AC vs DC wiring color matter?

[Rich585]

I am confused on wiring conventions.

Residential AC wiring has white wire neutral, black wire 120vac, bare copper for ground.

DC wiring has black wire negative, red for positive.

What I am confused is if you have a small solar system (dc) and have a 2000+watt inverter that allows you to run power to a small panel, what wiring convention is considered proper?

Would it not be confusing to have a black wire DC negative and AC “hot” in the same panel?

I am thinking towards wiring in a DIY camper or garage for example.

What is proper color coding or does it not matter as long as it is consistent?

thanks

 

[HRTKD]

The wire colors in my RV trailer are all over the place on the DC side. But on the AC side I think it is consistent and follows the colors you posted, though I would call the black wire "hot". A green wire can also be ground.

 

[Rich585]

Thanks

I find the electrical code books contradict as I think they were written for either AC or DC but not both. You are correct, green is also ground.

My main concern is is getting shocked from a black 120ac wire thinking it is DC negative.

I want to understand what proper rules are in case I needed to get an electrical inspection and/or for insurance purposes.

 

[wholybee]

Yes, that is correct, and confusing, and dangerous. To make is safer, AC wires and DC wires should never be run together, or in the same conduit. Where they by necessity are near each other, you can us a spiral wire loom around the AC wires.

You could also adopt ABYC (used on boats) colors, where DC Negative is yellow.

 

[HRTKD]

I haven't dug into the AC side of things too much in my RV. I have pulled the main distribution panel out a couple times. I think every AC line in there is Romex. Three wires in a sheath. I don't have any AC wires that are on their own without being traced back to Romex within a few inches.

 

[Rich585]

Thanks - good suggestions.

1) Keep AC separate (different wire) or wire loomed
2) Yellow for negative, need to read up on that. I did notice on Amazon Ancor marine wire had red/black and red/yellow wire pairs but did realize it is a another DC standard.

Thanks for quick responses. I have a lot learn.

 

[rickst29]

Many, many RV's have had their "12v" systems wired in black (+12v) and white (12v grounding neutral, which should actually be interconnected with the RV's green safety grounding wire for 120v).

Any inspector will understand this, and will also understand that some large wires of the "12v" system (e.g., the supply wires into your large Inverter) are not sold in a variety of different colors. They're all big (2/0, or even 4/0) and black. If you want to impress the inspector, a lot, then you can mark these wires with red electrical tape on the +12v wires. I always mark the ends of my large "12v" wires with red shrink-wrap tape, at the lugs.

But the inspectors will not be that concerned with the colors of 12v wires. What they WILL want to see is that every "+12v" hot wire goes through a fuse, the 12v grounding is firmly connected to the frame (as well as the on-board battery "-"), and that 12v grounding bus also has a good connection to the 120v system safety ground bus for green and bare wires. On 120v, they will want to see circuit breakers for everything, both in (30A/50A) and out. They will also want to see that every "normal" socket is also connected through a GFCI or AFCI device (an "upstream GFCI/AFCI socket, or an actual AFCI breaker). Only the Air Conditioner gets a connection without a GFCI/AFCI device.

And of course, they will be looking for frayed insulation and especially for terminals which aren't tight. Loose terminals often develop in travel trailers, do to vibration in road travel - and they should all be re-tightened as a part of annual maintenance.

 

[Rich585]

Thanks great advice on fusing. I did learn that one by melting wires unfortunately but I agree, every wire needs fusing on based on wire gauge. Fuse on battery, then smaller fuses on each circuit from fuse terminal block (12 v)

Did not consider GFCI requirements as just used to plugging into smaller inverters directly but once it becomes a permanent install I see higher requirements. That is good to know.
I should look into GFCI power bars for my current potable inverter when camping.