GMA-VM-FMS Remote alarm system

Monitors district-heating manhole facilities and technical rooms:
detects heat build-up and fire

For monitoring 2 to ≥ 12 signal lines over distances up to 80 km
based on DIN VDE 0833-1, -3, -4

Application: for monitoring district-heating manhole facilities & technical rooms

  • Immediately after the set temperature is reached (57°C, 68°C or 79°C) the thermobulb, which functions as a signal generator (e.g. in sprinkler system), bursts inside the signal generator casing, thereby activating the compression spring. The spring expands and activates the push-pull signal transmitter, which passes the mechanical signal on to the sensor.
  • After the heat has been dissipated and the whole signal generator (casing, compression spring and thermobulb) has been replaced, the sensor can be used again. In the event of fire, the sensor and the push-pull signal transmitter must be replaced too.


Particular features:

  • Various states, e.g. opening, heat build-up, water level etc. can be monitored simultaneously, by setting up the appropriate EMA-VM and GMA-VM remote alarm systems in series. If a GMA-VM is triggered at a temperature range < 80°C, the respective remote alarm can be re-set to alert within 3 minutes after the cause has been removed and the signal generator replaced.
  • When several remote alarms are in use, the precise location of the alarm for water, heat/fire or unauthorised entry is made possible if a dead-zone box (with dead-zone fibres) is utilised.

Components - exemplified in the monitoring of district-heating manholes

Sensor | Remote alarm system (long-duration)

Hazard alarm (shown here with a TO dead-zone box)

Signal generator




 Art. No.


 VM cable (connection to a distribution module)

 49.04 GMA-VM-TO

 (1 x GMA sensor + TO dead-zone box)



 50.29 GS-FMS*

 Signal generator with signal transmitter
  orange:  57°C – 70°C
  red:       68°C – 95°C
  yellow:   79°C – 105°C)


 Protective sensor casing (shown hiere without lid: for max.
 2 sensors [2a] or 1 sensor [2a] and 1 dead-zone box)


 EMA-VM sensor.




 Adjustable attachment ring (for attaching the push-pull signal
 transmitter [5].


 Baseplate for the protective casing


 Clamp Ø 10 mm for attaching the signal transmitter [5] and
 VM cable [1]


 Push-pull signal transmitter (connected to the signal generator [6])


 Signal generator


 Metal casing


 Signal generator: glass thermobulb


 Signal generator: compression spring



 Signal generator: lid


Wolf GmbH

Zazenhäuser Straße 52
D - 70437 Stuttgart

Tel.:  +49 (0)711 87 39 41
Fax.: +49 (0)711 87 12 30

Email: Service(at)