200 vac 3ph motor

[EMSGuy]

Greetings,
I am currently on a site where the compressor manufacturer has stated he cannot meet the design voltage, which is 208vac 60hz 3Ph and wishes to substitute a 200 vac 60hz 3ph motor for our compressors. This is a Canadian installation and I am not familiar with 200vac as a standard. Am I behind the times on something? Or is this a common voltage in the U.S.
Appreciate some input

 

[davidbeach]

Motors intended for use on 208V systems are 200V motors, just like motors intended for use on 480V systems are 460V motors and those for 240V systems are 230V motors.

 

[waross]

I agree with davidbeach. 207 volts is the lower limit of the 10% tolerance for under voltage on 230 volt rated motors. Using them on 208 volts, as was done for years, was pushing the envelope. The comparatively new rating of 200 volts is appropriate for 208 volt systems.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[jraef]

Yep. 208V is the "system voltage", 200V is the "utilization voltage" to which the motor is designed.

Some manufacturers use a motor that is name plated as "200-240V" and they will show two separate current ratings: one at 200V and the other at 240V. What they really do is wind it for 220V and the tolerance takes it from 198V (220 - 10%) to 242V (220 + 10%). But not all manufacturers offer this and your supplier obviously does not use one that does, choosing instead to provide a true 200V motor. It's probably a little better that way.

 

[EMSGuy]

Thanks for the assistance guys- being on the fringe of the business sometimes leaves a gap in the old knowledge base.
This site has been a valuable source for me over the time I have used it and I appreciate the help.
emsguy

 

[Sulzer1]

Hi;
I have been in the electrical engineering field all my life and for the last 33 years in Canada and I have never heard of any 200 Volt supplies in the country. 220 Volt, 3 phase is our countrywide standard!!!!

 

[dpc]

On a 208 V system, the proper motor voltage is 200 V. They are available, but might require a special order. There is a column in the NEC motor FLA table 430.250 for 200 V motors.

Many motors are rated "208-230/460". So called "triple-rated" motor. These can be trouble at 208V. They will RUN at 208V, but will not meet any of the specs for horsepower, service factor, efficiency, power factor, etc. And if the voltage drops much below 208 V, all bets are off. This is definitely not to be considered an equal substitute for a motor nameplated at 200 V.

 

[EMSGuy]

Sulzer1 (Marine/Ocean) 6 Feb 08 13:16
Hi;
I have been in the electrical engineering field all my life and for the last 33 years in Canada and I have never heard of any 200 Volt supplies in the country. 220 Volt, 3 phase is our countrywide standard!!!!

Actually Sulzer I have been looking into this with the manufacturers and also found that 200 vac motors are listed under Table 44 (3 phase motors)of the Ontario Electrical Code -23rd edition. It makes more sense efficiency wise to order a 200 vac motor for our application compared to a 230/240 vac motor.Many industrial commercial applications are 208 3 phase here in Ontario anyways

 

[jraef]

As a US citizen who lived in Seattle and jumped the border quite a bit, my experience in Canada is that there is no standard voltage. Everyone thinks it's 600V, but all the lumber mills I ever worked on in BC and Alberta were 480V, a lot of the commercial/light industrial buildings were 208V instead of 600V, and I never once ran into 220V 3 phase (but then again, I did mostly industrial work up there).

 

[EMSGuy]

jraef I agree - although most industrial/ institutional plants in Ontario have 600/208 3ph.

 

[waross]

Hi jraef
When the standard voltage in BC was changed from 480 to 600, the utility stopped supplying 480 volts for new installations. Industrial installations had the choice of utility supplied transformers or a high voltage service and their own transformer bank. Many industrial plants opted for 480 volts with their own transformers and a slightly cheaper energy tariff.
Some smaller industrial plants used a combination service entrance and distribution panel that incorporated an internal open delta autotransformer rated 600:480 volts.
It worked well but gave a neutral shift so that line to neutral loads were not feasible. Institutional and commercial installations accepted 600 volts much sooner than the industrial sector.
Respectfully

Bill
--------------------
"Why not the best?"
Jimmy Carter