Transformer Enclosure Splice

R

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
I have transformer where the secondary feeders go under slab. We need to create a new secondary feed and back feed the old secondary. .Is there a code that permits using the transformer enclosure as a splice or pass through so that we may reuse the existing in slab conduits to refeed the existing secondary panel?

Disconnect existing secondary conductors, feed new secondary conductors to a panel. from the new panel, send feeders from a circuit breaker back through the transformer enclosure and into the existing conduit.
 
i would say no.
using the transformer as a pass through would allow the power to bypass the transformer breaker and feed the circuit directly if there was an issue with the wire insulation and it shorts.
i cannot cite an exact code, but i would fail the installation.
philip
 
I can't think of a Code violation.
Personally, if I did it, I would want to permanently mark the transformer cautioning about a second power source.
 
augie47 said:
I can't think of a Code violation.
Personally, if I did it, I would want to permanently mark the transformer cautioning about a second power source.
Click to expand...
Technically, if I am understanding the OP correctly, the transformer's disconnect would still disconnect the feeder being run through it.

Though, I agree that it will be messy and more than likely create a wire space / fill issue. Kind of depends on the venting and where the splices / extra wire would end up.

If there is enough space for the transformer then I don't know why you wouldn't have enough space for a box + transformer just by shifting things up the wall or re-running the old feeder circuit and extending conduit up above the transformer.
 
Elect117 said:
Shift the transformer over and install a box where the conductors currently enter?
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No space to shift the transformer. I could raise it up to create space underneath, but it sits in a cutout with just enough room on the side to get a piece of flex. Its not sitting in an open room.
 
pwhite said:
i would say no.
using the transformer as a pass through would allow the power to bypass the transformer breaker and feed the circuit directly if there was an issue with the wire insulation and it shorts.
i cannot cite an exact code, but i would fail the installation.
philip
Click to expand...
If you can't cite a code you can't fail it don't be one of them.
 
AC/DC,
i would fail the install because of a previous issue just like this.
the conductors insulation was worn away / damaged and the lines were connected.
something went wrong and the only way they got the power off was to trip the disconnect to the transformer.
i was not there, but i heard about it from plant maintenance.
is it a code violation, i don't know.
i want everyone to go home the way they went to work. Safe and unharmed.
you see a lot and hear a lot of stories in 41 years of electrical work.
i stay on the side of caution. I'm not an inspector, i was in charge of the plant electrical system and flagged a lot
of proposed work due to questionable practices. everything went before upper management and i was rarely over ruled due to safety
concerns.
philip
 
Rock86 said:
I thought that too, but I wasn't going to argue it because it never goes well arguing with an inspector. (even though he is not my inspector.)
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Just my two cents- guys on this forum after reading many post have stated it’s are job to make sure the inspector actually site correct code- I now have no problem argue with them. When your right your right— if they go after you latter than you go after them
 
pwhite said:
AC/DC,
i would fail the install because of a previous issue just like this.
the conductors insulation was worn away / damaged and the lines were connected.
something went wrong and the only way they got the power off was to trip the disconnect to the transformer.
i was not there, but i heard about it from plant maintenance.
is it a code violation, i don't know.
i want everyone to go home the way they went to work. Safe and unharmed.
you see a lot and hear a lot of stories in 41 years of electrical work.
i stay on the side of caution. I'm not an inspector, i was in charge of the plant electrical system and flagged a lot
of proposed work due to questionable practices. everything went before upper management and i was rarely over ruled due to safety
concerns.
philip
Click to expand...
That’s installers issue many way to verify if system is safe- if a code violation did not happen then it’s legal I would take that to the state board
I understand your point but I also have to account what’s best for my customers and what’s best for me- if they can’t afford some drastic change and I can legally do it then I’ll do it

Even if they can afford it’s there choice I can’t force them if it’s legal

And if you have power over with the plant, then I guess your decision rules since you’re technically the foreman I guess I don’t know how that chain of command works, but if you were a state inspector, I’d fight it

Just my opinion
 
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What about double tapping the transformer?
AC\DC said:
Just my two cents- guys on this forum after reading many post have stated it’s are job to make sure the inspector actually site correct code- I now have no problem argue with them. When your right your right— if they go after you latter than you go after them
Click to expand...
Oh i agree with you here, but I don't want to blow up the thread with an argument. In the field you point if valid. ;)
 
AC\DC,
i agree with what you are saying.
i will raise a flag to alert everyone to issues i deem as cautionary / unsafe.
that will go up the chain to the plant engineer & safety for review.
i explain my reason for caution, most of the time they agree, other times they explain why i am wrong.
i am ok with that. i don't know the code as well as i should.
as an electrician/ engineer, i had rather raise a flag over something i have concerns about and be proven wrong
than to let it pass and someone get injured. that's just the way i am.
if i offend anyone here for my posts, i do apologize, i am still learning even after all these years.
philip
 
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