Transformer disconnect question

[grtule]

On a dry-type transformer located in a MCC, can you have the disconnect for the primary side of the transformer located directly above the transformer? I know it has to be within sight of the transformer, or be able to be locked out according to Article 450.14 in the NEC, but I was thinking that it can't be directly above the transformer. Can anyone clear this up? And if it can't be located above the transformer, where does it specify this in the NEC code?

 

[charlie b]

There is no restriction on where the disconnecting means is to be located. You can put it anywhere you like, and that includes directly above the transformer. May I ask why you are thinking that this might not be allowable?

Welcome to the forum.

 

[grtule]

I was thinking about the working space requirements like in 110.26A(3). Does the code consider the disconnect a working space since it is equipment associated with the electrical instillation, and if it does, then if the transformer extends out past the 6" allowed, wouldn't that be a violation? If that were a violation, if I were to mount the disconnect flush with the front of the transformer on unistrut, would that be allowed, or would that in turn extend the disconnect into the transformers working space?

 

[petersonra]

On a dry-type transformer located in a MCC, can you have the disconnect for the primary side of the transformer located directly above the transformer? I know it has to be within sight of the transformer, or be able to be locked out according to Article 450.14 in the NEC, but I was thinking that it can't be directly above the transformer. Can anyone clear this up? And if it can't be located above the transformer, where does it specify this in the NEC code?

The key words are in red.

The xfmr is part of the MCC assembly. The assembly itself requires the working space, not the parts contained within the assembly.

 

[DARUSA]

I was thinking about the working space requirements like in 110.26A(3). Does the code consider the disconnect a working space since it is equipment associated with the electrical instillation, and if it does, then if the transformer extends out past the 6" allowed, wouldn't that be a violation? If that were a violation, if I were to mount the disconnect flush with the front of the transformer on unistrut, would that be allowed, or would that in turn extend the disconnect into the transformers working space?

If it is a manufacture set-up I not see a violation but if you install it by you choice I will probably consider it as a code violation.


110.26 A (3) Height of Working Space. The work space shall be clear and extend from the grade, floor, or platform to the height required by 110.26(E). Within the height requirements of this section, other equipment that is associated with the electrical installation and is located above or below the electrical equipment shall be permitted to extend not more than 150 mm (6 in.) beyond the front of the electrical equipment.