Anybody using Invertek 20-240V input 1Phase drives? - Looking for P-07 info

Hi everybody,

I'm looking at an Invertek 200-240V single phase input drive. [ODE-3-220105-1F42]

I'm to figure out if it will take a P-07 Value less than 200 Volts to match the weirdo 115 3-Phase motor on my Super 11 lathe. This is the one i was talking about in another thread here.


The drive manual's P-07 setting says "For Induction Motors, this parameter should be set to the rated (nameplate) voltage of the motor (Volts)."

Can somebody help me verify that the drive will accept lower values than 200V? Specifically, can you try setting it to somewhere less than 120V and see if it takes it?

I was going to let the voltage overrun and just limit the current but in testing, I've found it really doesn't like voltage in excess of the name plate (115V). More on that later.

Also, what P-51 Motor Control mode do you run yours in when using a lathe? I'm confused by the various control modes [i.e. Vector speed control, V/f, PM motor vector speed control, Synchronous Reluctance and LSPM motor vector speed control]. I was looking for a description but can't find it on the Invertek site or in the manual. (not obvious for a noob :-).

Thanks a lot,

-Dave

You can check with the company tech. to ask if will operate as you want it to be, the manual states that the P-07 minimum is 0 volts and maximum of 250V. So it should operate as you want set to 115-120V. Set the other motor parameters P-8, 9, 10. On P-51 I would start out with 1: V/f mode first which will not use VFD feedback to adjust the motor function. If the motor operates correctly and does not get too hot, then switch to 0: Vector speed control mode which will give better motor control and low speed operation.

mksj said:

You can check with the company tech. to ask if will operate as you want it to be, the manual states that the P-07 minimum is 0 volts and maximum of 250V. So it should operate as you want set to 115-120V. Set the other motor parameters P-8, 9, 10. On P-51 I would start out with 1: V/f mode first which will not use VFD feedback to adjust the motor function. If the motor operates correctly and does not get too hot, then switch to 0: Vector speed control mode which will give better motor control and low speed operation.

Click to expand...

Thanks,
Since i posted that, I've got a response back from the company stating DC bus is not adjustable and they expressed some concern that the higher dc-bus voltage would compromise the motor insulation -- I'm not so concerned about that as the enamel insulation should be good to 4KV before breakdown. To know what the real story is, I need to scope the output PWM to know what's going on(chicken and egg situation) but from that info it seems the output is based on the power (integral of IV output to the motor).

-Dave

bigwave said:

Thanks,
Since i posted that, I've got a response back from the company stating DC bus is not adjustable and they expressed some concern that the higher dc-bus voltage would compromise the motor insulation -- I'm not so concerned about that as the enamel insulation should be good to 4KV before breakdown. To know what the real story is, I need to scope the output PWM to know what's going on(chicken and egg situation) but from that info it seems the output is based on the power (integral of IV output to the motor).
-Dave

Click to expand...

The amplitude of the pulses does not change, it always is as high as the DC bus. But the width of the pulses is adjusted to get the effective voltage lower. it is just applying "volt-seconds" to the motor, and volt-seconds are an energy measure.

Yes, the number and amplitude of the energy pulses becomes power in the motor (less losses). the other way to look at that power is volts x amperes, as long as they are measured together and multiplied on an instantaneous basis. So there you get the volts equivalent of each pulse.

Invertek is a good company, they make very capable products. I used to work for a consulting company that was associated with the US branch of Invertek (the importer).

JST said:

The amplitude of the pulses does not change, it always is as high as the DC bus. But the width of the pulses is adjusted to get the effective voltage lower. it is just applying "volt-seconds" to the motor, and volt-seconds are an energy measure.

Yes, the number and amplitude of the energy pulses becomes power in the motor (less losses). the other way to look at that power is volts x amperes, as long as they are measured together and multiplied on an instantaneous basis. So there you get the volts equivalent of each pulse.

Invertek is a good company, they make very capable products. I used to work for a consulting company that was associated with the US branch of Invertek (the importer).

Click to expand...

In my case, motor amperage is high relative to HP for my low-voltage motor. My inclination was to double the HP capacity of the VFD (3HP vs 1.5 HP) so that the output stage can source enough current - in running some motor tests unloaded (save for a flywheel, the motor seems to be happy at about 7-8 Amps - PWM output will limit VA but i'm thinking output current needs to be high enough for reasonable flux density (ampere turns). Does that sound reasonable?

Yes, you do need to have ampere capacity in the VFD sufficient to handle the required motor amperage. That implies a VFD that is 2x the power that the motor HP would suggest, or possibly more, since your motor voltage is lower than the VFD normally would provide.

If the motor is 1 HP, and the voltage is half the VFD rated, then current will be about double what a 230V motor of 1 HP would draw for full power.

JST said:

Yes, you do need to have ampere capacity in the VFD sufficient to handle the required motor amperage. That implies a VFD that is 2x the power that the motor HP would suggest, or possibly more, since your motor voltage is lower than the VFD normally would provide.

If the motor is 1 HP, and the voltage is half the VFD rated, then current will be about double what a 230V motor of 1 HP would draw for full power.

Click to expand...

Cool, thanks!

-D