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Power flex 40 hardware over current fault

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Yashaar Mohammed

Electrical
Jan 14, 2019
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ZA
Hi

Can anyone advise?

I have 2 motors which is rated at 0,75 kw each and 3 amp connected in series and a power flex 40 with a 6 amp max current rating.

The current limit setting on the drive is 6A.

The problem that I am experiencing is when the motor starts up to 70% it tripped with an F12 h/w over current fault, I measure the amps to be below 2.5A when it trips, I have replaced the motors and the drive .

Any further ideas

Thank you
 
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Are the motors in series? How did you even do that?

Or, are they in parallel? If so, were the 2.5 A measured at the motor or at the drive? If measured at motor, you may have 5 A in total. So, it should trip.

If you activated autotune with two motors connected, you will get problems. The drive expects one motor in such cases and the outcome could be just about anything. Use autotune only with one motor connected. If you need best dynamic performance - you may need to rethink. If standard performance is OK, then use scalar mode.



Gunnar Englund
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Half full - Half empty? I don't mind. It's what in it that counts.
 
Thank you for the reply.

The motors are actually connected in parallel

The run boost setting is at 8

We actually found the problem which was on one of the isolators which had water in the junction box. The isolator was blown. Once we replaced the isolator. The reading is now at 1.3A

Thank you very much for your help and insight
 
So basically, the VFD was finding a fault that you didn't know existed...

They are good at that.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
 
Thanks for letting us know. Easy to forget about such things when there are hundreds of parameters and other things to worry about.


Gunnar Englund
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
 
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