Noisy VFD Setup

[walterwoj]

I have been getting my new-to-me Clausing-Colchester 15x48 Lathe running and have gotten around to wiring up the VFD. I have it wired up the most basic way for now and am trying to get the motor parameters set. It is a 10hp, 1760 rpm, 230v, 3-phase motor. I have set all the basic parameters and run the auto tune. now for the trouble!

The motor thumps! (bangs/knocks/etc) Now the motor was previously running on a static phase converter and I put new bearings in it a couple weeks ago. When I hit start the motor knocks with increasing frequency and whines like mad until it hit full frequency (60 hz) then knocks at high frequency while running. When the VFD stops (I have it set to disconnect when I hit stop) the motor whispers down to a stop. JI know the sound comes from the motor but the cause is the VFD.

I have tried resetting the VFD to factory settings but It seems to keep the autotuned settings and I don't know what to reset them to for factory default.

 

[markba633csi]

What brand/model of VFD? Have you input the motor parameters manually?
Disconnect when hitting stop? Need more info

 

[walterwoj]

What brand/model of VFD? Have you input the motor parameters manually?
Disconnect when hitting stop? Need more info

It is a Huanyang GT-7R5G-2, I input the parameters that the manual said to manually. There is an option for the VFD to not decelerate the motor when you tell it to stop and it lets the motor coast down under it's own power. When it's coasting the thumping goes away instantly. Also most of my testing has been no-load (belts off) but I have tried it with belts on and it's exactly the same. see attached for the motor specs. I've also verifie the motor is wired correctly internaly.

 

[walterwoj]

Since the support for the VFD asked me to record some audio for them I figured I would share it here.
View attachment motor sounds.mp3
Sent to support:

The first ~20 seconds is the motor going from 0 to 60hz in 15 seconds, then it runs for a few seconds, then I turned the motor off via the vfd and let it coast for 10 more seconds. You can hear a very distinct thumping/knocking noise when it is starting up and it gets louder the closer to full power it gets. The sound is still there but not as bad when idling at full speed. When I turn the VFD off the noise stops completely and the motor just whispers. I have verified the motor is wired correctly internally and I installed new bearings in it a couple weeks ago. I made the recording with on load on the motor (belts off) but the noises are very similar under load. When I had the VFD configured to decelerate the motor to a stop it made the same noise all the way to stop.

 

[markba633csi]

It may be an issue with the carrier frequency- I would try changing it. Are you sure the motor is ok? You could try it on the static converter
again (if you still have it) to rule out the motor
Other than that my gut feeling is that it may be a fault in one of the 3 VFD output drivers and the only solution is to return it

 

[Ulma Doctor]

Increase the carrier frequency to about 10KHz and see if the sound goes better

 

[walterwoj]

@Ulma Doctor I have tried that up to 12khz and it helps with the whine and a very small amount on the knocking. I backed it back down to 8 (it started at 5) as that was the best spot.

 

[Ulma Doctor]

Maybe there’s a slight misalignment of the bearings.
If you were to loosen the motor end cap retention hardware and gently tap the rotor back and forth a few times, then retighten the hardware, it could possibly reduce some of the knocking

 

[mksj]

Did the motor run OK on the static converter? You did not indicate what parameters you changed on the VFD, so it is not possible to determine if it is a VFD issue or a motor issue.
Set P0.00 = 1 sensorless vector mode
Set P0.03 = 60Hz
Set P0.04 = 60Hz
Set P0.11 = 3 seconds acceleration time. You may also need to change P8.00
Set P0.12 = 3 seconds braking time. You may also need to change P8.01
Set P0.14 = 8 or 10 khz
Set P0.15 = 2 AVR only valid under deceleration
Set P1.05 = 0 linear acceleration/deceleration
Set P1.06 = You can start with 1 but I would change this back to 0 and then adjust the braking time as needed.

Motor parameters to check
P2.01 = 7.5kW
P2.02 = 60Hz
P2.03 = 1760 RPM
P2.04 = 230V
P2.05 = 25.4A

Rerun auto-tune to determine the other motor values P0.16 =1. If the motor still has a knocking noise, then could be a defective VFD, in a few cases I have seen some motors not work well with VFDs, typically under acceleration.

 

[strantor]

I haven't heard anything that sounded exactly like that, but in the ballpark. I think one of your VFD output transistors might be bad so you're running on 2.5 phase instead of 3 phase.