Corroded terminals

[tom baker]

Neutral and EGC terminals on a older Sq D homeline are corroded, thankfully copper wire. The worst is the EGC, I tried a bit to loosen it, I think I need a big screwdriver 3/8" bit and sliding T Bar. Is there any solvent I could use to try and loosen these up? Other suggestions?

 

[ATSman]

Tom
I would start with what I use on my truck battery terminals: baking soda and white vinegar with an old tooth brush.
Then follow with Scotch Brite pad and a good spray lubricant like CRC 2-26.

 

[tom baker]

Good tip on cleaning but I need to loosen the slotted screw, CRC2-26 for that

 

[synchro]

If you still have difficulty loosening the screws, a suggestion is to try tightening them first just to break them loose.
I suspect that the threads on the set screws are more corroded on the their back ends, and so unscrewing that corroded part outward through the lug might be more difficult than screwing it inward. If you can break it loose then you can go from there.