Major Failure of Siemens MXL and FP-11 Question

We have a Siemens MXL and had a planned building shutdown over the weekend by the utility company. 9 hours later…When power was restored we experienced several intermittent alarms and lost 60 of the 400 FP11 detectors, two pull stations, and 4 TRIs. They would no longer respond…even to the programmer. Our Fire Alarm panel company determined the motherboard was bad and replaced it with a used one (New…no longer supported or available) and now we are also replacing all the failed devices. This incident has cost us north of $15k. 5 other buildings were involved in this shutdown but none of the others experienced any damage. The fire panel is located in the basement of a four story building. A majority of the failed detectors were in the basement and were less effected the further away from the panel on other floors.

My Questions: Has anybody else experienced this type of failure? What would cause so much damage? And how do I prevent a future loss?

So far we put a surge suppressor on the line power side of the panel but I suspect that maybe the failure may have come from downstream(?)

Any input appreciated.

I’d consider replacing the existing MXL system with an entirely new fire alarm system, like say a Notifier NFS-320.

you can migrate the system to a Siemens XLS and leave all your field devices in place, easily the most cost effective solution.

Sounds like you had a power surge on your SLC circuit somewhere, not sure how though.