Cleaning corroded panelboards

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Pizza_Guy

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At my work, we have a few dozen new panelboards that have been exposed to the elements. some of the bus bars have some mild corrosion. I'm looking for a way to restore them. Any suggestions?
I would even consider something like electrolysis or sandblasting. We have the technology.
 
Pizza_Guy said:
At my work, we have a few dozen new panelboards that have been exposed to the elements. some of the bus bars have some mild corrosion. I'm looking for a way to restore them. Any suggestions?
I would even consider something like electrolysis or sandblasting. We have the technology.
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My opinion. Junk them.
You should have taken better care.
Are the long term liabilities worth it?
 
ptonsparky said:
My opinion. Junk them.
You should have taken better care.
Are the long term liabilities worth it?
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Agree. Many AHJ's won't even let you clean a new panel bus that the painters got latex paint on - there supposedly no listed or recognized way of cleaning them.
 
They should be replaced, but given the current supply chain issues, that could take months.
Short term, I’d try to take some thermal readings at maximum load to try to pinpoint hot spots and deal with them as best you can. Maybe repeat the thermal survey regularly until they can be replaced.
 
my personal opinion is external corrosion on bus bars just does not matter. it does not affect current flow at all. what might affect current flow is corrosion between the bus bar and what it is connected to. I think if you disconnect such connection you will likely find the connection itself is pristine.
 
ptonsparky said:
These are 'new' never been installed panels?
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I would not get real excited about it. Unless the corrosion is really bad it probably won't require much beyond use of a pencil eraser to remove whatever corrosion might be at issue. There is a big difference between what might be legalistically acceptable and what is perfectly safe to do.

Now if the PB had been underwater for a week, then I would probably just toss them, but a little incidental corrosion is not likely to hurt anything.
 
petersonra said:
I would not get real excited about it. Unless the corrosion is really bad it probably won't require much beyond use of a pencil eraser to remove whatever corrosion might be at issue. There is a big difference between what might be legalistically acceptable and what is perfectly safe to do.

Now if the PB had been underwater for a week, then I would probably just toss them, but a little incidental corrosion is not likely to hurt anything.
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Yes, never installed.
 
retirede said:
They should be replaced, but given the current supply chain issues, that could take months.
Short term, I’d try to take some thermal readings at maximum load to try to pinpoint hot spots and deal with them as best you can. Maybe repeat the thermal survey regularly until they can be replaced.
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These have not been installed. Most are in good condition. Just looking for ways to ensure a good contact with the breakers during installation.
 
After Hurricane Katrina, I got involved in a lot of this sort of thing while working for a manufacturer. Insurance companies were looking for documented ways to limit their exposure to having to pay for replacing equipment. There were more resources available at the time when I made a list to give out to people, almost all of those documents are now lost to time. But there was one from NEMA that is still available. https://www.nema.org/docs/default-s...elines-handling-water-damaged-elect-equip.pdf

Basically though, that just says that breakers should NOT be reused, panels and gear CAN but the manufacturers need to be involved in the decision. One reason is that water may have compromised the bus insulators and braces, allowing tracking across the contaminated surfaces and leading to flashovers (this document doesn’t go into that much detail, but that’s the reasoning). In my case our equipment was all power electronics (Soft Starters) so there was no reasonable recovery method. We had one customer replace the Soft Starters but keep the breakers and bypass contactors, they had an internal flashover inside of a breaker and the contactors all failed within 3 months of being energized.

Bottom line, I would not recommend reusing it. SCCR and arc flash ratings are always based on equipment being in original factory condition with proper maintenance to be valid. Yours now misses on both counts. So if something DOES go wrong and someone gets hurt, even a crappy lawyer can drive a lawsuit bus through that opening.
 
Jraef said:
After Hurricane Katrina, I got involved in a lot of this sort of thing while working for a manufacturer. Insurance companies were looking for documented ways to limit their exposure to having to pay for replacing equipment. There were more resources available at the time when I made a list to give out to people, almost all of those documents are now lost to time. But there was one from NEMA that is still available. https://www.nema.org/docs/default-s...elines-handling-water-damaged-elect-equip.pdf

Basically though, that just says that breakers should NOT be reused, panels and gear CAN but the manufacturers need to be involved in the decision. One reason is that water may have compromised the bus insulators and braces, allowing tracking across the contaminated surfaces and leading to flashovers (this document doesn’t go into that much detail, but that’s the reasoning). In my case our equipment was all power electronics (Soft Starters) so there was no reasonable recovery method. We had one customer replace the Soft Starters but keep the breakers and bypass contactors, they had an internal flashover inside of a breaker and the contactors all failed within 3 months of being energized.

Bottom line, I would not recommend reusing it. SCCR and arc flash ratings are always based on equipment being in original factory condition with proper maintenance to be valid. Yours now misses on both counts. So if something DOES go wrong and someone gets hurt, even a crappy lawyer can drive a lawsuit bus through that opening.
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But he is not talking about something that has been submerged in water. he is talking about some minor corrosion. Over time the bus bars are going to corrode a little anyway.
 
Jraef said:
He said "exposed to the elements" which I interpreted as having been allowed to get wet and thus corroded.
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hard to know what he meant. but if they were never installed they may have been in the factory packaging which would probably have given pretty good protection even if the packaging got wet.
 
petersonra said:
hard to know what he meant. but if they were never installed they may have been in the factory packaging which would probably have given pretty good protection even if the packaging got wet.
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Yes, but of course that's why all equipment instructions I've ever read tell you to store in a dry location and/or provide space heaters for condensation protection.
 
Jraef said:
After Hurricane Katrina, I got involved in a lot of this sort of thing while working for a manufacturer. Insurance companies were looking for documented ways to limit their exposure to having to pay for replacing equipment. There were more resources available at the time when I made a list to give out to people, almost all of those documents are now lost to time. But there was one from NEMA that is still available. https://www.nema.org/docs/default-s...elines-handling-water-damaged-elect-equip.pdf

Basically though, that just says that breakers should NOT be reused, panels and gear CAN but the manufacturers need to be involved in the decision. One reason is that water may have compromised the bus insulators and braces, allowing tracking across the contaminated surfaces and leading to flashovers (this document doesn’t go into that much detail, but that’s the reasoning). In my case our equipment was all power electronics (Soft Starters) so there was no reasonable recovery method. We had one customer replace the Soft Starters but keep the breakers and bypass contactors, they had an internal flashover inside of a breaker and the contactors all failed within 3 months of being energized.

Bottom line, I would not recommend reusing it. SCCR and arc flash ratings are always based on equipment being in original factory condition with proper maintenance to be valid. Yours now misses on both counts. So if something DOES go wrong and someone gets hurt, even a crappy lawyer can drive a lawsuit bus through that opening.
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Interesting (not really) how insurance didn't want to have to pay to replace equipment, yet will likely balk at paying later on when it fails and causes damages:(
 
petersonra said:
hard to know what he meant. but if they were never installed they may have been in the factory packaging which would probably have given pretty good protection even if the packaging got wet.
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to clarify, we have a pallet of panels in original packaging, and has been exposed to rain for a few weeks.
We also have a number of panelboard interiors left uncovered. They have had direct contact with rain, some more than others.
 
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