Multiple (3) sources of power in the same panel

[wwhitney]

Are you talking about the 120% rule (where the power sources are connected to opposite ends of the panel busbars?

Any part of Article 705. My understanding of the OP's install is that any panelboard busses are each connected to only one source of supply.

Cheers, Wayne

 

[ggunn]

Are you talking about the 120% rule (where the power sources are connected to opposite ends of the panel busbars?

Yes; that's what 705.12(B)(2) in the 2017 NEC (it was moved to 705.12(B)(3)(3) in 2020) is about, and it has no relevance to the OP's question. This is what happens when one does a search of the NEC and quotes a section of it without considering the context of the quoted language. Article 705 is about parallel connected power supplies with the same voltage, e.g., PV systems interconnected with the electrical grid. The OP's question is about multiple sources with different voltages in the same panel.

 

[Jraef]

Woof rough day... sounds like someone had a base case of the Mondays...

Yes, so that mostly answers my question and I thought of a better way to word it. Since the disconnect will not be serving as branch circuit protection directly to any of these motors, I need not worry about HP rating of the disconnect and only typical load calculations as you stated?

OK, I am at my PC with time on my hands.
It's in Article 430.110, and yes, it is 115%, but there are caveats regarding HP ratings.
But if it is COMBINED loads, i.e. with heating equipment, then it must be 125% per 424.19 and/or 425.19.

 

[Jpflex]

I don't see how you could do this; a set of busbars can only be at one voltage. You could have 480/277V in the panel and a transformer to generate the 240V three phase with a center tap (high leg) to make the 240/120V, but I don't see how to get it all in a single panel.

A single big poopy dukey panel with partitions with isolated busses from high 3 phase to low single phase

 

[ggunn]

A single big poopy dukey panel with partitions with isolated busses from high 3 phase to low single phase

I googled "poopy dukey panel" and I did not get anything related to the question at hand. I did get a lot of references to... other stuff.

 

[petersonra]

My suggestion is to get three separate disconnect enclosures and bolt them together if you insist on this approach.

 

[drcampbell]

Have the two of you looked at the bigger picture? Would it be possible to consolidate all the 3ø loads on 480v?

 

[Jpflex]

I googled "poopy dukey panel" and I did not get anything related to the question at hand. I did get a lot of references to... other stuff.

lol well if they would stop making these phones change everything we type we wouldn’t have these issues. And I shouldn’t have to be suspicious and go back to what I wrote just to see if it’s been changed