Panel with no main breaker

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jhsparky1

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Can I set a panel with MLO with a set of 3/0 conductors (tap from a gutter with 2 sets of 250 KM) after a 600 Amp main disconnect switch.
 

raider1

Senior Member
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Location
Logan, Utah
Can I set a panel with MLO with a set of 3/0 conductors (tap from a gutter with 2 sets of 250 KM) after a 600 Amp main disconnect switch.

First off how are you going to tap a parallel set of 250 Kcmil conductors with a single 3/0?

Second you would have to provided overcurrent protection for the tap conductors in accordance with one of the rules in 240.21(B).

Chris
 

Jljohnson

Senior Member
Location
Colorado
I'm going with "NO". You must protect the tap conductors or, more precisely, protect the (likey) 225 amp rated panel at no more than it's max ampacity. Quickest, easiest way is with a main breaker in the panel
 

charlie b

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Lockport, IL
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Quickest, easiest way is with a main breaker in the panel
But that does not address the first question that Chris asked in post #3.


There are two separate issues here. The first is how to connect the tap conductors. The second is how to protect the tap conductors and the panel itself.
 

Jljohnson

Senior Member
Location
Colorado
But that does not address the first question that Chris asked in post #3.

There are two separate issues here. The first is how to connect the tap conductors. The second is how to protect the tap conductors and the panel itself.

The OP did not ask how to make the tap connection at all Charlie. The methods are many, the 1st that comes to mind for me is a set of PDB's (Power Distribution blocks) in the gutter. That would be my preferred method. Split Bolts are always an option but I personally don't like them, given the other options available.
 

charlie b

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Location
Lockport, IL
Occupation
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The OP did not ask how to make the tap connection at all Charlie.
No. But the OP did describe an illegal way to do it. That was my point. I was not talking about the manner of making the connections. I was echoing Chris' comment about tapping a single conductor per phase into a feeder that has two conductors per phase.

 

Jljohnson

Senior Member
Location
Colorado
The OP did not make any mention of how he planned to do the tap but, after revisiting Chris' question, I see how it came into play on the discussion now.
Cheers,
 
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