Page 1 of 1

DC Breakers with too small a contact area on terminals?

PostPosted: Mon Jan 07, 2019 9:55 pm
by Jman
I brought some single pole ETA breakers that are 60 & 80A, (Mfr. Part No8345-B01A-U3M0-DB1B1B-80A) used as inline switches for 50-60amps continuously at 12V. Both models terminals have M6 bolt threads, but the contact area at the bottom of the thread is just 7mm in diameter & even a 6mm stud ring lug just doesn't look to get a decent contact. A google search shows images of the switch & you can see how small the contact area is.

Does this look safe for these currents?

thanks

Re: DC Breakers with too small a contact area on terminals?

PostPosted: Fri Jan 11, 2019 8:20 pm
by qed
you should clamp the lug between two nuts & washers
use tin plated coper washers and make shore everything is clean

Re: DC Breakers with too small a contact area on terminals?

PostPosted: Mon Jan 14, 2019 12:26 am
by Jman
qed wrote:you should clamp the lug between two nuts & washers
use tin plated coper washers and make shore everything is clean

I don't know if that's good? The nuts look metal or brass & perhaps not good at high currents transferring through to the threads?
I just bolted it so the lug is in direct contact with the bottom flat metal area. Used the smallest lug I could. An hour test at high current and the switch & contacts get some what warm, but from what I keep reading thats fine for all switches.