277v and 120v device without barrier.

[darekelec]

Will I get 380V difference in potential between devices every time or is there a phase combination that barrier will not be necessary?

Meaning if I choose corresponding windings of a transformer the voltage will be less than 150V between devices and no barrier is required.

Thank you.

 

[roger]

It is dependent on the phases but I would use a barrier anyways

 

[wwhitney]

With a delta-wye transformer, the phase angle between a 120V L-N and a 277V L-N will be 30 degrees, 150 degrees, or 270 degrees (-90 degrees).

So the voltage between the two ungrounded conductors will be 183V, 385V, or 301V.

Cheers, Wayne

 

[darekelec]

Voltage diffrence between devices should not exceed 300v (not 150V as I wrote in opening statement) so there is a combination of phases that would not mandate me to install a barrier.
Thank you