F/A Detector For Transformer Area

I usually use thermal detectors and smoke detectors together. Depending on the size of the transformer, at least 2, and as many as 8, of each type are used. Any single detector of either type can cause an alarm, but it takes at least one thermal AND one smoke detector to activate the fire suppression system and deenergize the transformer.

NOTE: In some very hot areas (such as near a combustion turbine), the smoke detectors will overheat and fail. In that case I use a second type of thermal detector in place of the smoke detectors. This still provides confirmation of fire, as 2 different sensing technologies (infrared and expanding fluid) are used.