Linear Heat Detection System - Control Unit LWM1

Linear Heat Detection System - Alarmline Control Unit LWM1 - Kidde 22-11810-050
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LWM1 - Linear Heat Detection System - Alarmline Control Unit - KIDDE

The Alarmline LWM-1 Linear Heat Detection System allows early detection of fire or overheating. It is especially suited for confined areas or harsh environments where adverse ambient conditions cause other detection devices to be unreliable or difficult to use.
The system consists of two components: the sensor cable and the Alarmline control unit LWM-1.

The control unit reports temperature differences by the permanent supervision of the resistance of the sensor cable. The response threshold Max-alarm can be adjusted with a 16-step dip-switch. The Maxalarm is triggered if the static alarm temperature of the sensor cable is reached or exceeded. Two 16 step dip-switches are available for the adjustment of the differential alarm: Diff-time and Diff-alarm. Difftime changes the integration time of the ambient temperature; the shorter the time interval, the lesser sensitive the system responses.
Diff-alarm changes the temperature range, which delivers a constant temperature/measurement-correlation.
The higher the Diff-alarm value is chosen, the higher the possible alarm temperature. Individual LED’s for “Power“, “Max-alarm“, “Diff-alarm“ and “Fault“ indicate the actual status of the system.
Two test buttons within the control unit allow for an electrical check of the system for alarm and fault. All alarm and fault messages are latched in the control unit. A reset can be generated either by an interruption of the power supply or an activation of the External-reset input. The electronic PCB of the control unit is housed in a plastic housing (ABS: Protection class IP 65). Connections to supervising fire panels can be made via potential-free relay contacts (2 A, 30 V) for alarms and fault.


• 3840 application specific settings
• Early fire detection (heat detector classes A1, A2, B, C)
• VdS approved, based on standard EN 54-5:2000
• Low probability of nuisance alarms even in rough environments
• Low space requirement for sensor cable
• Easy installation of sensor cable
• High chemical and/or mechanical resistance using special coated sensor cables
• Control unit may be installed up to 500 m remotely from sensor
• Easy maintenance of the system
• Constant sensitivity over entire length of sensor cable
• Sensor length up to 300 m
• Resistant to mechanical and chemical influences, corrosion, humidity and dust
• Easy to install, economic, lowmaintenance, simple commissioning
• Suitable for use in EX classified areas
• VdS approved, No.: G 20 50 66

Specific application advantages

• Car parks: Early recognition of fires despite exhaust gases, dirt and humidity
• Recycling plants: No false alarms due to dust and dirt, no interruption of operation during maintenance
• High-voltage installations: Installation of the control unit in safe area, no influence by interfering electromagnetic fields
• Cold stores: No false alarms or faults due to icing-up of the sensor cable, low maintenance costs
• Raised floor: Installation possible under tight space conditions
• Industrial manufacturing: Simple maintenance even under high ceilings and/or large overhead cranes; sensor resistive against contamination
• Conveyor belts: Early recognition of fires also in changing climatic conditions, dirt and humidity
• Escalators: Continuous detection along the entire sensor, no interruption of operation during maintenance
• Tunnel: Low probability to false alarms despite exhaust gases, dirt and humidity, installation of the control unit outside of the traffic region

Reference : 22-11810-050