Transformer - minimum side clearance

[cppoly]

What's a good estimation for the minimum clearances you would need for a transformer for the primary and secondary conductors entering / leaving the sides, 12"?

 

[jim dungar]

You would need the radius of the raceway elbow, or the width of an LL or LR fitting.
I don't think I have never seen a transformer with sidewall clearance restrictions.

 

[powerpete69]

If you look at the spec sheet for said transformer, it will give you minimum clearance.
The spec sheet for a siemens dry type 150 KVA, 480 to 208/120V, 4.8% impedance that I am staring at right now states:
"Spacings between any ventilated enclosure panel and any adjacent wall shall be a minimum of 5 inches except when wall mounted using approved wall mounting kit"
Since the transformer typically sits on the ground and the panel feeding it and receiving it typically sit much higher, conduit or flexible conduit clearance distances usually aren't an issue.
So please ask for the spec sheet on your transformer. If you absolutely have to guess, I believe 6" would be a safe bet if your transformer is 150 KVA or below.
The NEC code book may have some additional comments, but I will let you or someone else chase after that.

 

[kwired]

If you look at the spec sheet for said transformer, it will give you minimum clearance.
The spec sheet for a siemens dry type 150 KVA, 480 to 208/120V, 4.8% impedance that I am staring at right now states:
"Spacings between any ventilated enclosure panel and any adjacent wall shall be a minimum of 5 inches except when wall mounted using approved wall mounting kit"
Since the transformer typically sits on the ground and the panel feeding it and receiving it typically sit much higher, conduit or flexible conduit clearance distances usually aren't an issue.
So please ask for the spec sheet on your transformer. If you absolutely have to guess, I believe 6" would be a safe bet if your transformer is 150 KVA or below.

The spacing you mentioned is for free air around the transformer for cooling, OP is asking about clearance to allow conductors to enter from a side wall.

Answer really depends on wiring method and size involved. Minimum air space needed around the unit may be greater than what is needed for some wiring methods.

 

[powerpete69]

See attached picture. In this setup you would just consider vertical clearances per conduit allowable bends.

 

[jim dungar]

"Spacings between any ventilated enclosure panel and any adjacent wall shall be a minimum of 5 inches except when wall mounted using approved wall mounting kit"

Where in that spec does it mention clearance for non-ventilated enclosure panels?

 

[powerpete69]

Where in that spec does it mention clearance for non-ventilated enclosure panels?

It reads as stated.

 

[cppoly]

Thanks, the picture helps give a better idea of spacing required.

 

[powerpete69]

Thanks, the picture helps give a better idea of spacing required.

I guess a picture really is worth a thousand words after all.

 

[infinity]

What's a good estimation for the minimum clearances you would need for a transformer for the primary and secondary conductors entering / leaving the sides, 12"?

12" would work for just about any FMC 90° connector.