Acceptable temperature of wires/lugs during normal operation

[Dadoftheturkeykids]

I know it's normal for wires to get warm under load but how hot is too hot? I've seen Temps in my setup reach 125°f at the inverter junction.

 

[PotusGobbleBottom]

What was your ambient temp when that was read? What amp draw? How long is the wire in question?
There is nothing to be said without knowing your wire gauge and draw.

But I suppose your question isnt "is this a problem" Its How hot is too hot.

My answer is anything over 15F over ambient temp is worthy of investigating if it is not a fuse. How hot is too hot? Well, we try not to melt insulation. And paper burns at 450F Keep it under that

 

[Dadoftheturkeykids]

Ambient temp was 70°f I didn't peek at my shunt to see the actual amp draw but I was pulling 2200 watts to inverter thru 5ft of 4/0 copper welding wire. The wire itself only gets lukewarm but the connection points on the fuse I saw at 125°f... which is pretty far off from 450°f lol

 

[PotusGobbleBottom]

Ambient temp was 70°f I didn't peek at my shunt to see the actual amp draw but I was pulling 2200 watts to inverter thru 5ft of 4/0 copper welding wire. The wire itself only gets lukewarm but the connection points on the fuse I saw at 125°f... which is pretty far off from 450°f lol

Ok sorry to be insensitive but.....Watts means nothing with out voltage. Volts X Amps = Watts. Watts/voltage= Amps

What voltage is your battery?

 

[PotusGobbleBottom]

but the connection points on the fuse I saw at 125°

Yup, Fuses by nature get warm.
I think mine at a 80 amp draw gets to about 130F Mine is an ANL fuse. They are notoriously warm.

If you are SURE that the fuse lug connections are good, and there are NO washers between the lug and the fuse, You are fine.
No drilling lugs either, NO bright ideas lol

 

[OffGridInTheCity]

I have 4 x 4awg wires between 2 x Midnite Classics and the main battery bus in 2" flex conduit of about 15ft. The wires carry up to 80a and can reach 55-60C / 131-140F as they come out of the conduit at 65-80a range. I use the Midnite battery temp probes to monitor/record this info. This is warm to the touch but not what I'd call hot.

Midnite Classic 150s can output up to 86a but I have it throttled down to 80a due the breakers.

It's been 6 years of this and it seems OK for the wires to reach 55C for maybe 10 weeks per year.

 

[Dadoftheturkeykids]

Generally I have about 13v on my battery bank. But yeah 12.8 nominal. Good to know how hot is too hot, but I guess 130ish is normal around the fusing? I am guessing that I'm pulling around 215amps on the norm

 

[PotusGobbleBottom]

I am guessing that I'm pulling around 215amps on the norm

If this is the case, you are perfectly fine. In fact, doing good I would say.

 

[Dadoftheturkeykids]

Thanks for the feedback

 

[PotusGobbleBottom]

but I guess 130ish is normal around the fusing

That is my experience.