Bosch FAH-425-T-R Heat Detector with Rotary Switches - 6 Sensitivity Classes

With the detector types FAH-425-T-R, it is possible to set one of the sensitivity classes listed above in line with planning. In the sensitivity classes A1, A2S and BS, the FAH-425-T-R is operated purely as a thermal maximum detector.

Key features

• In this case, the detector does not activate at below 54 `b0C in class A2S,
• and not below 69 `b0C in class BS.
• The sensitivity classes A2S and BS are therefore particularly suitable for applications where higher temperature rates-of-rise occur over a longer period, e.g. in kitchens or boiler rooms.
• The sensitivity classes A1R, A2R and BR indicate that the thermal differential unit is active in addition to the thermal maximum unit.
• These sensitivity classes are especially well-suited for use in unheated buildings where the ambient temperature can vary greatly but high temperature rates-of-rise do not last long.
• The thermal differential unit enables class A1R/A2R detectors to respond at T<54 `b0C and class
• BR detectors at T<69 `b0C.
• The selection of the sensitivity class also depends on the installation height of the detector.
• Furthermore, the expected application temperature must be taken into consideration.