Notifier nac 2

Have a notifier nfw2-100 panel at a ice hockey rink. Keep getting nac 2 open troubles… find broken h/s and replace. But a few times now get a nac 2 open, go around trying to troubleshoot and cant find an issue, but if i pull the nac clips off on the panel (wired class A ) and place right back on it clears for awhile comes back randomly few days later maybe even weeks. Any ideas, possible build up of some sort?

Maybee a bad end of line resistor somewhere in the circut?

There is only one end of line resistor in a notification circuit. This one is said to be a class A circuit so the the EOLR is in the panel.



There could be a loose connection in a notification appliance or junction box. There are some checks that can be made. With the panel in standby check the voltage between B+/B- and A+/A-. One of those is the beginning of the circuit and the other is the end of the circuit. The voltage should be the same within a few tenths of a volt. More than that could mean a bad connection. You can also compare those voltages with the NAC that is not giving any troubles.



With all 4 wires disconnected check the resistance between B+/A+ and B-/A-. Those resistances should be the same and typically should be below 3 ohms. Any difference more than a few % would indicate a bad connection in the circuit.



There could be a problem in the panel itself. You did not indicate what kind of appliances are connected to NAC 2. If possible switch the wiring between NAC1 and NAC2. If one is horns and the other is strobes a program change is probably required. If the troubles move to NAC1, the problem is in the field wiring. If the troubles stay on NAC2, the panel is suspect.



Good luck.

Depending on how many devices there are… Couldn’t you check the resistance of each point on the NAC til it increases or it goes blank which is where the issue would be right?





And nice to see another Sprague! :smiley: