208-230 480 motor on 200v

[pault587]

I have designed a pumping system to go along with an air cooled chiller. I was told it was a 208V 3 phase unit. I ordered motors as such and they came 208-230/460V. The chiller unit nameplate says 200/3/60. These pumps are also variable volume (VFD controlled). The VFDs will be supplied by someone else who is doing the controls.

Is there any way to know if there is going to be any issues or code violations?

Is there anything I can or should put in the IOM to help select the VFD?

Is there an actual rating difference between 200V and 208V? I did some quick math and saw that phase to nuetral is 115V and 120V respectively and was wondering if 200 and 208 are basically the same like 115 and 120?

Thanks,
Paul

 

[steve66]

200 volts is the standard nameplate for motors intended to be connected to 208 volts.

I guess they assume there will be a little voltage drop on the feeders & branch circuits.

Steve

 

[jim dungar]

Is there an actual rating difference between 200V and 208V? I did some quick math and saw that phase to nuetral is 115V and 120V respectively and was wondering if 200 and 208 are basically the same like 115 and 120?

Yes,

The North American nominal voltages versus utilization (motor) voltages are:

120 - 115
208 - 200
240 - 230
480 - 460
600 - 575

 

[John Valdes]

200 volts is the standard nameplate for motors intended to be connected to 208 volts.

I guess they assume there will be a little voltage drop on the feeders & branch circuits.

Steve

The standard is 120/208/240/460. Just recently in the last few years motor manufacturers have started to include 208 on the nameplate. For example Baldor had a section in their catalog for 208 motors at one time. The reason was most if not all motors where listed as 240 not 208. There were concerns regarding operating 240 volt motors on 208 volts. With the mandated efficiency ratings the government had placed on manufacturers led to the newer nameplated motors. But every manufacturer will tell you not to run 240 volt motors on 208. The motor must be identified as operable at 208 volts on the nameplate. I have witnessed several warranty issues due to using the lower voltage. Fortunately we now can buy 208 volt motors, usually nameplated 120/208/240 for single phase and 208/240/460 3 phase. However the connections are identical for 208 and 240.

Since your motors are going to be controlled by VFD's you have no concern. The VFD is easily programmed for the minimum and maximum voltage to hz ratio. Another words is the VFD can be programmed for a 200 volt motor.

If you are doing the wiring for the VFD's and motors, there are some things you should be aware of before you start.

 

[weressl]

Did this come across the way it did in my mind?

I don't know Jim, I am not a mindreader........