Wire Size and Heat !

[SolarVet]

Anybody have any good Ideas on a way for adapting to larger cable...4gauge wire dont cut it when 75 amps..Wire gets really warm.

[boB]

A ferrule is one way to connect two different sizes of wire.

http://www.ferrulesdirect.com/

Or go to the local hardware store and get some crimp wire to wire connectors of the proper size
to joint two difference sizes of wire together.

What is the ambient temperature where the wire is ?  High ambient will of course
add to how hot the wire is.

Where is the wire getting hot ?  Is it hot near one of the connection points or terminal blocks ?
If so, the problem may just be a connection that is not tight enough.  4 gauge should be
big enough for up to 100 amps or so.

boB

[SolarVet]

My setup has dual 4 gauge pairs going to terminal blocks.  I have 4 Gauge wire coming from Positive fused at 100 amps and the Ground to a separate terminal block.
At most there is 1 foot of wire from the charge controller with fuse in between of course. Feeding the 2 terminal blocks to the battery's.
This 1 foot section of wire is gets very warm. All connections has been checked and gone over. Even the fuse block gets hot as hell and can burn your fingers.

[SolarMusher]

My setup has dual 4 gauge pairs going to terminal blocks.  I have 4 Gauge wire coming from Positive fused at 100 amps and the Ground to a separate terminal block.
At most there is 1 foot of wire from the charge controller with fuse in between of course. Feeding the 2 terminal blocks to the battery's.
This 1 foot section of wire is gets very warm. All connections has been checked and gone over. Even the fuse block gets hot as hell and can burn your fingers.

Could you send a picture where we can see all the wiring?
Erik

[Halfcrazy]

Yes 75 amps in a #4 should NEVER get hot enough to burn you. If you have something getting that hot I would turn the system off and figure it out. Might be looking for a high resistance connection some Where.

Ryan

[dgd]

My setup has dual 4 gauge pairs going to terminal blocks.  I have 4 Gauge wire coming from Positive fused at 100 amps and the Ground to a separate terminal block.
At most there is 1 foot of wire from the charge controller with fuse in between of course. Feeding the 2 terminal blocks to the battery's.
This 1 foot section of wire is gets very warm. All connections has been checked and gone over. Even the fuse block gets hot as hell and can burn your fingers.

There is something seriously wrong here. #4 has no problem with 75 amps. But the clue here is that the fuse block  is hot  and the  #4 may  be just conducting the heat away from the hot fuse block. If it gets hot enough to burn you, then there is a real fire risk. I'm surprised the fuse has not melted already.
I would suggest removing the fuse and holder from the circuit and in it place put a midnite/outback breaker with bolt down copper ring lugs on the #4 to the breaker.

dgd

[SolarVet]

I switched out the ANL fuse and holder today, To a Bussman 150 amp Breaker switch. I will monitor the wire and the Breaker.
I believe dgd maybe correct on this Heating issue. And so I went and purchased a Dc Breaker to see if this solves the issue.
I noticed the fuse holder heat was bad. And that the ground wire was just barely warm to touch. But the Positive wire was very warm.
So Ill update soon once the power is High amps again,,Tomorrow I figure.

[Photowhit]

Well I saw this post and it appears settled and understood...

...but I'm going to have an array that is a pretty good distance from my charge controller, (array 3...lol) and since I hope to use some #2 wire that I have on hand wired into some smaller breakers in my E-panel, I had saved a link for someone's post for "tab connectors" which have a slightly smaller surface for connections into compression type fittings.

http://www.bdbatteries.com/lugs.php

I doubt they are UL listed, any opinions on their suitability for use in a Midnite 63amp breaker and into a grounding bar would be of interest. #2 will fit into the 63 amp breaker though spec'd as a max of 4 gauge and I would just do with out there.