Under-Voltage Motor Operation 1

[Beggar]

I have a processing plant in China with a range of motors, most in the 3 to 20 hp range but one that's 200 hp. Most are driving centrifugal fans. They run about 18 hours per day.

Recently we've seen our supply voltage drop to as low as 340 volts (as opposed to the 380 VAC motor ratings).

My question is what is the result of this? I've seen that the motor currents have fallen along with a reduction of airflow through the fans.

The performance issues are apparent; my primary concern is the potential for damage to the motors themselves.

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How much do YOU owe?

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[waross]

I imagined you looking over my shoulder as I wrote that, Keith.
Respectfully

 

[itsmoked]

Yeah, we sometimes start answering precise theoretical questions which may confuse the OP or others who are after the solution to the physical problem at hand. Sort of what I was doing with imok2. I never meant to suggest that screwing with PF would solve the "Chinese Fan Anomaly" but the OP could sure start thinking that way. So it was nice for you to underscore that.

Cheers! Happy Easter.

And hallelujah! I found the signature check box!
Or rather my son who glanced over my shoulder as I pasted in my signature for 500th time said, "why don't you find the signature function??" Ah, youth..

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[waross]

Happy Holiday Keith.
I think we are usually in agreement 99+% of the time. We do sometimes disagree on the exact value of the 4th significant digit.
It should be noted that that is mutual striving for accuracy, NOT argumentation!!
Respectfully

 

[imok2]

Well Waross I certainly didn't intend to bring up one of your pet peeves, as you can see I prefessed the question by stating that I wasn't an Electrical Engineer But being a teacher in another field I have a lot of curousity and I have a need to know ,what can I say :>)

 

[waross]

Hi imok2
No problem. You were asking and your question was valid considering your background.
If your activities lead you into the realm of electric motors, surf the Baldor Motor web site. Find the Cowern Papers. Mr. Cowern has a gift for explaining almost everything to do with an electric motor in a way that is technically accurate but without overwhelming the reader with techical jargon.
respectfully