Help with a CH panelboard

[ptonsparky]

Medium sized.

My help came across this today while replacing a branch circuit CB. Wire on to right lug is burnt back towards where it enters the enclosure. Obviously that lug has been replaced once or never was the correct one. My local CH distributor questioned why the buss extensions were on there. He has the lugs that would typically utilize the two screws holding the extensions on.

Anyone familiar enough with this brand to answer that question?

Any idea what those screws should be torqued to? My help failed to ask that question when they picked up the lugs and new wire.

Hopefully the buss itself hasn’t sustained damage. We will know in the morning

 

[mbrooke]

Judging by the color of those screws relative to the rest... the bus is damaged. the amount if heat the a high resistance connection produces is in orders of magnitude greater than arcing.

 

[synchro]

My local CH distributor questioned why the buss extensions were on there. He has the lugs that would typically utilize the two screws holding the extensions on.

Obviously lugs having 2 screws would keep them from rotating and potentially touching each other. A single screw would allow rotation, as is evident in the picture.
Hopefully they didn't add the extensions because the conductors came up too short after being trimmed because of previous overheating.

 

[ptonsparky]

Judging by the color of those screws relative to the rest... the bus is damaged. the amount if heat the a high resistance connection produces is in orders of magnitude greater than arcing.

The finger under doesn’t look so good either.

 

[ptonsparky]

Obviously lugs having 2 screws would keep them from rotating and potentially touching each other. A single screw would allow rotation, as is evident in the picture.
Hopefully they didn't add the extensions because the conductors came up too short after being trimmed because of previous overheating.

The two left lugs have the stop built onto the back. The right is odd man out.

 

[tom baker]

There is an annex in the NEC that lists torque values.

 

[hillbilly1]

May have been main breaker, but converted to main lug?

 

[infinity]

For some reason that's the way Eaton builds them. Since it has a single mounting hole the stop on the back of the lug keeps it from turning when you torque it down. This is a similar panel that we recently installed.

 

[ptonsparky]

For some reason that's the way Eaton builds them. Since it has a single mounting hole the stop on the back of the lug keeps it from turning when you torque it down. This is a similar panel that we recently installed.
View attachment 2552592

Nice. Thanks.

 

[ptonsparky]

There is an annex in the NEC that lists torque values.

Yes, we use them if we need too. I haven’t looked at these yet but but putting screws into a buss bar makes me nervous. Let alone one that may have the temper gone

 

[ptonsparky]

30 inch pounds for the #10 screws into the buss. We have the immediate concern fixed but the lower connection of the right buss is bad. New guts con the way soon

 

[ptonsparky]

We checked today to see how it was standing up. Parts are two weeks off. The hot spot I found last week was the screw below that is now shielded by parts. Current was within a couple amps. Al buss. New will be Cu.

 

[Dennis Alwon]

I wonder if they cut the wire too short and had to add those extensions???

 

[ptonsparky]

I wonder if they cut the wire too short and had to add those extensions???

Infinity posted a picture (#8) of new instal that has the fingers and lugs with the markings that apparently come that way from the factory. Something was changed at install. The wires were plenty long enough to have reached.

 

[infinity]

Yes that's just the way they build them. Here's a 400 amp version with double lugs per phase. Notice the missing screw directly from the factory.

 

[synchro]

Rob (Infinity),

Nice leaving sharpie marks to indicate if lug terminals have loosened.
I'm impressed with how many pictures of installations you must have. And they must be well organized since you seem to easily pull them up on demand in response to various posts.

 

[infinity]

Rob (Infinity),

Nice leaving sharpie marks to indicate if lug terminals have loosened.
I'm impressed with how many pictures of installations you must have. And they must be well organized since you seem to easily pull them up on demand in response to various posts.

Thanks. Torquing and marking the lug is something that is SOP for many of the guys I work with. For me I do it because I'll know if it burns up (has happened to a co-worker) that it wasn't one of mine.

Regarding the photo's, I wish that they were organized but they're really not. I tend to stay on a project for several years so I can mentally remember the job and then find the photo's based on when I worked there. Someday I will get down to organizing them.

Yes I do take a lot of photo's, the previous one and this one were for our Eaton rep to show them how good their quality control is. Missing bus screw and one of the two not even in all of the way.