I know it will work on 277 1phase but not sure of 240 1 phase..

 

a 265 rated unit will work fine with 277, but a 240v supply is too low, as it is on the cusp of 10% under nominal voltage. these units are popular in hotels, managed care facilities, etc...

 

I installed a leibert ahu that was 240 the power supply voltage was 277 .Had to use a transformer to buck the power down to 240 to make it work. This leaves me more confused.

 

The boost/buck transformer only carries a small percentage of the actual load.In this case 277-240 = 37 volts and the same percentage of amps. You would use a 32 volt to buck it down to 245 volts.
You take a 12/24 x120/240 or 16/32 x 120/240 transformer and add or subtract 12,16,24,32 volts from the original voltage. Square D and several other sites have charts to make size selection simpler.

 

Sometimes the 277V version of a fan coil is a 240 volt one shipped with a transformer.

I never wired one of those up myself wolf, what do you do about the ground wire?

Is is a grounding electrode conductor after the buck and boost?

 

Isn't 265v what they use in Canada?

 

265/460 or 277/480 is not very common in Canada

347/600 is more common on larger commercial projects where 120/208 is not practical

 

The buck/boost transformer does not have a grounded component.
Use the ground as you normally would.

For 277 to 240 volts, invert the drawing.

(attached picture thanks to the excellent ECN site)

 

One phase

265 Volt is one phase of 460 Volts. Very popular in enviromentally friendly buildings. You cannot use a 265 volt unit on a 240 supply. You will burn up transformers and contactor coils like crazy.

 

*

265 Volt is one phase of 460 Volts.

i think your wrong johny

one phase of 460 volts is 277 volts




.

 

277 is the common voltage for building lighting, derived from 460-480 as described above. For a 240 volt supply, do use a transformer.

I'm still wondering what a "wshp" might be.

 

water source heat pump

 

I think the term 460 is still around because that is how they rate motors