Eaton SVX 9000

Well...let me try this....

Problem : When troubleshooting an existing SVX 9000; with the load ( submersible pump ) disconnected....we are reading the correct voltage on the input into the VFD and we are reading the correct voltage on the output of the VFD.

When we connect the load ( submersible pump ) onto the VFD; we are reading the correct voltage on the input side of the VFD...however;.....The output side of the VFD...Phase A is reading a steady voltage....Phase B is reading a steady voltage...BUT....Phase C is reading wandering voltage from 238 volts to 290 volts.

The error message on the screen reads "Output voltage".

Any ideas ? Thank you in advance for any ideas.

Try connecting to a spare motor and running it to see what you get.

Here is a guess on where to look. It might be a loose connection on the IGBT power module DC Buss. It could also be the IGBT module partially failing. Maybe a defective motor.

Thank you Sirs....The pump motor is brand new....I will try to locate an extra motor that I can utlize.

We have performed insulation tests on the wires to the pump motor and checked for obvious loose connections....

I am not comfortable delving into the interior of the VFD at this time.

It kinda sounds like there is no real diagnostic test that we could perform to check the VFD performance other than the manual and the basic troubleshooting we have done to date.

We have talked to an Eaton rep on the phone ...but not much help....he went strickly by the manual.

I do understand that...

Thank you again.

I'm guessing the provided mains power and the motor is 3-phase instead of single-phase, otherwise, dont try this test at all.
Maybe you could bypass the VFD altogether for test purposes only. Just temporarily disconnect the drive and then run the motor briefly with it connected to the incoming mains power. While running, check the amps on each phase with a clamp-on ammeter. The readings should be equal and near or less than nameplate rating. If everything checks ok, then replace the VFD drive.

Yep...Roger on it being 3 phase....just tried the floor pump....VFD did the same thing.

We have been running the 30 HP submersible straight off of the contactors / overloads for the last 3 days at the owners request....

Just ordered the new VFD....I am very grateful for the different ideas.....a man does this for 30 years and he needs to be sure he isn't missing something very simple.

I am very grateful.

Thank you