Yaskasawa 1000 VFD

I have / had a a PLC controlling a Yasakawa 1000 VF down to 16 hz .


The VFD continues to give me a OV fault (over Voltage)

The load is CONSTANT. The fault is intermittent. You can see up to 15 hours of run time before the fault occurs. (we are not ramping up and down and it's not on startup or shut down.

I removed the PLC and am now running it as a stand alone drive at a static speed and the problem persist.

Yaskawa tech support says it's "motor issue, wiring or frequency within the building"

The equipment manufacturer assure me the motor is not limited by the low speed. and the motor has a Inverter Duty rate of 10-90 HZ So I eliminated that.

I have temp wired directly between the output of the drive to the motor to eliminate any wiring issues.


The motor is a Bodine Motor "pacesetter" Inverter duty motor wired for 460.

And at 16 HZ you are getting 460 in and 120-130 ish volts out, which matches my math as appropriate (460/60 = 7.60) ------ 16 hz X 7.6=121.6 volts

Any ideas?

Isn't 0V an undervoltage fault? 15 hours at 16 Hertz before getting a fault? What's the HP?
Maybe motor getting hot. Integral fan won't do anything at 16 Hertz. Check wiring in peckerhead. Might be one lead is intermittent. Does it have an overtemp cutout?

keithkyll said:

Isn't 0V an undervoltage fault? 15 hours at 16 Hertz before getting a fault? What's the HP?
Maybe motor getting hot. Integral fan won't do anything at 16 Hertz. Check wiring in peckerhead. Might be one lead is intermittent. Does it have an overtemp cutout?

Click to expand...

I thought that too, but the motor is an Inverter rated motor and is lists a "INVERTER DUTY RATING" of 10 to 90 HZ and a RPM rating of .25-4.4RPM and I'm within that.

It's 1/6 HP motor.

Does the drive have an income line reactor?

If I'm not mistaken you can get OV faults when the load overhauls the motor regardless of the speed.

What is the DC bus voltage doing? Overvoltage faults in my experience mean high DC bus voltage. Also, compare what the VFD displays for DC Bus volts with what you can (safely) measure with a good instrument.

I once had a VFD that had a problem measuring its own BUS voltage and would report it incorrectly and fault. It was a small cheap drive so we simply replaced it.

"Inverter Duty" doesn't mean it you can run without a fan. Probably doesn't matter much at 1/6 HP. There's enough metal to dissipate heat.

15 hours makes me lean towards heat related. You said "up to 15 hours... ". Is it always a long time? Check VFD fan and heatsink fins.

keithkyll said:

"Inverter Duty" doesn't mean it you can run without a fan. Probably doesn't matter much at 1/6 HP. There's enough metal to dissipate heat.

15 hours makes me lean towards heat related. You said "up to 15 hours... ". Is it always a long time? Check VFD fan and heatsink fins.

Click to expand...

15 hours is the max , and got that after temping in the wiring between the output side and the motor

How old is the drive? As they age, the capacitors degrade to the point nuisance trips become an issue, both under and over voltage.
Input Line Reactor for noise spikes?
EMI/RFI filter connected to good ground?
277v each input phase to ground?
Overhauling load?
Dynamic Brake Resistor?

Lots of variables...

OV means Over Voltage on the DC bus. 99% of the time that is the result of the LOAD causing regeneration into the DC bus because it is overhauling, meaning the load is causing the motor to be spun faster than the VFD is telling it to run. The cure for that is to find out why that load is being allowed to overhaul, or if that can't be fixed, you have to add a Dynamic Braking Resistor to the drive so that the regen energy can be bled off as heat.

On rare occasions you can have some sort of capacitive resonance between the VFD bus caps and some sort of line side activity, such as repeated line noise spikes or surges, or PFC caps somewhere else in the facility. Line reactors can help dampen the spikes if that's what it is (and are a good idea anyway).

you shouldn't need any reactors with a V1000
and you should be able to run it own to below 6Hz. I have run them down that low without problems.
week or bad buss caps can cause an over voltage fault they don't filter the buss enough when week
try changing out the V1000
also make sure that you don't have an overhauling load at some point that will cause the buss voltage to go high
also you could try adding a brake resistor to the drive if you are getting an overhauling load it take care of it.
also make sure you line voltage isn't floating up to high

Kirk,

What type of load is the motor driving?

A few things to check would be.

Monitor incoming power.

I would check is the motor or wiring for short-circuit, I’ve seen several times where electricians missed a bad wire installation or even a motor going bad. Meg out circuit by disconnecting the motor wiring from the drive than meg out the wiring and motor at the same time

Check E1-01: Input Voltage Setting (been there seen this one before)
For 460V models approximately 820 VDC across DC bus is the overvoltage fault. As stated by OkiePC (You can also look at the DC bus voltage and compare it to the value in U1-07 (Monitor) this is the DC bus voltage as seen by the drive, I like to with in 20 vdc of actual from meter. If the discrepancy is more than this could also be the problem.)

Also are you running in open loop vector, try switching to V/F Mode.

Another thing that comes to mind is if you are using encoder feedback in a closed loop control system, induced noise could be causing unstable output waveform.

Hope This Helps
Tom

jraef said:

OV means Over Voltage on the DC bus. 99% of the time that is the result of the LOAD causing regeneration into the DC bus because it is overhauling, meaning the load is causing the motor to be spun faster than the VFD is telling it to run. The cure for that is to find out why that load is being allowed to overhaul, or if that can't be fixed, you have to add a Dynamic Braking Resistor to the drive so that the regen energy can be bled off as heat.

On rare occasions you can have some sort of capacitive resonance between the VFD bus caps and some sort of line side activity, such as repeated line noise spikes or surges, or PFC caps somewhere else in the facility. Line reactors can help dampen the spikes if that's what it is (and are a good idea anyway).

Click to expand...

I second this response. We had this problem a while back with a Yaskawa V1000. Someone had fingered the drive on the conveyor motor upstream of the suspect conveyor motor/drive, so that when the product came upon that section of conveyor, it was travelling faster than the downstream conveyor was running, causing regeneration and an OV fault.

Seems like I have to say this a lot but check the 460V source for floating delta. If it is floating, stop searching and buy a small drive isolation transformer. Arrange the secondary for wye and ground the center point at or near the same ground as the drive.

If your power is floating, its a pretty sure bet that this will fix it.

I'm interested to see what the final solution for this problem is. But my 2 cents.

Is this a new installation or is it an old installation that is suddenly acting up?

You seem to be running this motor all the time or at least for extended periods and you say the load is constant. What percent of full load is the load? How do you know the load is constant? I mean the most obvious solution is that the load is overhauling, but if the load is constant why would it suddenly overhaul? What is the load? Why was the system designed to run the motor at slow speed? Do you need at some point to increase speed?

This is a puzzle and maybe we can ask you some questions that maybe you didn't think of and that will give you a eureka moment.