New feeder from transformer

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gsmeal

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wondering if there are any code concerns with this;
I need to create another 3phase 208V connection. At present from the main panel box(480V 3phase) there is a feeder through a 200amp breaker going to a stand alone 75KVA 480V/208V 3phase transformer. This feeds a 225amp breaker box mounted on the wall next to the transformer which feeds a panel box in the utility room about 130 feet away.
My question: can I install another breaker box at 60 amps and connect directly to the secondary of the transformer for the feed?
 
I'm having trouble understanding what you wish to acommplish, Are you an electrician??

Transfromer secondary taps are covered in 240.21 (C)
NEC

Charlie
 
Maybe.

The transformer has a rated output 208 amps at 208 volts..

You are allowed to protect it at 125% or 260 amps of OCP.

If you had a single OCPD table 450.3(B) Note 1 allows moving up to the next standard OCP size.

So that would be a 300 amp OCP.

Note 2 says the OCP can consist of up to six OCPDs with a total not exceeding that of a single OCPD.

So your 60 amp and your 225 amp total 285 and IMO that complies with the wording of the table notes.

What is the actual load being placed on the transformer.

The actual load can not exceed the transformers 208 amp rating.
 
This is an addition of an AC unit in my shop and the contractor said that the feed has to come from the panel box in the utility room. My question to him was why can't we tap off the transformers secondary, plenty of room being a 75Kva, but he said it does not meet code. I can't seem to find where it goes against code in 240.21.He stated because of the distance between the wall mounted breaker and the panel box in the utility room. But this would be a different circuit with a direct tap from the transformer.
 
It is not against code to have multiple OCPDs on a transformer secondary.

The OCPDs will need to be grouped and both have to be located close to the transformer to meet the distance requirements in 240.
 
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