# Switchboard Explosion



## NEVERLATE (Jul 25, 2010)

This is one of my latest "interesting" jobs that will give everyone an idea of what we do. 

A local plant that produces salad dressings and other condiments suffered a catastrophic failure last week of a GE HPC 3000A switch serving one of there two switchboards. The blast was contained in the cabinet the switch was mounted in but destroyed the switch and all the conductors. After an electrical contractor came in and connected the plant to 4 trailer mounted generators, we get to do the fun work. 

We removed all the bus pieces within the cabinet and cleaned them all back at our shop. We acquired a surplus switch that exactly matched the original. Once everything was ready, the customer gave us a 30hr shutdown period to rebuild the switchgear. We went in and completely cleaned the cabinet and reassembled all the buss pieces and installed the new switch. We had a GE EE come in and certified that the switchboard was as good as new and restored power to the plant. 

Upon restoring power, we have determined that the switchboard that failed is commonly loaded to 85% and is believed to be overloaded regularly. This coupled with the additional stress caused by harmonics is overworking the SWBD.


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## Zog (Apr 15, 2009)

So that's wherre that switch went 

Those are always fun jobs, used to do it myself, now I am on the other end of things, building breakers and switchgear to match obsoleted gear when something like that happens, get 20 calls a day like that.


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## NEVERLATE (Jul 25, 2010)

Zog said:


> So that's wherre that switch went
> 
> Those are always fun jobs, used to do it myself, now I am on the other end of things, building breakers and switchgear to match obsoleted gear when something like that happens, get 20 calls a day like that.


 
That was our second such event in 2 weeks. We had another plant that makes a popular brand cereal that had a pringle switch that had been opened and when they closed it back, the C phase knife didnt go into the contacts, it was resting on top of them. It too exploded quite violently.


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## Shorty Circuit (Jun 26, 2010)

NEVERLATE said:


> This is one of my latest "interesting" jobs that will give everyone an idea of what we do.
> 
> A local plant that produces salad dressings and other condiments suffered a catastrophic failure last week of a GE HPC 3000A switch serving one of there two switchboards. The blast was contained in the cabinet the switch was mounted in but destroyed the switch and all the conductors. After an electrical contractor came in and connected the plant to 4 trailer mounted generators, we get to do the fun work.
> 
> ...


I expect to hear more and more of this kind of story as American industry, the government, and utilities have refused to perform routine maintenance, replace capital equipment that is obsolete, worn out, review and manage their capital plant. What if it had taken more than 30 hours to rebuild? I guess we'd all have to mix our oil, vinegar, salt, pepper, garlic powder, onion powder, and other secret spices and herbs ourselves. Oh it would have been the end of the world I tell ya.

:wallbash::drink::stuart::w00t:


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## NEVERLATE (Jul 25, 2010)

Shorty Circuit said:


> I expect to hear more and more of this kind of story as American industry, the government, and utilities have refused to perform routine maintenance, replace capital equipment that is obsolete, worn out, review and manage their capital plant. What if it had taken more than 30 hours to rebuild? I guess we'd all have to mix our oil, vinegar, salt, pepper, garlic powder, onion powder, and other secret spices and herbs ourselves. Oh it would have been the end of the world I tell ya.
> 
> :wallbash::drink::stuart::w00t:


The good news for what we do is, you can pay us $5000 a year now for a comprehensive maintenance program or $55000 later when your board explodes. Either way, we get paid.


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## MDShunk (Jan 7, 2007)

Unwritten rule of ElectricianTalk #14: When you start a thread about a dramatic service call, it is required that you post pictures.

How 'bout it? :thumbsup:


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## NEVERLATE (Jul 25, 2010)

MDShunk said:


> Unwritten rule of ElectricianTalk #14: When you start a thread about a dramatic service call, it is required that you post pictures.
> 
> How 'bout it? :thumbsup:


I know, I know. I'm working on it.


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## brian john (Mar 11, 2007)

All new insulators and insulating boards?

Tested and signed off on? GFP, Ductored and meggered.


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## frenchelectrican (Mar 15, 2007)

Neverlate.,

Was that is a Kraft plant ?? if so I been there once before many years ago. { with one of my other frenid electrician whom show me around the area }

Merci.
Marc


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## NEVERLATE (Jul 25, 2010)

brian john said:


> All new insulators and insulating boards?
> 
> Tested and signed off on? GFP, Ductored and meggered.


 
Yes to all the above. Signed off by GE's EE who considered it to be in original UL listed condition and signed off by the AHJ.

We are a professional electrical testing and switchgear maintenance company with 35 yrs in the buisiness. We have PE's and EE's on staff. We are not an electrical contractor bolting stuff together.


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## NEVERLATE (Jul 25, 2010)

frenchelectrican said:


> Neverlate.,
> 
> Was that is a Kraft plant ?? if so I been there once before many years ago. { with one of my other frenid electrician whom show me around the area }
> 
> ...


No, not a Kraft foods plant.


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## BILLY 101 (Jul 29, 2010)

I would be very interested to know WHY it exploded.
Even if there was dead short on the line side of the board it should not explode.
The usual reason for this is inadequate short circuit protection. 
Meaning the switch or CB must be rated to interrupt the available short circuit current without damage to equipment. 
I surprised the EE and the AHJ didn't ask this question. 

Bill


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