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VFD - Over Current Fault

hkim310

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I am getting an Over Current Fault on one of my VFD's for my blowers. The first time it happened, I just reset the VFD. But its now happened 3 times so I decided that there must be some issue with the blowers that this VFD is attached to. Any recommendations on how to troubleshoot this issue would be greatly appreciated!
 

Waxman

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things to check:

contactor for blower motor.

wiring inside jct box on motor ( i've had bad connections there before that were burnt )

never had a vfd go bad but i guess they could.

the way i troubleshoot is start at either end as well as check / / change the easy stuff first. for example checking the wire nut connections inside the motor jct box is easy, as is swapping out a contactor for another.

good luck!
 

MEP001

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Load test the motors and check all wiring connections. Wiring at motors should be done with lugs, not wire nuts.

There's not usually a contactor in a VFD system.
 

wash4me

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Any chance someone changed the parameters? Go in and check that all of your motor data is entered correctly. Does it run awhile than do this? Does the vfd run more than one motor? Is there more than one vfd? If there are multiple units switch the wires from one vfd to another and see if the problem follows. There should be a screen where you can see the amps the unit is drawing in real time. Watch this screen as it accelerates and compare it to another one. Spin the fans by hand and see if there's a bearing noise or anything else unusual sounding between them. Ohm the motor leads to ground. Assuming the parameters are entered correctly the vfd is rarely wrong.
 

hkim310

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It turned out to be corrosion that had gotten on the wiring inside the junction box on the motor of one of the blowers. I really appreciate each of you all commenting and assisting me during the troubleshooting of this issue!
 

Jeff_L

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I was going to say check for corrosion inside the wiring - lol.

Glad you found it.
 

Waxman

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It turned out to be corrosion that had gotten on the wiring inside the junction box on the motor of one of the blowers. I really appreciate each of you all commenting and assisting me during the troubleshooting of this issue!
hey i said that! cool. i actually have learned something!
 
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