75 KVA transformer clearance

[CaJourneyman]

My AHJ is calling my tranformer a seviceable piece of equipment and is requiring me to move it in order to obtain a 42" clearance. My argument is that it is not serviceable and 30" should be sufficient. It is in a very small electric room and the cost to move it will be substantial. What are some thoughts on the clearances in front of your transformer?

 

[Pierre C Belarge]

What voltages?
Is the transformer directly across from another piece of electrical equipment.

And...
Transformers do occasionally require testing while energized.

 

[CaJourneyman]

480/208, a ATS on the adjacent wall sticks out 4" into the working clearance, but is 30" away from the transformer

 

[CaJourneyman]

Due to the fact that there is a possibility of live testing, this would then be considered a serviceable piece of equipment??

 

[Rockyd]

possibility of live testing,

Read 110.26(A) . I think the inspector is mistaken in his call. What part of a transformer needs adjusting?

Edit to add - Might want to contact the manufacturer of the transformer to get documentation (to support your position) in preparing any commentary to this inspector trying to shut you down.

 

[Pierre C Belarge]

Maybe the voltage or current is not satisfactory and they will change/adjust the taps.

 

[CaJourneyman]

But what about examination as stated in 110.26 (A)?? Would a transformer be deemed as something to be examined?

 

[CaJourneyman]

The code says adustment while energized. You wouldnt adjust taps energized.

 

[Pierre C Belarge]

I wouldn't, but I have seen some crazy stuff before.

There are still reasons to test a transformer while it is energized, I would qualify transformers as part of the requirement for proper spacing as per 110.26

 

[charlie b]

My design drawings do not set aside working clearances for transformers. I leave at least 6 inches to the nearest wall, or to two walls if it is in a corner. Then I make sure that it is not within the working clearance of a panel or other enclosure. But I do not consider a transformer to be an item that is likely to require (any of the listed actions) while energized.

 

[weressl]

My AHJ is calling my tranformer a seviceable piece of equipment and is requiring me to move it in order to obtain a 42" clearance. My argument is that it is not serviceable and 30" should be sufficient. It is in a very small electric room and the cost to move it will be substantial. What are some thoughts on the clearances in front of your transformer?

Makes me wonder why shouldn't the Owner, EE or EC request the AHJ to review the design documents prior to construction?

IMO; a transformer does not require adjustment, service and repair while energized.

 

[whillis]

Usually there are no taps or connections at the rear of a transformer so I see no reason to space it further from the wall than that required for proper cooling. Is this transformer in an area where it may require frequent cleaning? That's the only reason I can think of for considering it a serviceable item.