Wire too small for lug ?

Status
Not open for further replies.
D

Davebones

Senior Member
Location
North Of Tampa Fl
Have a Siemens JXD63B350 breaker . ( 350 amps ) I found one of the phases showing signs of heat and the insulation is slightly burnt back . The lug is a 2 hole as this is parallel feeds for each phase . One of the set screws is not tightening down so I wanted to replace the lug . I found only lugs that are rated for cable size 3/0 to 500 mcm . I know they make pin connectors to reduce the size of the cable but what about when the cable is too small for the lug ? The cable's to the breaker are parallel 2/0 per phase . ???
 
Davebones said:
Have a Siemens JXD63B350 breaker . ( 350 amps ) I found one of the phases showing signs of heat and the insulation is slightly burnt back . The lug is a 2 hole as this is parallel feeds for each phase . One of the set screws is not tightening down so I wanted to replace the lug . I found only lugs that are rated for cable size 3/0 to 500 mcm . I know they make pin connectors to reduce the size of the cable but what about when the cable is too small for the lug ? The cable's to the breaker are parallel 2/0 per phase . ???
Click to expand...
No, it's all about compression and if the conductor is too small, it just squeezes out of the way. No add-on adaptors that I'm aware of that would allow that legally. I may be wrong though.

You could mount a splitter block nearby and run one 500MCM/phase from the breaker to the splitter, then land your 2x2/0 /phase on the splitter block, if you have room.

You can, I believe, get reducing crimp splices where you can get little stubs of 3/0 and splice them onto the ends of the 2/0. But they would have to be long enough to allow for the barrel thickness of the splices so they don't interfere with getting the 3/0s into the lugs.

You could also remove the mechanical lugs, install the bolt adaptor for that breaker, and use crimp on ring lugs for the cables. That's how I would deal with it.
 
Status
Not open for further replies.
Top