Small plug in type transformers
Is Un acceptable in
Commercial Fire Systems without protection?
And other bad AC Power Practices
Many of the modern Combination Commercial Fire and Burglary Systems available on the market today I.e. Napco, Radionics /Bosch , DSC, Morse/Optex etc. come with a small plug in transformer which is designed for use only when the panel is being used for Burglary Only.
To use that same transformer to power the panel when it is being used for Commercial
Fire service it has to be No # 1 sized correctly for the load expected to be drawn thru it. And no # 2 it has to be UL commercial Listed and No # 3 it has to be physically protected from damage and the wire from it to the panel as well.
To meet the physical Protection requirements of a commercial system using a plug in transformer there is a special steel enclosure kit, which is to be purchased separately
Which is vented and totally covers the transformer and outlet , as you can see in the picture a proper transformer set up with one open on left and one closed on right
I was actually shocked to see this out of 98% of all combos I see done wrong this panel was done correctly
A piece of electrical conduit is then attached from the transformer enclosure to the combo panel there by protecting the power to the panel. Rarely have I ever seen this protective kit used were it was required. Ademco got around this problem by supplying the proper
Sized transformer and enclosure. With there panels. Which I still see being put in wrong.
It comes back directly on the backs of those AHJ’s who refuse to take seriously the Fire alarm Inspections they are doing. And refuse to get there training upgraded.
The AC power supply to a life safety system is one of the pieces to a total fire System
Additionally the circuit supplying the outlet the transformer is plugged into is to be dedicated just for that outlet and the breaker is to be marked with a red marking to prevent it being accidently shut off and the breaker panel is to be clearly marked which breaker supply’s the Fire panel this also goes for direct wired Fire panels.
Plus in the Fire panel it is to be noted which breaker is supplying it.
This brings up another dangerous situation I have been finding, involving the AC power coming into new fire panels which are replacing older AC only bell and pull station panels. Typically the installer pulls the old panel out puts the new panel in place and gets his AC power from the old switch or breaker supplying the old AC system which is
Acceptable, but they then hook up a 14# gauge wire to the 30 amp fuse or breaker which is an overload situation and fire or accident waiting to happen ,when they should have changed the fuse to 15 amps. In the old days they took the AC power supplying Fire Panels and pulled it directly from the services main lugs this is still legal today but all NEC rules have to be followed , which they are not most of the time.
We keep coming back to the same question who is training who.