225.32

[chris kennedy]

I think I have a design issue here. I have a detached AC pad fed with a 400A 208V 3 wire feeder. This is slabbed directly into a 208delta/480y277 step up transformer. Slabbed out of the tranny are 2 conduits for the seconday to the saftey switches for the CU's. (plus of coarse the GEC)

EE showed no disco on the primary of this tranny and I did not catch this until connecting the conduits from the pad to the building today. Do I have a problem here?

This is a pic of the "structure:roll:" from the building serving it.

Thank you.

 

[infinity]

So basically you're saying that you think that you have a separate structure with no disconnecting means?

 

[chris kennedy]

So basically you're saying that you think that you have a separate structure with no disconnecting means?

Thats what I'm thinking, comes back to that insane def of structure in 100.

 

[benaround]

Thats what I'm thinking, comes back to that insane def of structure in 100.

Time to find out what the EI's interpertation is.

 

[chris kennedy]

No, its time to find out what you fine folks think.

 

[Dennis Alwon]

Well, IMO if that is not a separate structure then I am not sure what would be. I say yes- separate structure. Where would the disconnect for the trany normally be?

 

[chris kennedy]

Where would the disconnect for the trany normally be?

Thats a good question. I don't see where that is called out in the NEC.

 

[raider1]

Thats a good question. I don't see where that is called out in the NEC.

There is no requirement for a "disconnect" for a transformer in the NEC (Right now at least).

A transformer must have overcurrent protection on the promary side but that protection does not need to be within sight of the transformer.

Chris

 

[chris kennedy]

Well do you feel that "structure" requires a disco on the primary?

 

[raider1]

Well do you feel that "structure" requires a disco on the primary?

I feel this "structure" requires a disconnect in accordance with 225.31.

Chris

 

[chris kennedy]

I'll guess you didn't open your book. This install meets 225.31, but not 225.32.

Still looking for more opinions please.

 

[raider1]

I'll guess you didn't open your book. This install meets 225.31, but not 225.32.

Still looking for more opinions please.

No, the safety switches on the secondary side of the transformer do not meet the requirements of 225.31 or 225.32.

225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.

The conductors that supply the "structure" would be the primary conductors for the transformer and they don't have a disconnecting means.

Chris

 

[chris kennedy]

The conductors that supply the "structure" would be the primary conductors for the transformer and they don't have a disconnecting means.

Indeed they do, at MDP, 150' away on the other side of the building.

FWIW I agree that there should be a disco here, but at this point we a talking a great deal of expense to do it.

 

[Cow]

Washington state interprets within 15' of a building part of the same building I believe.

Oregon, you'd better have a disconnect. Our inspector has let some things slide here that were close, but he's cracking down now when the structure isn't actually attached.

 

[Dennis Alwon]

FWIW I agree that there should be a disco here, but at this point we a talking a great deal of expense to do it.

Can't you intercept the pipe in the trench where Al is and bring it up to a disco and then back down to join the pipe again?

 

[chris kennedy]

Can't you intercept the pipe in the trench where Al is and bring it up to a disco and then back down to join the pipe again?

Yes sir, thats why I'm asking now. Underground inspection Monday. I need to know if I should fire off a RFI to the EE before I backfill. In reference to Frank saying just ask the EI, well he will be out Monday to look at this. In all honesty, I have learned that feed back here is usually spot on where as the opinion of one induvidual (the EI) may not be the same as that of EI that comes for the final.

 

[Dennis Alwon]

Yes sir, thats why I'm asking now. Underground inspection Monday. I need to know if I should fire off a RFI to the EE before I backfill. In reference to Frank saying just ask the EI, well he will be out Monday to look at this. In all honesty, I have learned that feed back here is usually spot on where as the opinion of one induvidual (the EI) may not be the same as that of EI that comes for the final.

The problem is we can be right on target but the AHJ may see it another way. We all know that situation. Hope all goes well. Say hi to Al from his own private Fan Club. :grin: