DC Electrical Question

[DLCameron2]

Hello:

I am installing WESMAR stabilizers on our boat, the power supply is 12V 8amp requirement on a 10amp breaker. My question is I want to run the power supply wire from my 12V supply on the bridge, the length of the wire will be approximately 35 ft, will 12AWG be heavy enough for this length?

Thanks.

DC

 

[Amp Tramp]

To be safe a #10 awg would be better

 

[MikeP]

I have a spreadsheet based on ABYC/Nigel Calder recommendations. When I plug in your values I get this:

System Voltage 12 Volts Allowable V-Drop 3% Percent Total Length of Circuit 35 feet Avg Current 8 Amperes Conductor in Engine Space Y (Y/N) Temp Rating of Insulation 105 deg C


Allowable V-Drop 0.36 Volts AWG to be used 10 AWG Wire Ampacity 51 Amps Absolute Max. Fuse Rating 76.5 Amps
I assume that the 35 feet represents total wire run both ways. That is, the actual distance from the device to the breaker measured the way wire would be run is around 17 feet. If 35 ft is the actual distance, then for wiring purposes, it is 70 ft and AWG 7 is specified. I've never seen 7 so AWG 6 would be needed.

Also, if you match the breaker size - 10A - rather than the device's average draw, you would use AWG 9 (8, in reality) for the 35 ft run.

 

[MikeP]

Oops, I see that the spreadsheet format did not carry over to the post - it looked OK as I was replying. Oh well...