Gunsmithing Anyone have experience with Mitsubishi D720 series vfd setup?

[jonaddis84]

Having trouble getting this thing working on my new lathe. Colchester 3hp. The vfd is the model designed for single phase in. My input voltage is 240 line to line.

I've gotten it to turn on and at first it was cranking out 280v on each of the 3 legs. I turned down the motor voltage parameter to 170 and now it's at like 236v. The light on the lathe is on, but when I turn the spindle on it turns a few degrees and quits. No faults on the drive. Coolant pump seems to work.

The spindle motor worked just fine yesterday on real 3 phase at the shop I bought it from so I know that's good.

I must be missing something in the setup, hoping someone has used this particular drive...

Thanks

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[Powermac]

Find your VFD's manual and follow the instructions for running it with single phase in and 3 phase out.
The motor voltage should be set to the appropriate 230-40 volts, not 170.
Turning it down to 170 and getting 236 in output makes no sense at all.
If it is new from factory,it needs to be set up to convert from single to three phase normally, and the relation between single and three phase is,square root of 3, why 170 volts makes no sense.
But if it is set up for a standard frequency of 50 Hz instead of 60 that i assume you have, this might very likely be the cause for the voltage error.

IS the VFD of the correct size?
I just took the liberty to copy -paste here:
For single-phase input, it is important to take a few more things into consideration. If the load is 3 HP (roughly a 230 VAC motor with an FLA below 10 amps) or below it is likely that we have a drive built for single phase input in stock for you to hook up and run with. If your needs are greater than 3 HP, then it is possible to use a drive built for three phase input, however the drive must be properly sized for your application. This is because the diode bridge is meant to carry current through all three legs. Thus, the rule of thumb for sizing the single phase input on a three-phase drive is to use a VFD rated for 2 times the FLA of the motor. For example if your motor is a 10 HP motor with a FLA of 28 amps, then you would need to select a VFD with an amp rating of 56 amps which ends up being around 20 HP.

Never touched a Mitsubishi VFD though only Omron/Hitachi and ABB,so i'm no expert.
Troubleshooting them 99% of the time solved in the configurations, and chances are a call to tech support will solve it quite fast.
Else start at the top of the manual and work your way through every point in the instruction manual, for programming and parameters.

I would disconnect the lathe, and measure output values between all 3 phases, if you don't know what your doing, your lathe can get hurt.

Is your coolant pump also 3 phase? if it is and does run, check the relation between the phases in how much ampere's it uses.

Is the VFD set for the correct frequency? 60Hz i assume as your in the US.
According to the online manual the base frequency is normally set to 50 Hz.

Have you checked the direction of rotation?
Something that won't give you issues in a single phase setup.

Have you set the parameters correctly for how much current it needs to deliver ? (Ampere)

Have you set it to convert from single to three phase?

IS the parameters for cutoff in power supply set correctly?
And is the VFD big enough so it does'nt cut off on the thermal OL relay during startup?
Remember a 3 phase engine pull 6-7 times the current during startup for a few seconds, if it's started directly.

Have you checked you have the correct voltage delivered at all 3 phases on your motor?


Do you get any alarms/reports on the VFD or Lathe when it stops the spindle?

 

[cal50]

You need a list of the parameters of the vfd to check the settings. I am running a Mitsubishi on my Logan 3 phase lathe but I am using a drum switch for on / off & reverse. It's likely just a parameter setting.

 

[Turd in the Pool]

Please be aware that I barely know anything about electricity other than it shocks you.

This is just a shot in the dark but something you might check. There is a switch on the access door that keeps it from running if it is open. Make sure the door is closed and the switch is not faulty.

 

[jonaddis84]

Well got it running today. My retarded assumption that I could just plug the thing in and have 3 phase power going to the lathe and it would work just as if it had true 3 phase service was way wrong.

Ended up wiring all the lathe controls into the vfd now it works like a charm. The wiring is actually much simpler with a vfd than it was on the lathe to begin with.

Maybe someone knows this...I wired the foot brake into the safety stop circuit of the vfd, and it does shut down the vfd with dc braking, but as soon as I let off the pedal it turns back on. Haven't been able to locate a parameter to adjust that.

Looks like I need to get a braking resistor, it works fine at 800 and lower rpm, but over that the drive errors out and spindle coasts to a stop.

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[Powermac]

Well if you have wired the foot pedal into the safety stop circuit it kind of says itself why it happens.
If you think of your foot pedal as a light switch, every time you push it down it turns the light off, and every time you release your foot you turn it back on.
As it sounds you basically use the emergency stop via your foot brake, most likely no perimeter in the VFD that will fix that, if it's connected directly into the cicuit.
A impulse relay would, but it would then start only when you pressed the pedal again, and i'm quite sure that's not what you are looking for.

I assume you really just want to have a foot pedal brake?
Depending on the VFD it can be possible to wire the foot brake, to the DC brake controls directly, that would get rid of your problems.

Not much of a wonder that the drive errors out if you brake the lathe via your VFD's emergency stop really.

 

[jonaddis84]

Well if you have wired the foot pedal into the safety stop circuit it kind of says itself why it happens.
If you think of your foot pedal as a light switch, every time you push it down it turns the light off, and every time you release your foot you turn it back on.
As it sounds you basically use the emergency stop via your foot brake, most likely no perimeter in the VFD that will fix that, if it's connected directly into the cicuit.
A impulse relay would, but it would then start only when you pressed the pedal again, and i'm quite sure that's not what you are looking for.

To me a safety stop circuit would shut the drive down, and not turn immediately back down until you reset it. I may be able to use something that was originally wired in the lathe to make it work. Obviously there had to be some relay that, when the foot brake was actuated, would open and not re-close until you put the forward/reverse lever back in the off position. Im not sure how that would have worked though because the foot brake switch is normally closed and opens when depressed.

I assume you really just want to have a foot pedal brake?
Depending on the VFD it can be possible to wire the foot brake, to the DC brake controls directly, that would get rid of your problems.

I want to have the ability to tap the footbrake for emergency shutdown purposes, or for metric threading to stop it immediately, and I want the drive to power down and not power back up until something resets it whether that be pressing the reset button on the VFD or putting the forward/reverse switch back into neutral.

Not much of a wonder that the drive errors out if you brake the lathe via your VFD's emergency stop really.

Like I said, the drive DC brakes fine under certain RPM, but there is no built in resistor for higher loads. I ordered one last night. The logic for returning the forward/reverse switch to neutral, and for the safety stop circuit are exactly the same, uses the same deceleration parameter. That is what doesnt make sense to me, a safety stop should have a separate parameter to allow you to decide what happens. Perhaps some models do have that, Ill make it work some other way.

 

[Powermac]

To me a safety stop circuit would shut the drive down, and not turn immediately back down until you reset it. I may be able to use something that was originally wired in the lathe to make it work. Obviously there had to be some relay that, when the foot brake was actuated, would open and not re-close until you put the forward/reverse lever back in the off position. Im not sure how that would have worked though because the foot brake switch is normally closed and opens when depressed.

Yes a safety stop should shut the drive down, and stay that way until you reset it, if not it's not a emergency stop.
Yes i know how the footbrake works, just like any NC (Normally Closed) switch, like an emergency stop or a normal stop switch. A impulse relay can do this if wired right, a programmable relay or a small easy programmable PLC would do it even better.
Relays have a tendency to wear out while a PLC has no moving internals so they are a lot more trustworthy and you have a lot more options for making functions, and most have several I/O ports, so it can multitask.

I want to have the ability to tap the footbrake for emergency shutdown purposes, or for metric threading to stop it immediately, and I want the drive to power down and not power back up until something resets it whether that be pressing the reset button on the VFD or putting the forward/reverse switch back into neutral.

Yes this is where a programmable relay or a small lightweigt PLC shines, the PLC is easier to use and you can choose whatever input you want to reset the emergency stop function, the new lightweight models, usually has a display with easy programming that you can do without a computer.
A PLC is the most reliable option, it's still electronic though, but even a mechanical emergency stop can wear out, or a connection work loose, have seen it before.


Like I said, the drive DC brakes fine under certain RPM, but there is no built in resistor for higher loads. I ordered one last night. The logic for returning the forward/reverse switch to neutral, and for the safety stop circuit are exactly the same, uses the same deceleration parameter. That is what doesnt make sense to me, a safety stop should have a separate parameter to allow you to decide what happens. Perhaps some models do have that, Ill make it work some other way.

Your absolutely right, the safety stop should have a separate parameter all together. Your not supposed to be able to program them so you can decide what happens though, just from simple safety reasons, and the MFG i assume want to be free of any liability.
And yes the VFD's i have any experience with has separate parameters for both, but they are not exactly economic models.