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200V motor on 208?

Ox

Diamond
Joined
Aug 27, 2002
Location
Northwest Ohio
I bought a compressor last summer that had 200V -3 wire only motors on it. They pulled too many amps on my 240V, which I thought seemed odd, but I see in another thread that a guy had the same issue, and solved his issue by installing a tranformer to get his 240 down to 200. But his last post there was that he had just finished the install and apparently it worked at that time, and he hasn't mentioned any issues since, but I see that he hasn't been logged on in a few months now, so can't really ask him if that still is going well. (I suspect it is since he hasn't said)



It was mentioned in my shop thread that this motor is super for VFD systems, but that's not how this compressor was set up. It was built for upstate NY (Syracuse) and I don't know what V they run there.

Also was mentioned in the other guy's thread was that this motor may have been built to work with Jap 200 and Yank 208 in one design.

But this motor is 3 wire only. Are most 208 motors not made to take 480 as well? Are we getting to a point where we will have 208 motors and 480 motors, and they are not 9 wire changeable?


Would this motor work properly on 208?
I have a guy that is interested in buying them (2) for his grain augers and he is on 208, but we're not 100% sure if this would be the right application or not.

???


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Think Snow Eh!
Ox
 
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I gave 4 Quincy recips labeled explosion proof 200v running fine on 208 ( 213 measured ), my bandsaws are 240 and mostly run fine on the 208 though once in a while the HEM starts at half speed and needs restarted.
 
The 208 is only 4% higher than marked. That would not ever be an issue. "Generally", you can go to 10% high for UL marked equipment, including motors.

Also, your motor has a 1.13 "service factor". That is essentially an added "overload factor" and will account for extra heating due to overload, or higher mains voltage.

So there are two reasons for it to be fine in the case of your motor.
 
I understand the name plate is right there, but I have replaced it with a new motor that is labeled as "208-230/460" .

So, I guess I wonder why this wouldn't have been rated as "200-208" ???

Could be the difference in just Baldor or US Motor?

The 3 wire thing kind'a had me ??? and then CatMan said that it was used frequently on VF drives, just made me wonder if there was any reason that this wasn't a normal motor, or if it was built specifically for 208, yet didn't have that on the label?

My guy wants to use this at the top of his grain leg, and doesn't want to huff it all the way up there, and then find out that it doesn't work next fall when he doesn't have time to dink with such things.


I called our local motor rebuilder and the official answer is that 208 would be too much for it.
Of course, I have been feeding 240 to the 208-230 motor that I got from him for a few years by now, and all is right with the world.

???


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I am Ox and I approve this post!
 
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So I just called Quincy Compressor and asked Tech Support what the application was that they would have put this 200V motor on, and he said that they use that motor for 208 applications.

Guess I should'a started there... :o

So I guess this isn't near the red-headed step child that I originally thought.


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Think Snow Eh!
Ox
 
I believe the US/Canada likes to rate motors for a slightly lower voltage than the supply voltage. E.g. 230V motor on 240V supply, 460V motor on 480V supply, 575V motor on 600V supply.

Using a 230V (240V) motor on a 208V supply is possible, but you lose the service factor and may have to apply a derate.

I assume a 200V motor is therefore something specifically designed for 208V use.
 
Have 208 3 phase?
If not is a replacement motor cheaper than a transformer in the used market?
Not to mention that a drop down or buck/boost draws power ($) when the compressor is not working.
(They do make a nice spot to keep the coffee cup warm)
Bob
 
Let me try to clarify a few things.

In the power industry system utilization voltages are 4160/2400/600/480/240/208/120. Motor voltages are typically 4000/2300/575/460/230/200/115. I may have missed some. The motor voltages are approximately 4% lower than system utilization voltages because voltage drop in the motor leads is assumed.

As stated, motor ratings can usually tolerate a +/- 10% voltage. If you exceed 10% above rated, magnetic saturation can occur and amps can go up.

A motor is a torque matching device. For a given load, increasing motor voltage lowers the amps unless you hit magnetic saturation. Some saturation can be tolerated (if amps only go up a little bit) but high saturation can cause the amps to be unacceptable. Amps go up with a low voltage.

It is a myth that service factor allows you to run in an overload situation. Can you get away with it - yes, but that is not the intent. Most industrial motors of this size can tolerate an awful lot of abuse before being hurt. The service factor is intended to address de-rating from power quality issues. Power quality issues include low voltage, voltage imbalance, current imbalance, harmonics, etc. It would not normally address over-voltage above 10% of rated because that would be an abnormal condition and saturation cannot be predicted without looking specifically at the motor in question. It does not take much voltage imbalance to use up all of the service factor of the motor. 2-3% and you are way past the service factor de-rating. Somewhere I have a presentation I used to give on the actual numbers, but from memory I think about 1 1/2% voltage imbalance uses up the 15% of service factor, on top of that you have other de-rating going on.

You have a motor that is designed to be run at 208 volts and can safely run at 220 volts. 240 volts is a crap shoot.
 
I have a guy that is interested in buying them (2) for his grain augers and he is on 208, but we're not 100% sure if this would be the right application or not.

???








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Think Snow Eh!
Ox
You have a DP enclosure (drip proof) which is an open motor. I would not be putting that anywhere near a grain application. By code it could be a classified area, but I don't know.
 
200V is the rated voltage for a 208V supply, the 208V rating has been replaced by 200V for a number of years now on electric motors.
 
You have a DP enclosure (drip proof) which is an open motor. I would not be putting that anywhere near a grain application. By code it could be a classified area, but I don't know.
I thought that I replied to this already:

I believe that he was planning on puting it up high, like on a cross-over auger up on top, so much less likely to be an issue, but I took that coment to heart and i have been trying to contact him since.

Since this was topped and deminding me, I willbe trying to ping him again.

Thank you for that comment!


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Think Snow Eh!
Ox
 








 
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