Mitsubishi F500 series inverter

F540 22KW

Cor, I've struggled with this.

Can anyone tell me what I am missing.

Customer bought a 2nd hand inverter as above (old one blew up) - asked me to fit it.



The operation is fairly simple;

Its for a centrifuge that acts like a huge spin dryer. 5 ton of wet yarn is placed into it and it is spun until all the water is gone (5 minutes)

All I need is 1 signal to STF (fwd) and I have linked this to the High speed terminal

So the operation is Ramp up for 30 seconds to 40HZ (a 22KW 400V standard motor)



Being second hand, I reset all held parameters to factory setting.

I have set all the ones I thought I needed (but I never found anywhere to tell the inverter what motor was connected or details from the name plate)

Nor did I find an autotune or anything like that.

I tried jog in local mode (5HZ) to check fwd direction and it ran perfectly

I then tried remote for ramp up to 40 HZ in 30 seconds and it struggled to start,

The display showed the HZ slowly moving up but at about 12HZ the motor was making nasty noises and tripped the over current (the motor was moving but struggling)

Any help with paraneters



Thank you

Are you sure its an F540, not an A540 - if so they are only designed for variable torque (most fans / centrifugal pumps) - they are effectively light duty (120% OL for 60s and 150% for 3s) not the normal duty of the A series of 150% for 60s and 200% for 3s

Pr 80(motor capacity) and 81 (#poles) don't exist in the F drive (volts/hz only) so no motor tuning

Pr 14 (load pattern) should be 0 not 1 (which it is by default as this drive is intended for variable torque loads not constant torque)

You can increase the torque boost for the start by increasing Pr 0

By default Pr 22 (stall prevention) will be 120% - you can increase that if you think you're being limited

Forgot to add - if you still have the old one and the control board is ok (blew up would indicate power components so it may be), you can power the control board by putting single phase 400V on R1 and S1 (remove the jumpers), then you can us the PU to view the params that were in use

@raffles covered it all.

If it jogged unloaded, your boost is likely a bit low. I'd jack up Pr22 to 200% on a centrifuge type of load.

I would start the boost at 5%, then try a start
try 6% if it does not start
then 7% .. etc

If you get in the 10% range you will get cogging .. rough operation .. not smooth at all.. but it may not be an issue when loaded.

If you get to 20% boost, you won't like how it runs even if it does run. But you may need it.

I have run up to 40% boost, just to see what happens. It shakes the motor and any load connected, like a servo controller that is tuned too fast. Accelerates, then decelerates, then accelerates. Very hard on a gear box. It makes the belts squeak or chirp. I was surprised it allowed the boost that high.

Thanks very much.
I'll try these things monday.
Didn't like the news i was playing with the lite version of the inverter.
I'll keep you posted.

Ronnie Sullivan said:

Didn't like the news i was playing with the lite version of the inverter.

Click to expand...

Mitsubishi light is a lot of others normal, with their normal being a lot of others heavy, but that being said with the age of this VFD and the lack of any form of control other than v/hz it's never going to be fun.

How did you make out?

Not so good.
I got it to speed but it complained all the way up - mainly OL
I could only set it to 150% (max allowed)
It then locked out with a variety of faults.. A few regen faults.

They were lucky as the ebay seller will take it back.
They are having a new one delivered tomorrow.

I got a Control Techniques 22KW heavy duty inverter to play with.
Isn't our job much easier when you get the right tools?

I uncoupled the motor to do a rotation tune and a few tweaks later - it ran beautifully.

Thanks for all your help

A big problem with used inverters on Fleabay and the like is that the sellers don’t tell you how long the drive has been sitting unused on a shelf (or they know and omit that or even lie about it). So when you get it and energize it without reforming the capacitors, one or more of them get damaged, which if it doesn’t explode, at the very least affects the bus ripple and the transistors on the output can’t handle that. You are lucky the he took it back.

jraef said:

energize it without reforming the capacitors

Click to expand...

A very good point, I know Mitsubishi say after 2 years any VFD should be reformed. How long has that spare been on the shelf.....

When you power up a drive on the bench, reforming the capacitors 'can be' as easy as using a variac and raising the voltage on a pair of input terminals by stages.

In most cases, you will heat up the pre-charge resistor really badly doing that. It is intended to pass current to charge up the capacitors until the bus voltage is high enough to power up the electronics, which close a bypass contactor on the resistor. Normally under 1 second.

I have done a full wave bridge on the output of a variac, to the + and - bus connections ... to gently bring the voltage on the bus up a few volts at a time. I do this on damaged drives routinely, just in case there was damage to a capacitor. When the current into the bus is stable for 1 minute, I raise the voltage between 5% and 10% of rated. It's slow, but I have not had a capacitor blow up.

If your first power up of the drive is when it is installed, reforming the capacitors is much more challenging. You can still use the variac, with the power to the drive locked out and tagged out, and the output terminals on the drive disconnected from the wires going to the motor. But I have not experienced this in the field. Everyone is in too much of a rush. No one puts enough time in their schedule to commission properly, much less power up the drive gently. I have a plan written up, but have never had enough time to actually do it.

Our spare drives, in our warehouse, have a 2 year Preventive Maintenance Task to do the capacitor reforming. It takes about 2 weeks for one electrician to pull each of them out of the crates, power them up, record the currents into the drive (10% steps on voltage), wait for the drives to discharge, crate them up again, and get them stored in the correct location before starting again with the next one.