I am wiring a septic control/alarm box to a subpanel. They are on the same post, so the wire run is through a short stretch of 3/4" flex conduit.
There are two circuits required: a 240V for the pump and 120V for the control/alarm system. I'm using 12 AWG wire, as follows:
- hot to alarm
- neutral to alarm
- hot 1 to pump
- hot 2 to pump
What does code say about coloring and grouping of these wires? What about best practices, beyond code?
My Current approach
I'm currently using:
- a 12/2 G cable.
- Black is alarm hot;
- white is alarm neutral.
- Bare is ground (duh).
- a black wire is pump hot 1
- a white wire with red tape at both ends is hot 2
That seems confusing, and I'm not sure if it's quite to code. How can I improve it?
Since it's a short run, I really don't mind buying new colored wire by the foot and redoing all of this.
I have a bit of 12/3 G cable that I considered using like this:
- 12/3 G cable
- black is pump hot 1
- red is pump hot 2
- bare is ground (duh)
- white is neutral to alarm (remember, pump has no neutral)
- single black conductor to alarm
I rejected this because I didn't like the idea of the control box's neutral being in the cable with the pump's conductors - more confusion.
My neighbor's control/alarm box
For comparison, here's my neighbor's control alarm/box, although it uses a 120V pump, so the white wire really is a neutral. (Click for full-sized image).