3Pole Disconnect Switched used as 3Ph (in)/1Ph (out)

[RP. ENG]

Hi, is using a 3pole disconnect switch for 3phase in/1phase out system allowed by code?

I have an application where I am going to have a 3ph/4wire service coming from a utility 3ph transformer, going to a 3pole disconnect.
But I only needed a single phase out of that system, so I'm thinking using the 2Lines (output) of that disconnect and call it a day.

I don't really want to bring in a 200A 3phase panel (minimum of 36" height) just to feed one load.

I'm looking to use this SquareD disconnect D324NRB.

Thanks in advance!

 

[ptonsparky]

Sounds good from here.

Why not just a 1Ph if that was all you need?

 

[RP. ENG]

Sounds good from here.

Why not just a 1Ph if that was all you need?

The utility will not allow us to have a single-phase 3wire, from their 3phase transformer.
So they will give us 3phase-4wire. Normally I would put a 3phase panel to feed a single phase load, but i'm exploring option to get rid of a huge 3Ph Panel just to feed a 1-single phase load.

 

[ggunn]

The utility will not allow us to have a single-phase 3wire, from their 3phase transformer.
So they will give us 3phase-4wire. Normally I would put a 3phase panel to feed a single phase load, but i'm exploring option to get rid of a huge 3Ph Panel just to feed a 1-single phase load.

I don't know of anything in the NEC that says you must connect something to all three phases on the load side of a 3P switch if all three on the line side are connected to a source.

 

[Jraef]

The utility will not allow us to have a single-phase 3wire, from their 3phase transformer.
So they will give us 3phase-4wire. Normally I would put a 3phase panel to feed a single phase load, but i'm exploring option to get rid of a huge 3Ph Panel just to feed a 1-single phase load.

That to me sounds as though the utility does not like the idea of an unbalanced load. But really, not your problem...
So sure, you can only use 2 of the phases for your load.

 

[jim dungar]

UL listing would mean a multi-pole protective device has been tested with its possible pole combinations. However you may find situations where the preference is to use the outer two poles,so that is not a bad practice to adopt.