[Ben Colby]

I have a TECO FM100 2 horsepower, 7.5 amp, ac inverter powering my Supermax handmill.
Single phase power into the inverter, three phase power to my mills motor.
It's a 2 horse power, 3 phase, 5.6 amp, 1720 rpm, Taiwanese motor on a step pulley head.
My problem is the inverter alarms out frequently and must be reset. The most prevalent alarms are OC-D , and OC-C.

OC-D = Overcurrent during decel
OC-C = Overcurrent during constant speed

For the OC-D I have extended the decel time from 10. (defualt setting) to
40. without much luck. For the OC-C the manual says to check the load condition and or install a reactor between the power supply and the inverter.
I'm a machinist not a electronics guy, so I'm not sure what load condition or
what's a reactor?

All I know is, it runs great, changes RPM ranges well, has never stalled or
alarmed when running, but after the motor has been stopped and I go to
start it up again I get an alarm. Probably alarms once out of every dozen
times, sometimes more sometimes less.
Any advise will be greatly appreciated.
Thanks,
Ben

[Bubba]

Ben,
I have a FM-100 on a 2HP motor and have had none of what you are experiencing.
Just a wild guess, but when you hooked up the single phase 220 to it, did you hook to L1 and L2? Seems I remember seeing that caution in the instructions.

Also, have you used large enough wire both for the single phase and 3 phase?

As stated, these are just wild guesses.

[Al_The_Man]

Maybe the characteristics of your particular motor, A reactor is a three phase choke placed between the VFD and the Motor.
Many transformer manuf. will supply them, I used to get from Hammond.
Does the VFD have auto tuning? If so that may help.
Al.

[Ben Colby]

I know the wiring size is sufficient because it's the same gage as used on my
5hp geared head lathe and two 5hp CNC millings machines. I'll pull my main panels cover and trace L1 and L2 to make sure they are correct.
I've been told taiwanese motors pull more power than USA made models?
It alarmed out 14 times yesterday during a 6 hour shift. It's just getting to be
a major pain on whomever is operating it.
I'll look for a reactor and see what I can find. The VFD doesn't have auto tuning as far as I can tell, but it does have V/HZ pattern settting. There are
18 different V/F patterns but I have no idea how to approach this other than trial and error.

Thanks
Ben

[in2steam]

I have a TECO FM100 2 horsepower, 7.5 amp, ac inverter powering my Supermax handmill.
Single phase power into the inverter, three phase power to my mills motor.
It's a 2 horse power, 3 phase, 5.6 amp, 1720 rpm, Taiwanese motor on a step pulley head.
My problem is the inverter alarms out frequently and must be reset. The most prevalent alarms are OC-D , and OC-C.

OC-D = Overcurrent during decel
OC-C = Overcurrent during constant speed

For the OC-D I have extended the decel time from 10. (defualt setting) to
40. without much luck. For the OC-C the manual says to check the load condition and or install a reactor between the power supply and the inverter.
I'm a machinist not a electronics guy, so I'm not sure what load condition or
what's a reactor?

All I know is, it runs great, changes RPM ranges well, has never stalled or
alarmed when running, but after the motor has been stopped and I go to
start it up again I get an alarm. Probably alarms once out of every dozen
times, sometimes more sometimes less.
Any advise will be greatly appreciated.
Thanks,
Ben

I did a retro fit on a similiar size motors(8) about 2 years ago, they needed to be re-insulated, or basicaly sent out and rebuilt. They would start doing overcurrent on decell and constant running after they got warm. The inverter broke down the insulation as it was not designed to be run with it after a few months of reseting the drives I started to get failures in the drives. I sent the motors out and had H insulation put on which is the best you can get no more problems since. It might just be easier to get a inverter rated motor to replace the current one.

Load condition just means how hard you are working the motor, if the drive has a Amp output for the readout you might be able to monitor it to make sure you don't go over current(amps).

Chris

[Ben Colby]

Any idea where might purchase a "Inverter rate motor" ?

[in2steam]

Any idea where might purchase a "Inverter rate motor" ?

Ebay used, for new internet, or in my area you really have to go to a supplier or rebuilder for brand new. I used to work for Leeson, there inverter rated motors were called IRIS back in the day they were going to just use that for insulation and change the color of the motor to balck or green but I left before that point, other wise Baldor, marathon, emerson, and ge all had lines for sure. I would say most motors made today should have that insulation applied, the problem is that a VFD creates whats called a corona around the coils of the motor, older insulation could not handle this and it would break down. The code you are looking for on the nameplate is "H" insulation class(insul class or INS), the higher along the letter the higher the temp it can handle. Most cheap motors have "b" Leeson liked b and h, the motors I had redipped were "b" and now are "H". If you are happy with your preformace try and match the nameplate as close as possible, esp the nema class.


If I were to buy a new motor today it would be baldor, or SEW, ABB for quality.
chris

[JRaef]

A couple of things you can try first.

First, check the nameplate of the motor to make sure it is really designed for use on the voltage you have available. If not, you need to adjust the VFD output to match whatever the motor nameplate says. For example, the motor may have been designed for 220V 50Hz, then they may say you can run it at 240V 60Hz. But ideally the V/Hz ratio needs to be the same. 220/50 = 4.4V/Hz, but 240/60 = 4 V/Hz. So already, the V/Hz pattern is not optimal and you are slightly under fluxing the motor, but that's usually OK, you just lose a little torque. But if your line voltage is only 230V as most US households are, then 230/60 = only 3.83V/Hz so now you are seriously under fluxing the motor which means you are NOT getting the full amount of torque out of it, and you can overload it even though the current is not unusually high. The end result is that you get OC-C faults.

Next, if that doesn't help, find the "Carrier Frequency" setting function in the drive and set it to the lowest setting. This will make the motor become noisy (as in a whining noise), but is best for the motor, especially older ones or those not designed for inverter use.

Get a reactor only if the other two things don't help. A VFD is not really putting out AC power, it is putting out DC pulses at high speed and alternating direction, which "tricks" the motor into thinking it is seeing AC. Those pulses are what is behind the carrier frequency mentioned above, The higher the pulse rate, the less noise the motor makes, but the harder it is on the insulation of the motor windings. Some cheap motors cannot take it and the insulation begins to break down. "Inverter Duty" motor just have higher voltage ratings on their insulation so that the effects of the pulses is lessened. A reactor in between the VFD and the motor will slow down the rise time of those pulses to where the motor can handle it better.

The OC-D faults are just because your load is regenerating as you try to stop. If you are trying to brake the motor without a Braking Resistor, don't do it. That drive does not do well with that task. Either set it for "Coast to stop" or buy a braking resistor for it, the OC-D faults will go away.