I have a 4009-9001 NAC Extender that came with my 4020 that I am looking to wire back to the panel, but am a little confused on how it’s tripped by the panel. According to the wiring diagram, the positive of one of the panel’s NAC circuits lands in TB3-3 of the 4009’s signal board, and apparently there is a 0V common that comes from the panel and lands in TB1-3 of the 4009’s power supply board. The part I don’t understand is the last part - I’ve seen other 4009s that do not have any field wiring landing in TB1-3, so I am not 100% certain on where this 0V connection is supposed to go. I am also not sure if that 0V connection comes from the -24V auxiliary power in the panel or the -24V of the triggering NAC circuit. Does anyone know how to wire these 4009s? I just want to make sure I wire this correctly so I don’t damage anything.
To clarify, this is an older conventional 4009 from the 1990s (and not the newer addressable IDNet version).
It looks like TB-3 is for the extender alarm and trouble contacts. The trigger for NAC circuits 1 & 2 are terminals 1 & 2 on TB-1 and for NACs 3 & 4 terminals 1 & 2 on TB-2.
According to this (^) diagram on the inside of the door, the wiring from the control panel lands in TB3-3 of the signal board, and TB1-1 of the power supply board. It looks like the (+) of the triggering NAC lands in TB3-3, and the OV (-) goes in TB1-1. I’m guessing that 0V is coming from the panel’s negative 24V non-resetable power output. The last part is what isn’t clear to me, I don’t remember any field wiring landing in these terminals when I removed it from the wall, just the wires you see in the picture (which go to the signal board).
There is also a resistor harness that runs between TB1-3 (0V) and TB3-3. I have no idea what this resistor does, but it appears to be a factory Simplex part.
