Notifire CPU2 -640 ( NFS2-640) INVERP” on the panel

Fire Alarm Help
1

hello

i hope you all having a great day.

, could you please help me with an issue I’m experiencing with Notifire ( NFS2-640 ) ?

I have a Notifier CPU2-640 with 2 SLC loops.

The problem is that the panel intermittently loses some devices, triggering a trouble signal that appears as “INVERP” on the panel. Then, the trouble clears itself, and the system returns to normal.

The affected devices are randomly selected and are located far apart from each other. The panel remains normal for a day or two before the issue starts happening again. ( sometime less than That)

Sometimes, a false alarm signal is triggered from a device (e.g., pull station, heat detector, smoke detector, or monitor module), which dispatches the fire department.

I have already replaced the panel, but the issue persists.

Im thinking that the SLC voltage might be fluctuating lower than it should be at some point , im reading on the panel (14.8V–13.6V).

We take over this new account and now having this issue ,

The issue always happens on loop 1 ( from the panel ) , loop 2 no problem

Do you know if there’s a anyway to increase the SLC voltage slightly, perhaps to 15V–18V, to see if that resolves the issue?

Please Let me know your thoughts. I appreciate your help!

2

If you replaced the panel already, you should also replace the lem-320. You said the issue is only happening on loop1 but they are integrated and that would be an easy fix.
Do you have isolation modules? If you do I move 1 at a time from loop 1 to loop 2 if you have room on loop 2 and see if the issue moves, then you know its a device on that isolation module.
If not, i would be suspect of any high humidity areas or areas with potential water damage. RTUs, pump rooms, parking garages…

1 Like
3

What gauge of wire is coming from loop one? If it’s too small the devices may be too far away to communicate reliably.