Breaker issue

[lil_wyatt7]

I run a small shop in Michigan and the 2010 GE panel had a breaker that overheated and melted part of the bus. The bonding strap was still installed even though the main disconnect is outside. Could improper bonding cause this or is it more likely water got in through the conduit?

 

[d@rkSm0k3]

Possibly... Did you try physically checking if there's any source of water that could seep into it?

 

[lil_wyatt7]

Possibly... Did you try physically checking if there's any source of water that could seep into it?

Thanks! I'm going to do a thorough check for any water intrusion paths this week and get everything sealed up properly.

That said, in your experience, what's the more common culprit for a melted bus bar like this? Is it typically corrosion caused by moisture or is it more often just a poor/loose connection where the breaker stabs onto the bus? I'm trying to figure out if I'm hunting for a leak or just evidence of a bad connection.

 

[PGB1]

I don't know if this is applicable to your load center, Lil_waytt7, but I've replaced dozens and dozens of GE's THQL series circuit breakers whose clip worked loose over time due to mild heat-cool cycles. The resultant mini-arcing melted the bus lug.

It's not a fire hazard, but a nuisance when one runs out of breaker spaces on the bus. You can still buy bus bars for that load center if you need that melted space. Try Electrical Advertiser's web site for many suppliers.

Their THQB don't suffer from the same problem unless the bus screw works loose.

Certainly what you mentioned about the N/G bonding strap is correct. The neutral bar should be isolated from ground since there will be a separate natural and ground coming in from the disconnecting means ahead of the load center. Unfortunately, you might end up having to move all the equipment grounding conductors off of the neutral bar.

Hope This Helps,
Paul

 

[lil_wyatt7]

I don't know if this is applicable to your load center, Lil_waytt7, but I've replaced dozens and dozens of GE's THQL series circuit breakers whose clip worked loose over time due to mild heat-cool cycles. The resultant mini-arcing melted the bus lug.

It's not a fire hazard, but a nuisance when one runs out of breaker spaces on the bus. You can still buy bus bars for that load center if you need that melted space. Try Electrical Advertiser's web site for many suppliers.

Their THQB don't suffer from the same problem unless the bus screw works loose.

Certainly what you mentioned about the N/G bonding strap is correct. The neutral bar should be isolated from ground since there will be a separate natural and ground coming in from the disconnecting means ahead of the load center. Unfortunately, you might end up having to move all the equipment grounding conductors off of the neutral bar.

Hope This Helps,
Paul

Both of you pointed me away from bonding and toward outside factors like moisture or heat cycles, so that helps narrow it down. Since the bus is already showing damage, I’ll need to plan a fix soon. In your experience, is it more practical to replace the bus bar on a GE panel like this or is a full panel change usually the better route?

 

[PGB1]

Both of you pointed me away from bonding and toward outside factors like moisture or heat cycles, so that helps narrow it down. Since the bus is already showing damage, I’ll need to plan a fix soon. In your experience, is it more practical to replace the bus bar on a GE panel like this or is a full panel change usually the better route?

Knowing GE, I pretty much doubt that water caused this damage. Their live parts are well stood off and water would drip behind. Is the bottom of the tub rusty? As an example: The Pontiac Silverdome had hundreds of GE load centers, switches and panel boards. That was a cold, damp, leaky place. None of the GE equipment ever shorted due to water during the years that I worked there. (They also had a couple hundred FPE Stab-Lok. Those melted or burned as if on a schedule!)

Does your load center use THQL series GE breakers? If so, the fault isn't the bus bar. (See #4). There's no need to replace the bus or load center.
Do you have room to skip the melted spot on the bus? Perhaps a tandem ("Piggyback") breaker will free up a spot so you can forever ignore the burned lug. Snap in a closure over the now empty spot on the dead-front cover.

If You Replace The Bus:
Replacing the bus is a lot quicker than replacing the entire load center. The new tub will certainly be larger due to the newer gutter space requirements. If your shop is piped, the project then becomes rather lengthy.

Bus Replacement:
For a replacement bus, I suggest starting with Salinger. https://salingerelectric.com/ or 248 585-8330.

They have lots of new and used equipment and are a family owned business with lots of nice (and knowledgeable) people. If in Michigan you happen to be in the Metro Detroit area, the main location is on the north side of 15 Mile east of 75 in Troy. (They also ship items.) If you go there, ask for a tour. It's a fun place to explore!

They also have a store in Romeo off 33, between Van Dyke Freeway and Romeo Plank and one in Farmington Hills somewhere. I've not been to those two, but the one in Troy is loaded with treasures.

Plan B:
At the web site https://electricaladvertiser.com/ click on the On Line Publications tab at the top. This will bring up copies of the mailed magazine. Inside you will find lots and lots of used equipment sellers. One surely will have the bus that you seek.

Hope This Is Helpful!
Paul

 

[lil_wyatt7]

Knowing GE, I pretty much doubt that water caused this damage. Their live parts are well stood off and water would drip behind. Is the bottom of the tub rusty? As an example: The Pontiac Silverdome had hundreds of GE load centers, switches and panel boards. That was a cold, damp, leaky place. None of the GE equipment ever shorted due to water during the years that I worked there. (They also had a couple hundred FPE Stab-Lok. Those melted or burned as if on a schedule!)

Does your load center use THQL series GE breakers? If so, the fault isn't the bus bar. (See #4). There's no need to replace the bus or load center.
Do you have room to skip the melted spot on the bus? Perhaps a tandem ("Piggyback") breaker will free up a spot so you can forever ignore the burned lug. Snap in a closure over the now empty spot on the dead-front cover.

If You Replace The Bus:
Replacing the bus is a lot quicker than replacing the entire load center. The new tub will certainly be larger due to the newer gutter space requirements. If your shop is piped, the project then becomes rather lengthy.

Bus Replacement:
For a replacement bus, I suggest starting with Salinger. https://salingerelectric.com/ or 248 585-8330.

They have lots of new and used equipment and are a family owned business with lots of nice (and knowledgeable) people. If in Michigan you happen to be in the Metro Detroit area, the main location is on the north side of 15 Mile east of 75 in Troy. (They also ship items.) If you go there, ask for a tour. It's a fun place to explore!

They also have a store in Romeo off 33, between Van Dyke Freeway and Romeo Plank and one in Farmington Hills somewhere. I've not been to those two, but the one in Troy is loaded with treasures.

Plan B:
At the web site https://electricaladvertiser.com/ click on the On Line Publications tab at the top. This will bring up copies of the mailed magazine. Inside you will find lots and lots of used equipment sellers. One surely will have the bus that you seek.

Hope This Is Helpful!
Paul

Paul, your focus on the GE THQL breakers gives me a specific item to check at the shop. I'll also look into the local suppliers you mentioned in Michigan. Regarding your tandem breaker suggestion, is using one to bypass a damaged lug considered a permanent and safe repair?

 

[PGB1]

. Regarding your tandem breaker suggestion, is using one to bypass a damaged lug considered a permanent and safe repair?

Hi Lil_Wyatt,

As long as the load center or panel board is rated to allow tandems (piggyback) it is very safe and common (sanctioned) practice.
Not a very helpful answer, huh?

If you post a photo of the label, showing the drawing of the bus (if present) and showing model number, I probably will be able to help more.

Easiest Label To Read:
Attached below is a drawing I swiped off the inner-tube-web-net. The photographer shows where tandems can go on that particular panel. If your label looks like that, you're are good-to-go with piggyback circuit breakers in certain spots.
Not having such a drawing does not indicate Yes or No. A photo of your label, showing model number will help a lot.

A Clue:
Does the label say "CTL" on it & have 42 spaces? If so, you may not be able to add a tandem. (Some genius at the hardware store will show you how to file off the rejection tab on the tandem so it will work in any panel. Don't do it.)

When you get a chance, send a photo of the label and a breaker space count. (Or check the model number on line for the Technical Data Sheet for that center.)

Paul

 

[lil_wyatt7]

Hi Lil_Wyatt,

As long as the load center or panel board is rated to allow tandems (piggyback) it is very safe and common (sanctioned) practice.
Not a very helpful answer, huh?

If you post a photo of the label, showing the drawing of the bus (if present) and showing model number, I probably will be able to help more.

Easiest Label To Read:
Attached below is a drawing I swiped off the inner-tube-web-net. The photographer shows where tandems can go on that particular panel. If your label looks like that, you're are good-to-go with piggyback circuit breakers in certain spots.
Not having such a drawing does not indicate Yes or No. A photo of your label, showing model number will help a lot.

A Clue:
Does the label say "CTL" on it & have 42 spaces? If so, you may not be able to add a tandem. (Some genius at the hardware store will show you how to file off the rejection tab on the tandem so it will work in any panel. Don't do it.)

When you get a chance, send a photo of the label and a breaker space count. (Or check the model number on line for the Technical Data Sheet for that center.)

Paul

Okay, I’ll get a photo of the panel label tomorrow to check for the tandem rating. If the label’s missing or illegible, is looking up the model number my only other option?

 

[PGB1]

Okay, I’ll get a photo of the panel label tomorrow to check for the tandem rating. If the label’s missing or illegible, is looking up the model number my only other option?

Looking up the model number will be impossible if the label is missing or illegible.
Can you find a label on one of the circuit breakers? That will tell us if piggy back or half-space breakers are available.

 

[lil_wyatt7]

Looking up the model number will be impossible if the label is missing or illegible.
Can you find a label on one of the circuit breakers? That will tell us if piggy back or half-space breakers are available.

In the next day or two, I'll go to the shop, take a clear photo of the main panel label and pull a breaker to check for any tandem markings.

Will post what I find right after. Appreciate the detailed help!