Fire Alarm Renovation

[raranari]

Hey everyone, I’m currently working on a K-12 school renovation where the scope is the replacement of the existing fire alarm system. The district requires the existing fire alarm system to remain fully operational until the new system is installed and commissioned and after that the existing system will be removed.

The issue I’m running into is that the existing life safety panels are completely full. I’m trying to understand whether it is code compliant or even possible to tap the existing branch circuits that currently serve the existing FACP and power supplies (NAC, FATCs, boosters, etc) to temporarily power both the existing and the new fire alarm systems simultaneously.

I understand that fire alarm equipment typically doesn't draw that much power, but I want to confirm whether this approach is permitted by NEC or if I would have to start checking other options.

Has anyone dealt with a similar situation in an occupied school, and if so, what was the your approach?

 

[Boingo1972]

At a minimum, you would need to know which wire was used for the system. Generally they are FPLR (fire alarm) cables that hold a fire resistive rating since it's an emergency circuit. Depending on what type and which UL FHIT document controlled it when it was installed, you may or may not be allowed to have splices in it. Also since manufacturers of these wires often improve their systems (thus getting a new FHIT document from UL) the stuff installed may be obsolete now and not supported (not allowing splicing). Granted you can splice it if it's within a protected space, but a lot of research would be necessary to know if that is the case.

 

[ron]

As long as there is sufficient capacity in the 120V circuits, feel free to tap. There is no code limitation. Ensure they make final permanent connections at the end of the project.

 

[roger]

At a minimum, you would need to know which wire was used for the system. Generally they are FPLR (fire alarm) cables

The OP is not concerned with the FA cables he is asking about the 120V branch circuits which would most likely be THWN in EMT.

What we have done in the past was have our FA contractor complete the new system and we would temporarily power it with the existing branch circuits in parallel with the old system. After AHJ (State or Local Fire Marshal) approval we would disconnect the old system. The Monitoring company would be notified that the systems would show trouble during these switch overs.