Frequently Asked Questions

Yes. In certain applications it may be desirable or necessary to use non-sensing leader cable between a ProReact Analogue control unit and the detection cable. This may be required if the expected ambient temperature range, or other environmental conditions, where the Analogue LHD cable is to be used is greater than the maximum ambient temperature range for the control unit.

The maximum length of leader cable that can be used per ProReact Analogue LHD system is 250 metres. Thermocable can manufacture and supply leader cable that is compatible with its ProReact Analogue LHD cable. Please contact us or refer to the installation manual if you require further information.

Please contact us directly and we can provide this free of charge.

UL approval has been granted for two versions of control unit. One is a self-contained unit or, for finer control, a version requiring a laptop prevents uninvited system access via a software programme.

Cable zone lengths can vary from 30 metres to 500 metres in length.

Please find below the list of components certified according to UL521:

• ProReact Analogue LHD cable – PVC
• ProReact Analogue LHD Cable – Nylon
• ProReact Analogue Control Unit – Self-Programmable inc. EOL unit
• ProReact Analogue Control Unit – Laptop-Programmable inc. EOL unit

Thermocable recommends against installing its ProReact Analogue linear heat detection cable across varying ambient environments as this can interfere with the operation of the system. We recommend that multiple ProReact Analogue LHD systems are used in this instance (one for each different environment) or a digital linear heat detection system is installed as it would not be affected by varying ambient temperatures.
We also insist that the detection cable or end of line unit do not come into contact with any material that acts as a heat sink. A silicone sleeve (C1283) should be used to support the detection cable to a fixing clip to avoid heat transfer and end of line units should not be installed directly onto metal objects.
System designers and/or installers should ensure that the detection cable is spaced at less than or equal to the maximum approved spacing in the relevant or local building regulations or fire safety standards.

The low smoke zero halogen outer coat maintains flexibility at low temperatures and enables the detection cable to operate continuously in temperatures as low as -60⁰C. The maximum ambient operating temperature is determined by the alarm temperature and can be found in the installation manual.

The low smoke zero halogen outer coat has good resistance against ammonia, copper nitrate, hydrofluoric acid and acetic acid.

Please contact us if you have a question on the chemical compatibility of this material.

Thermocable’s ProReact Plus Digital LHD cable is both UL and ULC approved. This approval covers both the low smoke zero halogen outer coat and the optional stainless steel outer braid.

Low smoke zero halogen cables are being increasingly specified and used in environments where smoke and harmful emissions released in the event of a fire could endanger human life. ProReact Plus Digital LHD cable is a low smoke zero halogen, UV stable and hydrocarbon resistant alternative to traditional digital linear heat detection cable.

The low smoke zero halogen outer coat has good resistance against ammonia, copper nitrate, hydrofluoric acid and acetic acid.

Please contact us if you have a question on the chemical compatibility of this material.

This detection cable is available in 100 metre, 200 metre or 500 metre reel lengths as standard. Non-standard lengths can be supplied but will incur a small surcharge. Please note that the maximum available reel length is 500 metres per spool.

Yes. Many fire alarm control panels and building management systems provide outputs which can be programmed to activate when a certain input is triggered such as the detection of a water leak.
These outputs are often used to activate/deactivate door retaining magnets, roller shutter doors or similar things but they are ideally suited to activating electric solenoid valves controlling the flow of water.

In most cases, the alarm volt-free relay contacts on the ProH2O Professional or Module unit will be used to trigger an alarm condition on the fire alarm control panel or building management system by switching in a low resistance. The control panel can then be programmed to activate a particular output operating an electric solenoid valve switching off the flow of water.

Yes, the ProMinder Heating Cable can be extended with the same colour (or type # of) cable as has been installed up to the maximum length for that cable. Any joints between lengths of heating cable should be made in an IP65 or greater junction box with the appropriate cable glands.

Yes, the ProMinder Heating Cable can be repaired. If a small section (less than 300mm) is to be replaced this can be done with a 4 core “cold lead” where each conductor has a sufficient cross-sectional area. If more than 300mm is to be replaced this must be done with the same colour cable as is installed. Do not mix different colour cables together on the same circuit. Any joints between the cold lead and heating cable, or between lengths of heating cable should be made in an IP65 or greater junction box with the appropriate cable glands.

Yes, this is possible. Please note that two lengths of digital linear heat detection cable should be connected using a junction box.

Yes, all Thermocable’s control or interface units require a 24V power supply.

Yes. For Class A1I / A2I, 54⁰C and 64⁰C alarm settings, the rate-of-rise alarm is activated when 2 to 5% of the sensor cable is heated at more than 15⁰C per minute for more than 3 minutes.

Thermocable’s ProReact Plus Digital LHD cable is both UL and ULC approved. This approval covers both the low smoke zero halogen outer coat and the optional stainless steel outer braid.

Please contact us directly for a copy of the software.

In order to minimise false alarms and ensure your ProReact Analogue LHD system responds as expected, it is very important to make sure that the chosen control unit setting for selecting the alarm temperature is suitable for use given the typical and maximum application temperatures that are likely to be expected during normal operation in the installed environment.

Please refer to the installation manual for further information on typical and maximum application temperatures.

Simply connect the linear heat detection cable or interface module / control unit into a conventional fire panel or into an addressable loop using an input/output module. Detailed instructions of how to make the connections should be provided within the installation manual of a linear heat detection system.

Water leak detection cable should be firmly attached using self-adhesive U clips or similar. These can be screwed through to ensure the clip does not become loose. When using the detection cable on the floor, ensuring the cable does not have any air gaps under it will give the quickest response to a leak. Any gaps between the surface and the cable decreases the response time and increases the required amount of water needed to trigger an alarm.

If the detection cable is to be run alongside a pipe, tie wraps or equivalent should be used to secure the cable at intervals no greater than 150mm (6″) to prevent sagging.

If digital linear heat detection cable has been exposed to a temperature above its maximum ambient operating temperature or the desired alarm temperature or if analogue linear heat detection cable has been exposed to > 125⁰C, the affected detection cable must be replaced.

We recommend that the affected section of detection cable and 3 metres either side is replaced with new cable and connected to the existing zone using a junction box. Please get in touch if you have any queries on replacing detection cable in an existing system.

Both the ProReact EN Analogue sensor cable and the ProReact EN Analogue Composite Control (PACC) unit can be tested independently. Please refer to the installation manual and the sensor cable testing instruction manual for more information.

The ProH2O Module continuously monitors the detection cable for faults along the length of cable. To test the detection cable will detect a leak either dip the cable into a tray containing a reasonable amount of water or take a piece of conductive wire (less than 22AWG) and touch it between two black cores on adjacent sides of either a red or blue core at some point along the cable.

To verify a piece of cable without powering up the system, disconnect the length of cable from the ProH2O Module and use a multimeter to test for resistance between the two outer most pins on the connector at one end of the detection cable with the end of line plug attached at the other end. In normal conditions the resistance should be approximately 1.8Mohms. Placing a section of the cable into a tray of water should reduce the resistance between the outer most pins to approximately 1Mohms.

In normal operation, removal of the end of line plug should put the module into fault.

Simulating an alarm condition and testing for a fault following one of the methods mentioned above verifies the integrity of the cable along its whole length. The detection cable must be completely dry for a fault condition to be detected.

Please see below the information for the fire and fault outputs:
Fault condition
2x Form C volt-free relay contacts (resistive, common)
Max V – 30Vac or 42.4Vdc
Max Current – 2A
Max Switching Power – 60W, 62.5VA

Fire condition
2x Optoisolated phototransistor output (resistive, common)
Max V – 35Vdc
Max Current – 80mA
Max Power Dissipation – 150mW

Linear heat detection cable is most commonly installed using fixing clips and tie wraps. It is critical that the operating temperature range of the clips used are suitable for the given environment.

Thermocable’s ProReact Accessories are a comprehensive range of metal clips and supports with suitable maximum ambient operating temperatures for any application thus giving our customers piece of mind.

Plastic clips should be avoided as these are likely to have an unsuitable maximum ambient operating temperature.

Functional testing of digital linear heat detection by heating a section of cable up until an alarm is initiated is an effective method but can be costly as the section of cable must be replaced following the test.

Alternatively, it is possible to undertake a test using Thermocable’s ProReact Digital EOL unit with Test Facility (SKU: A1385). This unit allowed a functional test to be carried out on the zone of digital LHD cable to verify normal, trouble and alarm functions of the system by simulating a break in the cable or a overheat condition.

Please get in touch with us if you require further clarification on testing a digital linear heat detection system.

Analogue linear heat detection systems identify fires or overheat conditions by continuously measuring changes in electrical resistance along the detection cable. An alarm is triggered once the resistance along the cable falls below a set threshold.

Digital linear heat detection cable is often referred to as non-resettable as a physical change takes place in the detection cable once the alarm temperature is reached and the cable must be replaced following a fire or overheat condition. It is constructed of two metal core wires that come into contact at a certain temperature and, in doing so, create a short circuit. This triggers a resulting alarm on the interface unit or fire control panel.

Digital linear heat detection cable is often referred to as non-resettable as a physical change takes place in the detection cable once the alarm temperature is reached and the cable must be replaced following a fire or overheat condition. It is constructed of two metal core wires that come into contact at a certain temperature and, in doing so, create a short circuit. This triggers a resulting alarm on the interface unit or fire control panel.

Analogue linear heat detection cable is commonly known as resettable line-type heat detection as the system can be restored following the event of a fire if the detection cable is not exposed to a temperature above 125 ⁰C. Rather than a physical change taking place, the control unit measures for changes in resistance along the entire length of cable. An alarm is triggered once the resistance along the cable falls below a threshold determined by the chosen alarm temperature setting.

Thermocable recommends that the cable is fixed in place using a clip every 0.5 metres – 1 metre (ideally 0.5 metres to avoid any sagging).

Thermocable had to introduce hardware and software modifications to its existing ProReact Digital LHD range in order to meet the requirement of EN54-28. As a result, these two systems are materially different and are not cross-compatible. I.e., you cannot use ProReact Digital LHD cable with a ProReact Digital Sensor Control Unit (DSCU).

An unintended consequence of making these changes is the reduction in maximum zone length per zone of detection cable. This is 1,000 metres per zone for the ProReact EN Digital LHD system. However, please note that two zones of detection cable can be connected to a single ProReact Digital Sensor Control Unit.

Please find the range of settings below per system:

ProReact Analogue = 54⁰C, 64⁰C, 72⁰C, 79⁰C, 86⁰C, 100⁰C

ProReact EN Analogue = Class A1I / A2I (VdS approved), Class BI (VdS approved), 54⁰C, 64⁰C, 72⁰C, 79⁰C, 86⁰C, 100⁰C

(Other Pre-Alarm temperatures also available).

ProReact EN Analogue sensor cable is comprised of four inner core wires.

Two zones of ProReact Digital Linear Heat Detection cable can be connected to a ProReact Digital Interface Monitor Module.

The sensitivity of the ProH2O Professional and Module units is set during manufacture to provide an optimum level of protection against significant leaks which are a threat to mission critical or other sensitive equipment.

As a guideline a minimum of approximately 100ml of standing water on a surface, at least 4mm (0.15″) deep and 150mm (6″) long, in contact with at least 150mm (6″) of detection cable is necessary to trigger an alarm.

It is important to note that when using the leak detection cable underneath a pipe a continuous flow of water at approximately 5l/min will need to be pass over a minimum of 125mm (5″) of cable to trigger an alarm.

The system should be regularly inspected at least once a year to ensure correct operation. This should include visual examination of the control units and detection cable. The detection cable should be clean and free of dust or other contaminants for maximum effectiveness.

Yes, each zone (or “run”) of digital linear heat detection cable should be connected to an end of line unit.

The ProH2O Professional unit incorporates integrated alarm location which will automatically determine the distance along the length of cable to the water leak. The module is designed for simple and straightforward installation and operation.

The installation manual and data sheet are available in English, German, Polish and French. Further languages may be available on request.

There are no restrictions in place for the minimum amount of detection cable installed per zone or system.

Yes, to our knowledge we were the first manufacturer to have a full system (consisting of detection cable, an interface unit and end of line unit) certified according to EN54-28.

Please see below the range of heating cable available (according to length of pipe requiring protection):
Type 1 – Orange – For piping between 5m and 9m
Type 2 – Red – For piping between 9m and 15m
Type 3 – Yellow – For piping between 15m and 25m
Type 4 – Blue – For piping between 25m and 42.5m
Type 5 – Brown – For piping between 42.5m and 60m
Type 6 – Green – For piping between 60m and 92m
Type 7 – Violet – For piping betw

The ProReact Digital Interface Units are IP65 rated and measured as follows:
Height: 180mm x Width: 120mm x Depth: 60.5mm (H7.1in x W4.72in x D2.38in)

Thermocable’s ProReact Digital Interface Monitor Module and the ProReact Digital Sensor Control Unit require a 24V power supply.

This detection cable is available in 100 metre, 200 metre or 500 metre reel lengths as standard. Non-standard lengths can be supplied but will incur a small surcharge. Please note that the maximum available reel length is 500 metres per spool.

Thermocable has referred to the colour coding for heat detectors within NFPA 72 when designing its products. The colour of its ProReact Digital Linear Heat Detection cable is as follows:

Alarm temperature of 79⁰C and below – Red
Alarm temperature between 80⁰C and 121⁰C – White
Alarm temperature between 122⁰C and 162⁰C – Blue
Alarm temperature between 163⁰C and 204⁰C – Red
Alarm temperature between 205⁰C and 259⁰C – Green

An optional black nylon outer coat and / or a stainless steel outer braid can be added to the majority of our detection cables.

A typical system will consist of:

• Detection cable
• An end of line unit (for each zone of detection cable)
• A control unit or interface unit

Other components such as junction boxes, which used for splicing or connecting two lengths of detection cable together, or non-sensing (‘leader’) cable are also available.

This European Standard applies to non-resettable line-type heat detectors consisting of a sensing element using an electrical sensor cable which can be connected to a sensor control unit or either directly or through an interface module to a control and indicating equipment intended for use in fire detection and fire alarm systems installed in and around buildings and civil engineering works.

Linear heat detection is a cable-based type of fire detection. A physical or electronic process occurs within the detection cable and initiates an alarm once the temperature around the cable reaches a certain threshold (i.e. alarm temperature).

The recommended ambient operating temperature range is between -20°C and +50°C (-4°F – +122°F).

The ProMinder controller automatically checks the heating cable for integrity. There are, however, several other tests which can be performed to ensure the system is functioning correctly.

Each ProMinder unit contains a test button which forces the control unit to activate the heater circuits. Holding this button down should briefly activate the primary circuit and then the secondary circuit. This will repeat as long as the button is held down. The current flowing through each heating circuit is checked by the controller when the test button is pressed. If the measured current is outside the cable specification the corresponding fault indicator will light. After 1 to 2 minutes of continuously holding the test button the cable should be noticeably warmer than ambient conditions.

Please find a summary of the compatibility by material below. More information can be supplied on request.
PVC is resistant to ammonia, copper nitrate, fuel oil and diesel fuel
Nylon is resistant to butane, fuel oils, gasoline, methyl ethyl ketone, diesel, ethyl alcohol and ethanol
Polypropylene is resistant to ammonia, copper nitrate, hydrofluoric acid, diesel and acetic acid
Stainless Steel is resistant to ammonia nitrate, , butane, copper nitrate, fuel, gasoline, methyl ethyl ketone, diesel, ethyl alcohol and ethanol

The low smoke zero halogen outer coat has good resistance against ammonia, copper nitrate, hydrofluoric acid and acetic acid.

Please contact us if you have a question on the chemical compatibility of this material.

Both the detection cable and control unit can operate continuously between -20⁰C and + 70⁰C.

Independent – This is when the interface unit is used as a two zone system. When a fault or overheat condition occurs on a Digital LHD zone, the corresponding fault or alarm output respectively is triggered. The two zones operate independently and both sets of outputs should be connected to a fire alarm control panel. If the zone is not required leave the 3.6kohm resistor in the zone input terminals as supplied. In this mode, the two zones can either contain identical rated temperature Digital LHD cables or two different rated temperature Digital LHD cables.

Interlock – this mode is for applications which require a fail-safe guarantee that an alarm is only triggered when an overheat condition has been detected. This mode may also be known as coincidence detection. In this case, the same rated temperature Digital LHD cable should be attached to both zones of the interface unit. The alarm output is only activated when both Digital LHD cables trigger an alarm due to an overheat condition. If one Digital LHD cable zone input registers an alarm but the second does not, the alarm output will not be activated. This is to prevent an alarm if a mechanical or other issue has triggered one Digital LHD cable and not an overheat condition.

UL approval has been granted for two versions of control unit. One is a self-contained unit or, for finer control, a version requiring a laptop prevents uninvited system access via a software programme.

Thermocable supports the Fire Industry Association’s guidance on the life expectancy of fire detection and alarm systems providing that its products have been installed as per the installation manual, are not exposed to temperatures outside of their ambient operating range and are tested regularly. The FIA states it is considered that heat detectors would not be expected to deteriorate even over extended periods well in excess of 10 years.

ProReact VHT Digital Linear Heat Detection cable can continuously operate in temperatures up to 170⁰C without deterring its performance.

Each zone of ProReact Digital Linear Heat Detection cable can contain up to 3,000 metres. Two zones of detection cable can be connected into a ProReact Digital Interface Monitor Module allowing the maximum length of detection cable per system to be up to 6,000 metres.

Between 30 metres and 305 metres of ProH2O Water Leak Detection cable can be connected to a ProH2O Professional unit.

Alternatively, up to 1,000 metres of ProH2O Water Leak Detection cable can be connected to a ProH2O Module unit.

Thermocable’s analogue linear heat detection cable and end of line units can continuously operate in temperatures as low as -40⁰C. The control or interface units typically have a minimum ambient operating temperature of 0⁰C.

Up to 500 metres of Thermocable’s ProReact EN Analogue sensor cable can be connected to a ProReact EN Analogue Composite Control (PACC) unit.
For nearly all installations, the mandatory minimum zone length is 30 metres. However, the minimum zone length is increased to 50 metres for the Class AI1 / AI2 alarm setting.

The minimum length of ProAlert detection cable per zone is 50 metres and the maximum length is 2,000 metres. Furthermore, each ProAlert control unit can monitor up to two zones of ProAlert detection cable.

Cable zone lengths can vary from 30 metres to 500 metres in length.

There is no minimum zone length for this linear heat detection cable.

All Thermocable’s ProReact Digital Linear Heat Detection Cable has a minimum ambient operating temperature of -40⁰C (-40⁰F) and can operate between 0-100% relative humidity.
Please find the recommended maximum ambient operating temperatures below:

Operating Voltage Range – 0-30Vac, 0-42Vdc
Resistance – Approx. 100Ω/km (30.4Ω/kft) per leg
Velocity of Propagation – Approx. 55%
Capacitance – 88 – 150pF/m
Inductance – 540 – 1050nH/m

Thermocable typically supplies its ProReact Digital Linear Heat Detection cable on its standard reel lengths of 100m, 200, 500m or 1,000m where available. Alternatively, non-standard lengths can be supplied at an additional cost on request.

All ProReact EN Analogue sensor cable is manufactured on-site at Thermocable’s factory in Bradford, West Yorkshire. The standard reel lengths available are 100 metres, 250 metres and 500 metres. Non-standard reels can be supplied at a surcharge if required.

Another key advantage of using linear heat detection systems is that the ongoing testing and maintenance is hassle free and cost friendly. Thermocable recommends that a linear heat detection system is tested once a year following installation to ensure it is operating as expected.

There are now sophisticated methods of testing a linear heat detection system whereas previously users tested systems by simply imitating a fire by heating up a section of detection cable. Whilst this still an effective test method, it is a costly exercise as the section of cable must be replaced following a test. Testing is now frequently incorporated into the design and operation of the end of line units and interface modules or control units. Instructions on how to test will be enclosed in the installation manual of a linear heat detection system.

Please get in touch with us if you require further clarification on testing or maintenance.

The ProAlert control unit requires either a 3 year li-ion battery or a 18-24VDC power supply. Please note, the battery can be used as a back up power supply if needed.

Thermocable’s ProAlert detection cable is available in pre-terminated lengths of 5 metres, 10 metres and 25 metres.

The following pre-terminated lengths of water leak detection cable are available:

• 3.75m (12ft)
• 7.5m (25ft)
• 15m (50ft)
• 30m (100ft)
• 50m (164ft)
• 100m (328ft)

Custom lengths are also available on request but incur a small surcharge.

Please contact us directly and we can provide this free of charge.

One of the main benefits of linear heat detection cable is its versatility. It can be installed in both indoor and outdoor environments and in hazardous areas if required. Please contact Thermocable if you have any installation or design-related questions.

ProReact VHT Digital Linear Heat Detection cable is a specialist detector designed for environments in which standard linear heat detection or other types of detectors would be unsuitable. Such applications include vehicle engine bays, commercial kitchens and manufacturing or industrial plants.

The outer silicone jacket on the detection cable has good or better resistance to the following chemicals: ammonia, copper nitrate, fuel, gasoline, kerosene, diesel and acetic acid.

The ProReact EN Digital LHD cable (various alarm temperatures available), the ProReact Digital Sensor Control Unit (DSCU) and the ProReact Digital End of Line Unit (EOLU) are all listed as components on the system approval certificate.

Please find below the list of components certified according to UL521:

• ProReact Analogue LHD cable – PVC
• ProReact Analogue LHD Cable – Nylon
• ProReact Analogue Control Unit – Self-Programmable inc. EOL unit
• ProReact Analogue Control Unit – Laptop-Programmable inc. EOL unit

They provide a technical basis to assess the performance of construction products and they enable manufacturers to draw up declarations of performance and affix CE and UKCA marking. Products that are resistant to fire or react to fire fall under the definition of construction products in the European Union.

Low smoke zero halogen cables are being increasingly specified and used in environments where smoke and harmful emissions released in the event of a fire could endanger human life. ProReact Plus Digital LHD cable is a low smoke zero halogen, UV stable and hydrocarbon resistant alternative to traditional digital linear heat detection cable.