single phase panel from a 3-phase fused disconnect?

[donw]

Hi. I have a tennant improvement that has existing 3-phase SES with class "T" pullout fuses. I need to feed a single phase (3-wire, 208v,120v) panel for x-ray equipment. Is there a problem with just not using one of the phases of the disconnect/fuse?
Thanks,
Don

 

[jim dungar]

There is no problem with only using two poles of a three pole device.

In fact, Square D does not make 2-wire fused 480V fused safety switches, their catalog says you need to use a 3-wire device instead.

 

[donw]

Thanks Jim!

 

[charlie b]

Are you certain the specs for the x-ray call for (or at least declare to be acceptable) a 208/120 volt single phase supply? Most single phase, dual voltage equipment will call for 240/120, and will not operate properly with 208V

 

[donw]

Charlie, the x-ray generator is 240v 1-phase, but it has a factory-supplied boost transformer.