This is the 3rd. time we are getting a call from a customer with an Access Control System that fails when the panel freezes and does not respond to any card presented on the reader in the main entrance. The freezing is due to spikes/undervoltages/electrical events when it rains a lot. The customer says his central surge suppressor (the one that sits between the electrical company and the private building electrical circuit) is working well. But still the panel freezes. The only way for the customer to get inside his office was through a garage door (which is NOT wired to the Access Control System) to reach the electrical circuit breakers panel and turn off the mains 120V-AC electricity for all the outlets in the building.
We've installed some relatively cheap EMERGENCY DOOR RELEASERS besides each door inside that work simply upon breaking the very thin glass it comes with, but of course they only work is someone is already inside, and also would be very vulnerable to tampering from strangers if they are installed outdoors facing the street.
Coincidentally, today I saw a FIRE SWITCH installed on a building tower that is embedded inside a granite wall. Do you guys think that this device (which really is for a fire prevention system) can work installed outside and wired in the same circuit as the electromagnetic lock as to mechanically cut the electrical supply to the magnetic lock and therefore opening the door ?? (it seems the glass circle can only be broken if 1000 kg is applied and also it seems to me that it would be less eye catchy for any strangers passing by the street).
I am not sure what the standard codes (if NFPA mentions something or not) are for Access Control Systems release devices as a last resorts if the panel-controller fails and all the doors are locked from the outside and one has to go the electrical circuit-breakers panel as a non-elegant solution for resetting the system from scratch. Any comments ? Thanks.