200 volt delta compressor motor

[Red Wiggler]

The Mech. Contractor on our job submitted an air compressor that has a 200 volt "Delta" wired motor. We are in a commercial building that has 120/208 volt Wye system.

I told them that they need to get a different motor for the compressor. The mech Contractor told me that we could wire it our 3 phase 208 Wye system.

Is this possible?

 

[augie47]

please await confirmation from one of our more knowledgable motor members, but if I recall correctly the motor could care less if the supply is delta or wye.

 

[nakulak]

is it a 208, 60hz motor ? => yes

you said 200v though. where did that come from ?

 

[markstg]

Yes it is possible, and Yes it is just fine.

 

[markstg]

is it a 208, 60hz motor ? => yes

you said 200v though. where did that come from ?

Some motors are rated 200V, although it is more common to see 208-230V ratings.

 

[Jraef]

The configuration of the supply, i.e. Y or Delta, has no relation to the internal motor winding configuration. All that matters is the voltage. Just forget he told you it's 200V Delta, that's a red herring. It's just 200V.

200V is called the "equipment voltage" rating, 208 is the "distribution voltage" rating. The equipment voltage rating is always lower than the distribution rating to allow for voltage drop in the motor circuit. This is perfectly normal and acceptable.

Other Equip. vs Dist. voltage ratings:
115V ===> 120V
230V ===> 240V
460V ===> 480V
575V ===> 600V

 

[Red Wiggler]

Thanks

Thanks

Thanks,

I talked to the compressor manufacturer and he also confirmed that the suppy voltage whether from a Delta system or from a Wye system makes no difference.

His concern was how close the voltage range was as required on the nameplate... as JRAEF mentioned before.

115 -- 120
230 -- 240 etc.

 

[Jraef]

NEMA motor design specs call for a minimum of +- 10% voltage as having no detrimental effect on motor performance or life. So for a 200V rated motor, it should be able to accept 180-220V. What a lot of motor mfrs do however is actually design the motor around 220V, then label it as 208 / 230V, which means it can accept 198 to 240V. But you are out of tolerance on those if your 240V line goes +5%, which is acceptable to the utility.