The document describes the Linear Heat Detecting Cable (LHDC) which is designed to provide early detection of fires and overheating. It can detect hot spots along extensive cable runs of up to 500 meters in length. The cable has an adjustable alarm set point and is recoverable, resettable, and compatible with various monitoring devices. It can be installed in hazardous areas and remote locations. Common applications include cable tunnels, conveyors, warehouses, oil rigs, and more. The cable comes in various sheath and braid options with temperature detection down to -20°C. It is employed with end of line terminators and zone monitors to detect temperature increases.

1. Analogue
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Fax: +44 (0)191 477 5371
Email: northernsales@thorneandderrick.co.uk
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Linear Heat Detecting Cable LHDC
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
Applications
The Patol analogue linear heat detector cable is designed 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.
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 Leeks & Trace Heating Faults
Product Lines - Flanges, Valves & Pumps
Computer Room under Floor Cable Voids

2. Analogue
Linear Heat Detecting Cable LHDC
Zone Monitors are equipped with sensitivity / trip
adjustments. The graphs show three typical settings.
DETECTIO N POINT ALARM CHARACTERISTICS
150
This shows a typical application where 300m of Linear
heat Detection Cable is employed in conjunction with a
zone monitor adjusted for a 3 Volt set point.
KEY
140
3V Set Po in t
130
2V Set Po in t
120
1V Set Po in t
118

The lower graph shows that the whole of the
zone will with stand ambient temperatures up to
53°C without any alarm triggers

110
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

Margin and tolerance are applied to the curves.
In practice the withstand will be greater than
53°C.
100
90
80
70
65
60
50
1
10
100
300
D etector Length - m
AMBIENT NO N ALARM CHARACTERISTICS
Note: For further information refer to full LHDC Data Sheet.
75
70
65
Specification
60
Temperature °C
Temperature °C
Refer to the example shown:
55
Outer Sheath:
Red PVC - Standard
Black Nylon (Rilsan) - Chemical Protection
Stainless Steel & PVC - Mechanical Protection
Stainless Steel & Nylon (Rilsan) - Mechanical &
Chemical Protection
53
50
45
40
35
30
Outer Diameter:
Red PVC: 2.8 - 3.0 mm
Black Nylon (Rilsan): 4mm
Stainless Steel & PVC: 5 mm
Stainless Steel & Nylon (Rilsan): 5 mm
25
30
100
300
1000
D etector Length - m
Ordering Information
Controllers and Termination boxes
used with Analogue cables:
LHDC Analogue cables
Description
Part Number
LDM-519-LP
700-201
LDM-519-SEN-N
700-305
LDM-519-ACT-N
700-304
EOL Termination box 700-505
Through connector box 700-506
Description
Red PVC
Red PVC S.S*
Black Nylon
Black Nylon S.S*
*Stainless Steel Braid
Part Number
700-001
700-005
700-003
700-004
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
Tel: +44 (0)191 490 1547
Fax: +44 (0)191 477 5371
Email: northernsales@thorneandderrick.co.uk
Website: www.heattracing.co.uk
www.thorneanderrick.co.uk
Patol Limited