Powering Elk expander zones


Senior Member
I have my main board in a cabinet near the HAPC in my equipment closet, and a 2nd cabinet with 3 16z expander cards in the basement where the wiring for sensors is all run.

I have a variety of 4-wire sensors. Am I supposed to draw power for all 16 sensors through that little itty bitty 12V + / - port on the expander cards? Or should I be getting that Elk-P412 Power supply for zone power?

I'm powering 4 zones right now, and i'm already cramming the crap out of that little port.
If you are running Smokes from the 2nd Cabinet they should be getting the power from the Smoke Power terminals on the M1 everything else should get it's power from the M1 AUX terminals. Just run an 18/4 between the cabinets.
Not following you - are you saying that for smoke's, i should run 1 pair of wires to the 2nd cabinet/expander location for zone control, and the main cabinet for power?

I have 3 expanders hooked up to the bus, which in turn is hooked up to the M1 main board's aux terminals. I was drawing power for the 4-5 sensors I've currently got off those aux terminals.
I believe he is saying smoke power needs to comes from the panels SAUX terminals because it switches power which the smokes need to reset, etc. I guess my suggestion would be if possible to run the smoke wires to the M1 if possible (as long as you haven't run them yet) instead of the remote cabinet. If you are running 2 wire smokes they need to be on zone16 in the panel anyway. If running 4 wire smokes to a remote expander then he is saying to run an 18GA wire for power from the M1 to your remote location. I am guessing he suggested 4 conductor so you can pull both SAUX (switched power) for smokes and VAUX (constant power) to the remote.

While you do need the SAUX for wherever you terminate the 4 wire smokes, I would probably suggest a PD9 and appropriate adapter (or the kit) wherever you have an expander with a lot of powered zone devices. As long as you don't exceed the current limits, which you can view total current used at the keypad, you can use the VAUX, but the PD9 may be cleaner and eliminate the extra 18GA power runs, albeit more expensive - especially when you add battery backup to it (assuming you want your powered devices like PIRs to work during power outage).

I think the above is technically accurate but Electron and some others have a PD9 and I'm sure can verify this.
Sorry for the lack of discription I was 99.9% a sleep when I wrote it. If it is helpfull I can create a drawing for you tonight when I get home.
power needs to comes from the panels SAUX terminals because it switches power which the smokes need to reset, etc.
Eh, oops. Totally phased on that.

I don't want to run the smokes to the main panel as I have it in the media closet next to the HAPC, and I'd like to keep as few wires running into it as possible. However, running another 18/2 or 18/4 is certainly easy.

I think i'll also get that PD9 as you suggest, as it definitely sounds like a clean solution for the VAUX.