What gauge wire do I need for fridge circuit?

Everyone should invest in a hydraulic crimpers. You can't buy good wire cheaply, but you can get 25' x 8 gauge jumper cables for $10. Use the crimper to make new lugs and run them to a distribution junction.

 

Larger cable = less resistance = less voltage drop = more capacity.

6 AWG cable is overkill, and the earlier chart posted isn't granular enough for lower amperage connections. This is a far better chart for low amperage applications...



You'd could use 14 AWG if you're only doing the fridge but you'd be pushing it; 10 AWG would probably be better. At the end of the day bigger is better to a point for safety, but there's no reason to waste money on huge cables for a low draw application.


With that said, you could EASILY tap into the power on the trailer hitch for that low of amperage without having to do any wiring whatsoever. https://www.etrailer.com/faq-wiring.aspx has info on what wire to tap for that off of the trailer hitch. That's the fastest, easiest, and cheapest option -- plus it's already fused. You'd just splice in on the battery output and be done.

 

I think it's 13A not 1.3A. A house fridge has ten times the voltage so amp draw for that isn't an apt comparison. I'd be fine with multiple power outlets on a single fused circuit as long as the total draw didn't exceed the wire max but even in homes relatively high draw appliances are separately fused. That's part of the UBC and should be applied as common sense to our truck mods.

 

Agree in no way its 1.3 amp draw and I offer 6 AWG is whats needed though 8 awg may be fine depending on run. 14 gauge is for much smaller draw. I did an interior inverter install and due to length of run it required 6 awg and a 150 amp breaker near the battery.

 

IIRC, resistance is roughly inversely proportional to diameter (it’s a surface area thing since current tends to run in the surface rather than through the whole wire). That’s in solid wire. Braided gets more complicated.

 

There is no way a mobile fridge draws 13A current continuous. The current may peak a bit higher when the compressor starts, but operational amperage will be far less. My CC40 is rated to draw 1.10 Ah/h usage against a power bank, which converts to 13.2w... At 12v, that's 1.1A.

I adjusted my post assuming 13A in case I'm still wrong (which happens), but I still think 6AWG is way overkill.

 

I do agree that the fridge should not draw that many amps or close to it. I beleive the issue is usually startup and most use a factor of 5 in figuring possible draw. So for the that start up you have quite a bit of juice on the line compared to normal operation. I in no way claim to be an electrical engineer but have fair amount of experience working with inverters (have one in my Tacoma that I use often) and other electronics installation experience.

 

13A at 12V is only 156 watts so it seems reasonable to me. 13A to a house fridge at 110 AC is 1430 watts. Unless it's poorly insulated it shouldn't run all the time but when it does it will draw close to that amount which is still only a small fraction of what an moderate air compressor draws @ 30-40A. I agree that #6 is overkill for just the fridge alone but not for an auxiliary fuse block while at the same time #14 is not nearly enough for any distance at that current and even #12 would be pushing it with only 10 ft of wire.

 

I hope OP included the amps for his blender in the calculations before running those wires, because right now he’s probably camping on the beach in some warm blue tropical water cove in Baja California fixing to make another round of Margaritas with it and is either noticing that his blender and fridge don’t work well together and there’s a bad smell comming from his truck, or they’re both purring away and he’s passed out after his fourth round I hope he’s getting sunburnt.

Ok, I’m just jealous because I didn’t get to go to Baja and drove to Texas instead, the lucky bum!