High Amp weatherproof connection for Truck bed

[shade]

You could convince yourself that the wire itself never heats enough to be an issue with 60°C insulation but that's a fairly low temperature just for the environment of a vehicle.

True. I have most of it that's in the engine bay inside conduit, but that's not really a solution. It was cheap and overkill as far as the amperage was concerned, but the insulation clearly wasn't designed for that environment.

I've been planning for a second battery and solar, so pulling a few runs of better wire isn't a big deal.

 

[shade]

105°C minimum

new silicon sheathing can go way higher

I've used some of that when rewiring some CNC mills. Nice stuff.

 

[DaveInDenver]

I've used 90°C XLPE a few times but definitely 105°C or higher is better. It's important to realize that ampacity of wire is how warm it can get before melting through the insulation, not the fusing temperature of the copper, which melts at 1,084°C. The actual threshold isn't the temperature rise of the copper but how high it goes above ambient.

It's obvious the engine and drivetrain are hot under the chassis but don't assume being inside the cabin or living quarters is magic. Parked in the sun, run next to the transmission tunnel, etc. can be a very warm ambient, perhaps 40°C or 50°C, which when you even add a modest resistive heating could be bad.

The reason ABYC can go lower than NEC is moving cool air help while running inside your wall is poor circulation and wrapped with great insulation. On a vehicle it's somewhere in between and varies a lot. And running in conduit makes it worse, not better usually.

 

[shade]

I've used 90°C XLPE a few times but definitely 105°C or higher is better. It's important to realize that ampacity of wire is how warm it can get before melting through the insulation, not the fusing temperature of the copper, which melts at 1,084°C. The actual threshold isn't the temperature rise of the copper but how high it goes above ambient.

It's obvious the engine and drivetrain are hot under the chassis but don't assume being inside the cabin or living quarters is magic. Parked in the sun, run next to the transmission tunnel, etc. can be a very warm ambient, perhaps 40°C or 50°C, which when you even add a modest resistive heating could be bad.

The reason ABYC can go lower than NEC is moving cool air help while running inside your wall is poor circulation and wrapped with great insulation. On a vehicle it's somewhere in between and varies a lot. And running in conduit makes it worse, not better usually.

I used the conduit because I was concerned about the questionable insulation. If it was going to fail, I figured it would be better to have it shielded in the conduit than grounding out on the frame. Hey, it's fused at 10A less than a foot from the power source, so it's not all bad.

 

[john61ct]

running in conduit makes it worse, not better usually.

Yes as BSS Circuit Wizard makes explicit

 

[shade]

Yes as BSS Circuit Wizard makes explicit

Yes, wire heats up from resistance, and conduit traps heat. It also "provides additional physical protection", which was why I used it in the first place.

I doubt my fridge is pulling enough current to make 6' of 10AWG heat up significantly inside some plastic conduit, but I'm going to replace it regardless.

 

[john61ct]

an efficient 12V compressor fridge might pull 4-6A

Should have an ammeter that will actually measure it

 

[shade]

My Fluke 23 multimeter reads amps, but I don't have a clamp meter attachment, so I'd have to borrow one.

I'm not worried about my fridge intermittently pulling as much as 4-6A over 6' of 10/2AWG wire in a few feet of open ended, 1/2" non-metallic liquidtight conduit creating enough heat to cause a problem. In this application, any heat issues are likely to be environmental, not electrically generated.

I am concerned that the wire insulation is only rated to 60°C, which is why I'm going to replace it before any more harm comes to this horse.

Thanks for the help.

 

[Bayou Boy]

With the availability of these there is zero reason not to fuse at the battery terminal.

Terminal Fuses


Also if cost is why you are using landscaping wire go here. Very high quality wire and connectors at reasonable prices. I've seen this same brand wiring on some of the most high end offshore fishing boats made and I've used it for years on both my boats and vehicles.

http://www.genuinedealz.com

 

[shade]

With the availability of these there is zero reason not to fuse at the battery terminal.

Terminal Fuses


Also if cost is why you are using landscaping wire go here. Very high quality wire and connectors at reasonable prices. I've seen this same brand wiring on some of the most high end offshore fishing boats made and I've used it for years on both my boats and vehicles.

http://www.genuinedealz.com

Thanks for the wire link. I was shopping for wire on the remnant wall at the local big box store and found a partial spool of the landscape wire heavily discounted. Obviously, I hadn't given enough thought to the temp rating of the insulation.

I have a Blue Sea Systems 12-circuit fuse block about a foot from the battery, and a 100A BSS circuit breaker between the fuse block and battery. Maybe I'm wrong, but I don't think I'd gain much by adding the complexity of a terminal fuse.

I may replace the fuse block and use something with better, like an IP66 rated Bussmann product. I don't run my truck like a U-Boat Commander, but I can see the advantage of having a sealed fuse box, and it'd be easier to change it out now.

 

[DaveInDenver]

There's nothing wrong with the Blue Sea fuse block. All things being equal having things sealed is preferred but not critical for most of us.

If you have a master breaker you don't gain anything with a battery-mounted fuse.

Just my $0.02 but not enough benefits to bother replacing perfectly good parts. Just replace the wire when you can.

 

[Bayou Boy]

Yes. I wouldn't replace parts if you have a good fusing setup already. I was just posting that so people know there is a really easy compact option. I have an aux battery mounted on my frame rail and used those terminal fuses to fuse the connection with the starting bank and the line leading into my camper top. Easy to mount and significantly less connections in the wiring than any other method.

 

[shade]

Thanks again for the advice. I'll probably start my own thread once I have time to organize my thoughts & parts. I hope @Amp34 doesn't mind the diversion. It's neatly mounted to a Pelfreybilked bracket with the breakers, so maybe I'll keep the BSS fuse block.

There's nothing wrong with a fuse, but I went with a mains breaker because I thought it could also serve as a disconnect in the event I needed to kill the entire fuse block for repairs, or quickly terminate power in an emergency. That came in handy once when I realized that I hadn't used threadlocker on one of the fuse block lugs, and it revealed itself in the middle of a long trip.

 

[shade]

Looks like this would work for any loads I'll see in my truck outside of the winch or battery connections, and the temperature rating will keep it happy anywhere except an obvious hot spot. I doubt I'll beat a $1/foot by much, and then I'd run the chance of getting a questionable product.

http://www.genuinedealz.com/10-awg-gauge-2-conductor-marine-wire-duplex-flat

 

[shade]

I started a similar thread: Low amp, wet location connection for truck bed

Please jump over there if you have a recommendation.