Run DC negative wire through switch box?

[RNWilson]

I want to wire a simple low voltage cabin light controlled by a switch in a location which is difficult to run wires. Is it considered acceptable to run just the positive wire from the breaker to the switch and then on to the light and run the negative wire on separate path directly from the breaker to the light? In other words do the positive and negative wires need to be kept together as in house wiring? This would not only be easier for me but it would also save a bit of wire since the switch is farther away from the breaker than the light is. Please accept my apologies if this is already been covered somewhere in the forum but I could not find it. Thank you!

[Tomodore]

The point of running ac power wires together has to do with canceling the magnetic field caused by current flow on a single wire. The field for 12v dc to a light wouldn’t be an issue in my opinion. I don’t know what ABYC says on the subject.

[dougweibel]

This sounds like a maintainability issue. Electrically it does not matter if the wires are separated. Years down the road will you, or a subsequent owner, be able to figure out where the wires are if they are separated?

[Wotname]

Originally Posted by RNWilson

I want to wire a simple low voltage cabin light controlled by a switch in a location which is difficult to run wires. Is it considered acceptable to run just the positive wire from the breaker to the switch and then on to the light and run the negative wire on separate path directly from the breaker to the light? In other words do the positive and negative wires need to be kept together as in house wiring? This would not only be easier for me but it would also save a bit of wire since the switch is farther away from the breaker than the light is. Please accept my apologies if this is already been covered somewhere in the forum but I could not find it. Thank you!

Perfectly acceptable!

However don't run a single (pos or neg) conductor close to your magnetic compass or autopilot heading sensor etc.

[boatpoker]

Originally Posted by RNWilson

Is it considered acceptable to run just the positive wire from the breaker to the switch and then on to the light and run the negative wire on separate path directly from the breaker to the light?

The negative does not go toa breaker, it goes to a negative bus.

If LED lights be sure of polarity before you cut wires to length as most LED's are polarity sensitive.

[boatpoker]

Originally Posted by RNWilson

Is it considered acceptable to run just the positive wire from the breaker to the switch and then on to the light and run the negative wire on separate path directly from the breaker to the light?

The negative does not go to a breaker, it goes to a negative bus.

If LED lights be sure of polarity before you cut wires.

[RNWilson]

Originally Posted by boatpoker

The negative does not go toa breaker, it goes to a negative bus.

If LED lights be sure of polarity before you cut wires to length as most LED's are polarity sensitive.

Oh yes of course you're right! I should have said the negative goes to the negative bus bar. My bus bars are right beside the breaker box.

[Flatswing]

Better quality LED’s such as Dr. LED & Marine beam suppliers to name 2, are not usually polarity sensitive (also don’t affect VHF/AIS) though pricier.

[RNWilson]

Thank you all for your comments. I'll run the wires separately to make it easier and label the wires for clarity in the future.

[sinnerman]

I bought an EPSON wire label printer and heat shrink tubing labels to mark the wires. It is added work, and the heat shrink label cartridges are not cheap, but pays off in the end.
I use a heat gun to shrink the labels.

Printer: https://www.ebay.com/itm/Epson-LW-PX...4AAOSw-QBb~vg4

[RNWilson]

Originally Posted by sinnerman

I bought an EPSON wire label printer and heat shrink tubing labels to mark the wires. It is added work, and the heat shrink label cartridges are not cheap, but pays off in the end.
I use a heat gun to shrink the labels.

Printer: https://www.ebay.com/itm/Epson-LW-PX...4AAOSw-QBb~vg4

Thanks I'll check it out!

[Dougtiff]

With LED'S, the amp draw is so low, you can run two conductor wire, that is not any larger than wire for a incandescent light, neater and less work.

[Redline452]

Suggestion: do use the appropriate colour code for the wires - I've seen too many cases where someone "saved" by using a larger spool of a single colour for numerous things, and or for both (!) polarities. Red tape (or better, shrink-wrap) on a black wire sort of indicates positive, but only at the ends, and not as well as using red the entire run. Can avoid expensive mistakes later.

[RNWilson]

Originally Posted by Redline452

Suggestion: do use the appropriate colour code for the wires - I've seen too many cases where someone "saved" by using a larger spool of a single colour for numerous things, and or for both (!) polarities. Red tape (or better, shrink-wrap) on a black wire sort of indicates positive, but only at the ends, and not as well as using red the entire run. Can avoid expensive mistakes later.

Excellent advice! I agree completely.

[BruceS]

I had a similar issue & installed remote controlled 12v lights.
This link is on Ebay in Australia but I'm sure it'd be elsewhere.
Visitors love the ability to run a disco on the back deck!!
https://www.ebay.com.au/itm/4x-12V-D....c101195.m1851