Breakers & Conductors

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John Valdes

John Valdes

Senior Member
Location
SC.
Occupation
Retired Electrician
I received a PM today from a new member. Why he picked me, I have no idea. But his question got me thinking.

A new industrial electrician finds in the plant or factory some wiring situations that look to be violations. In particular he finds conductors smaller than allowed for the breaker size.
He wanted to know if he needed to replace the conductors? He gave me very little info, so I could not give him a firm answer and directed him to post the issue here on the forum.

My question: All electrical equipment installed and operating. Must this new electrician re-pull new conductors (if found to be undersized) or are they grandfathered in?
Or can he just warn the company of the issues he feels need to be addressed, and be done with it?
 
John Valdes said:
I received a PM today from a new member. Why he picked me, I have no idea.
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You just happened to "online" at the time...I get them all the time...some I answer, some I suggest they post, some I just ignore :)

John Valdes said:
My question: All electrical equipment installed and operating. Must this new electrician re-pull new conductors (if found to be undersized) or are they grandfathered in?
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How do we know the conductors are, in fact, undersized?

I'm sure we all seen #12's under a 30A CB.


I hope you suggested to the OP to start a thread.
 
Let's see...

There is the view of "management" that if it works, don't fix it! Don't be running up needless expenses.

Then an engineer friend would say you are the expert and are responsible for the safety of others. You MUST point out the problem and insist it be fixed properly or quit your job. A professional responsibility thing.

Then there is the new employee thing and it might not be a good idea to be "making waves".

And then I was in this situation once. I pointed out the problem to management. They did not want to spend the $$. I let it be...
 
How do we know the conductors are, in fact, undersized?

How do we know the conductors are, in fact, undersized?

the 'as builts' for the manuf. plant that i manage maintenance for faces this dilema often. fortunately, i've been here long enough ('69) to remember most of the project dates. alot of 'as built' wiring still exists. It works, and was installed to code. it isn't fiscally responsible to bring every thing up to todays code and still turn a profit. if it has a problem or creates an unsafe condition, its replaced. there are also time when updates aren't feasible because of the space required for the new elec equip. i can tell that about 1/3 of the receptacles in the building are labled as no equip gnd if not more, but if we touch we then pull it. (iowa osha thing as of 8/07)
 
I would let them know there is a potential problem, maybe take some heat readings, verify current, etc. You know, make sure it's not a major problem waiting to happen. If everything is okay, and they don't want to fix it, let it be, if there is a problem and they don't want to fix it, make waves. Either way, make and keep a paper trial and CYA!

Edit to add: I think you started a post for him! :)

And, it may be a local ordinance thing, but if it is working fine, and there really isn't a problem, and they don't touch, change, alter, modify, look at wrong or do anything else with it, they don't have to bring it up to code. But if there is a problem, I think they do.
 
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In particular he finds conductors smaller than allowed for the breaker size.
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Smaller conductors than allowed isn't enough information to properly answer the question especially in an industrial situation. It's possible that the CB's are oversized to permit the starting of motors. This is permitted by the NEC so there may not be an issue at all.
 
They may not be undersized. Depends what they are feeding. If they are undersized then I'd let my superviser know and leave it at that unless it was a safety issue such as if the equipment fails someone could get hurt.
 
If I found that situation, and it was immediately and incontrovertibly clear that there was imminent danger, I would notify my superiors post haste and/or lock out. If it was not so clear, I would discreetly ampprobe and/or ir to gather evidence, and do my homework thoroughly before opening my mouth, and thence notify the appropriate persons noting in particular the level of danger possible (preferably by memo in writing so I was off the hook if something blew up by the time they got around to doing something if anything) . IMO you have by the nature of the license a fiduciary duty to notify the powers that be of potential hazards when you find them (JMSHO)
 
Without knowing the specifics (Wire AWG, breaker size, and the load), it's impossible to say whether it's a violation or not.

Finding a 12 THHN on a 30a breaker alone is not a violation. Maybe it's to a motor.
 
480sparky said:
Without knowing the specifics (Wire AWG, breaker size, and the load), it's impossible to say whether it's a violation or not.

Finding a 12 THHN on a 30a breaker alone is not a violation. Maybe it's to a motor.
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Even if its not what are chances it be ok ? Industrial ,just let it be,probly been ok for 10 years.#12 wont melt at 30.Long term might get brittle.
 
Jim W in Tampa said:
.........

....Let it melt then fix.
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I think, with your permission of course , I found my new motto :D
Let it melt ,..then fix it.. ...yeah I like it


Please tell me you are joking :-?
 
M. D. said:
I think, with your permission of course , I found my new motto :D
Let it melt ,..then fix it.. ...yeah I like it


Please tell me you are joking :-?
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Scrap is good money.OP will be out of job if he stirs too much.Nothing wrong with a good melt. LOL
 
Jim W in Tampa said:
Scrap is good money.OP will be out of job if he stirs too much.Nothing wrong with a good melt. LOL
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Oh brother, it is possible to point out a potential problem with out getting fired. It is part of doing a good job to look out for things like this.

If it is a 100 amp breaker with #12 then you have a problem , if it is a over sized breaker for motor start up, time to do your home work. Article 430. would be a good place to start.
 
Jim W in Tampa said:
#12 wont melt at 30.Long term might get brittle.
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That's the primary concern with conductor ampacity ratings: insulation damage.

That's where the fire hazard comes from. Remember, NFPA.
 
John Valdes said:
My question: All electrical equipment installed and operating. Must this new electrician re-pull new conductors (if found to be undersized) or are they grandfathered in?
Or can he just warn the company of the issues he feels need to be addressed, and be done with it?
Click to expand...

Granpa may not even come into play. He may be looking an installtion improperly done, or he may not be sure what he's looking at.....Hope he posts his concerns.

If he's a plant electrician, and if he has a valid concern, he should advise accordingly.

Do you have a sense from the PM that he has that grasp?
 
frizbeedog said:
Granpa may not even come into play. He may be looking an installtion improperly done, or he may not be sure what he's looking at.....Hope he posts his concerns.

If he's a plant electrician, and if he has a valid concern, he should advise accordingly.

Do you have a sense from the PM that he has that grasp?
Click to expand...

I told him to post his concerns as he did not give me enough information to make a call. I used welder and motor circuits as examples just as you guys have done. His PM would make me think he is somewhat experienced but his wording leads me to believe he is not in the US, or is not proficient in english.
I think we can drop it. I don't see him here.
 
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