Transformer disconncet Requirements

[rookie4now]

We have a 1-line for an upcoming instillation that shows a 100A 3P breaker feeding a 112Kva transformer, then after the transformer is a non-fused disconnect and then a 100a 3p panel that has 3 3a 3p breakers for the equipment. The distance between the panel that is supplying power and the transformer is about 50' and is in another room. Won't we be required to put a non-fused disconnect on the supply side of the transformer AT the transformer? Also, shouldn't the disconnect between the transformer and the sub panel be fused? I suppose alternatively we could use a main breaker in the sub panel.

Also, any code references would be appreciated. I looked at 450 and couldn't find the requirements.

Thanks

 

[iwire]

You can either provide a disconnect within sight of the transformer or label the transformer with the location of the disconnect with a lockout device.

450.14 Disconnecting Means. Transformers, other than
Class 2 or Class 3 transformers, shall have a disconnecting
means located either in sight of the transformer or in
a remote location. Where located in a remote location,
the disconnecting means shall be lockable, and the location
shall be field marked on the transformer.

As far as the secondary side the NEC is likely going to require a single set of fuses or a single breaker withing 10' of conductor length from the transformer.

 

[rookie4now]

You can either provide a disconnect within sight of the transformer or label the transformer with the location of the disconnect with a lockout device.



As far as the secondary side the NEC is likely going to require a single set of fuses or a single breaker withing 10' of conductor length from the transformer.

Excellent, thank you. And thanks for the code reference too.