pitted busbar

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Energy-Miser

Energy-Miser

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Location
Maryland
Happy Inaug. day everyone. Now to the question:
There is some pitting where busbar in the panel connects to one of the two poles of the 200 amp main breaker. I am replacing the main breaker as it now trips on currents well below 200 amps (due to the heat damage it has suffered, I believe). But is there a way to build up the pitted area of the busbar, short of replacing? Thank you for your input. Best wishes, E/M.
 
Energy-Miser said:
It is a GE. The main is TQD22200. The connection to the busbar is through flat metal to flat metal with a quarter inch screw between them. E/M
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I could replate and repair it but you can replace this little thing cheaper, however, you should figure out the cause. Can you post a picture?
 
Energy-Miser said:
It is a GE. The main is TQD22200. The connection to the busbar is through flat metal to flat metal with a quarter inch screw between them. E/M
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I would buy a new panel and start fresh. Your already replacing the breaker a new panel may be more cost effective and take less time than to replate the buss.
 
Replace the panel or replace the Guts. The damage is done ,but "What"

caused the damage? That's the first thing I think of, when I encounter

any electrical problem. Whatever damaged the bus, will also, raise it's

ugly head, and damage the new bus.
 
So did the one can get sprayed and the other didn't ?

What is the enviroment? How old are these cans ?

If it void of abuse, I'd notify the the Distrist Rep!
 
Yes - please post picture. Only way I could imagine this happening is through poor connections. I know most electricians have never done this, but if you could get a ductor and check those connections you would never want to be without your own ductor. I always used them on every bucket - reading back to the incoming connection checking for possible problems, and have found bolts that were only finger tight.
 
benaround said:
Just a little bit on the expensive side for other than industrial facilities.
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Try GE Rents.. Atlanta I think. Not nearly as expensive if found after MCC energized and in use. Client would probably never call that EC back if they knew it was easily preventable. Think of the value of something like that when you are talking to a client or possible customer.
 
Karl H said:
Replace the panel or replace the Guts. The damage is done ,but "What"

caused the damage? That's the first thing I think of, when I encounter

any electrical problem. Whatever damaged the bus, will also, raise it's

ugly head, and damage the new bus.
Click to expand...

I think it may have been caused by the screw not having been tightened when the main was first installed. It seemed tight when I tried to unscrew it, but that may have been due to the build up of the burned material, etc. The heat generated at the junction ultimately damaged the main, is my thought. E/M.
 
If the bus attachment point (where that little angle piece meets the main bus) is even slightly pitted or discolored, bad news..the whole bus (section) needs to be replaced.

Any attempt to clean, file or polish that damage will result in a high-resistance connection that WILL fail again..rapidly.

Not to mention voiding the bus and equipment listing.
 
cadpoint said:
So did the one can get sprayed and the other didn't ?

What is the enviroment? How old are these cans ?

If it void of abuse, I'd notify the the Distrist Rep!
Click to expand...

Panel was installed in 1994. Only the right side leg had the damage, the other side was perfectly fine. The current passed through the main that I observed was around 120 amp, well below the 200 amp rating of the breaker.
 
RHJohnson said:
Yes - please post picture. Only way I could imagine this happening is through poor connections. I know most electricians have never done this, but if you could get a ductor and check those connections you would never want to be without your own ductor. I always used them on every bucket - reading back to the incoming connection checking for possible problems, and have found bolts that were only finger tight.
Click to expand...

How much do one of these run ? ($).
 
Energy-Miser said:
How much do one of these run ? ($).
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Well there not cheap 2.5K + - and some good reading of the devices and people that use them...

You noted taking a piece out, an "L" shaped piece. My question is will these threads that hold that piece still be good and what does one do the deal with that if you have to ? Re-tapping or next size ? What's the manufacture have to say about that?

So it comes down to a loose bolt causing pitting ?
I've heard of bolts desolving between bus panels but not pitting, but I didn't know to ask!

So its just the arcing that causing the pitting > Right ?

Anybody got any pitting pictures? TIA
 
Energy-Miser said:
I think it may have been caused by the screw not having been tightened when the main was first installed. It seemed tight when I tried to unscrew it, but that may have been due to the build up of the burned material, etc. The heat generated at the junction ultimately damaged the main, is my thought. E/M.
Click to expand...

I'd replace the buss.
 
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