood Sulphur.. etc
Ceiling Voids & Attic Spaces
Road & Rail Tunnel Carriageways
Nuclear Reactor Plant Areas
Refrigerated Stores & Cold Rooms
Electrical Control & Switchgear Cabinets
Warehouse High Rise Pallet Racking
Oil Rigs & Off Shore Platforms
Fume Cupboards & Glove Boxes
Grain Silos & Agricultural Storage
Road / Rail Vehicle Engine Compartments
Steam pipe Leaks & Trace Heating Faults
Product Lines - Flanges, Valves & Pumps
Computer Room under Floor Cable Voids

2. Patol Limited, Rectory Road, Padworth Common, Reading, Berkshire, RG7 4JD Tel: +44 (0)1189 701 701 Email: Info@Patol.co.uk D1184-4
Analogue
Linear Heat Detection Cable LHDC
1 10 100 300
50
60
70
80
90
100
110
120
130
140
150
DETECTIO N POINT ALARM CHARACTERISTICS
KEY
3V Set Point
2V Set Point
1V Set Point
Detector Length - m
65
118
Specification
Outer Sheath:
Red PVC - Standard
Black Nylon (Rilsan) - Chemical Protection
Stainless Steel & PVC - Mechanical Protection
Stainless Steel & Nylon (Rilsan) - Mechanical &
Chemical Protection
Outer Diameter:
Red PVC: 2.8 - 3.0 mm
Black Nylon (Rilsan): 4mm
Stainless Steel & PVC: 5 mm
Stainless Steel & Nylon (Rilsan): 5 mm
Minimum Operating Temperature: -20°C
Minimum Installation Temperature: 0°C
Weight 1km on the reel:
Red PVC: 19kg
Black Nylon (Rilsan): 19kg
Stainless Steel & PVC: 21kg (500m reel)
Stainless Steel & Nylon (Rilsan): 21kg (500m
reel)
Tensile Strength: 200 Newtons
Description Part Number
Red PVC 700-001
Red PVC S.S* 700-005
Black Nylon 700-003
Black Nylon S.S* 700-004
*Stainless Steel Braid
Ordering Information
Controllers and Termination boxes
used with Analogue cables:
Description Part Number
LDM-519-LP 700-201
LDM-519-SEN-N 700-305
LDM-519-ACT-N 700-304
EU-R 19” Rack Mount refer D1216
EOL & Through boxes refer D1120
LHDC Analogue cables
Zone Monitors are equipped with sensitivity / trip
adjustments. The graphs show three typical settings;
3V, 2V and 1V..
This example shows a typical application where 300m
of Linear heat Detection Cable is employed in con-
junction with a zone monitor adjusted for a 3 Volt set
point.
 The upper graph shows that a temperature
elevation of a 10m section of the zone will
produce an alarm trigger at a maximum of
118°C
 The lower graph shows that the whole of the
zone will with stand ambient temperatures up
to 53°C without any alarm triggers
 Margin and tolerance are applied to the
curves. In practice the withstand will be
greater than 53°C.
Note: For further information refer to full LHDC Data
Sheet.
25
30
35
40
45
50
55
60
65
70
75
30 100 1000300
AMBIENT NO N ALARM CHARACTERISTICS
Detector Length - m
53
Temperature°C
Temperature°C