Disconnects for transformers

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horses

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Location
Bradenton, Florida
I have a 75 kva transformer that is located between 20-25 feet from either the panel that is feeding the primary side & the panel that is being fed on the secondary side. The panel on the secondary side has 225A main breaker panelboard on the secondary side. The primary side is being fed from a 3P 90A breaker.

The transformer is not in the same room, it is on the other side of a wall. The engineer did not show an actual disconnect on next to the transformer. I feel as if the transformer needs a disconnect within site of it on both the primary & secondary sides.

I dont see anywhere in 450-3 where they call out an exact location requirement for either the primary or the secondary. Any help will be greatly appreciated.
 
raider1

raider1

Senior Member
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Location
Logan, Utah
I agree with Greg.

The secondary protection requirements for transformers are located in section 240.21(C).

Chris
 
charlie b

charlie b

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Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Greg and Chris, I think you both missed the intent of the question. It is not about protecting anything, neither primary or secondary, neither transformer windings nor feeders. The question is about having a local (non-fused) disconnecting means (i.e., to protect a future maintenance person).

There is no such requirement. To be specific, unlike motors and motor controllers and air conditioners and perhaps some other stuff, there is no rule requiring a disconnecting means to be within sight of a transformer. If I were the engineer designing the system, I would not have put a local disconnect in the transformer's room, for either the primary or the secondary side.
 
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