High Power Consumption for Mains Wired Interconnected Domestic Alarms

[gmerry]

Hi all, I have an interconnected mains alarm system with CO monitor (rechargeable lithium battery), Heat Sensor, two off Optical Smoke sensor and 1 off Ionisation Smoke detector. There is a hard wired test/silence/locate switch.

 

All electrical tests show more than 200 Mohms between each of the 3 conductors (Line, Neutral, Interconnect, plus earth) so can rule out wiring fault. In operation, there is zero DC or AC voltage on the interconnect so nothing funny their. The system is wired in Fire Alarm cable (Prysmian FP cable)

 

The power consumption of the 5 wired inter connected alarms is 60 watts. If all the alarms are removed from their bases, the power consumed is zero. As soon as the 1st alarm is connected, the consumption goes up to 35 watts, then as each one is added, it makes the 60watts

 

Has anyone else seen a domestic system with such a high consumption (manufacturer is telling me that each individual alarm should consume less than 1watt)?

 

many thanks

[Tom Sutton]

This question would be best suited for  a fire alarm engineer forum http://firealarmengineers.com/forum/.