Any VFD experts to help with V/Hz challenge?

Techie1961 · Mar 3, 2016

I'm having a tough time trying to figure out the setup of a J1000 VFD that I have on my drill press. It's a pretty basic setup where I want to have a pot provide me with a range from 3Hz to 150Hz and have good torque at the lower RPMs and full power at the higher RPMs.

I've tried to use the default settings by initializing it as a 3-wire setup but I can stop the motor with my hand at very low RPMs and the vast majority of the range seems to be at the top half of the pot. I know that the voltage needs to be 220 at 60Hz and then constant at 220V above that. Not sure how to achieve this. This is a section from the manual.
No. Parameter Name Setting Range Default
E1-04 Maximum Output Frequency 40.0 to 400.0 Hz 60 Hz
E1-05 Maximum Voltage 0.0 to 255.0 V 230 V
E1-06 Base Frequency 0.0 to 400.0 Hz 60 Hz
E1-07 Middle Output Frequency 0.0 to 400.0 Hz 3.0 Hz
E1-08 Middle Output Frequency Voltage 0.0 to 255.0 V 18.4 V
E1-09 Minimum Output Frequency 0.0 to 400.0 Hz 1.5 Hz
E1-10 Minimum Output Frequency Voltage 0.0 to 255.0 V 13.8 V

Alchymist · Mar 3, 2016

Not sure, but I think you are overly optimistic in expecting such a wide range of frequency. Doubt a 60 Hz? motor is going to run very well at 3 Hz or 400 Hz. I would guess a more realistic range would be more like 30 Hz to 120 Hz or perhaps a bit higher. Hang on and some one who sets these up for a living will be along to cue things up.

Pwrgeek · Mar 3, 2016

Need motor nameplate.

Sent from my iPhone using Tapatalk

Techie1961 · Mar 3, 2016

Pwrgeek said:
Need motor nameplate.

Sent from my iPhone using Tapatalk

This is the motor that I put in. I've run it at 150Hz for a bit and it has new bearings and seems smooth. I'm not likely to run it this high, though it would be nice for the occasional really small drill bit. I also want to run it as a 1HP and not it's full HP as I don't need it and the VFD isn't big enough. The plate says HP 1.3, KW 0.96, RPM 1700, Service S1, IP 54.

Techie1961 · Mar 3, 2016

Alchymist said:
Not sure, but I think you are overly optimistic in expecting such a wide range of frequency. Doubt a 60 Hz? motor is going to run very well at 3 Hz or 400 Hz. I would guess a more realistic range would be more like 30 Hz to 120 Hz or perhaps a bit higher. Hang on and some one who sets these up for a living will be along to cue things up.

Thanks Alchymist. I wasn't really sure what to expect from it and have looked around the web a fair bit. It seems that 150Hz isn't too much to ask but like you say, the 3Hz is pretty low. The minimum that is set by default when re-initialized, is 1.5Hz. I figured 3Hz was more realistic but hey, whadda I know. Not much yet. :lol:

Pwrgeek · Mar 3, 2016

Below 30Hz induction motors such as yours need a boost of voltage of about 50% (above the constant V/Hz line) to overcome stator winding resistance. This will be especially prevalent below 10Hz. If you want to operate down as low as three Hz I would try the below parameters to start and adjust them as you see the performance you want or get too much heat out of the motor at low speeds. Keep in mind that the motor you have there is Fan cooled so you don't want to run it at low speeds for long periods as it will overheat.

E1-04 Maximum Output Frequency 40.0 to 400.0 Hz 150 Hz
E1-05 Maximum Voltage 0.0 to 255.0 V 230 V
E1-06 Base Frequency 0.0 to 400.0 Hz 60 Hz
E1-07 Middle Output Frequency 0.0 to 400.0 Hz 10.0 Hz
E1-08 Middle Output Frequency Voltage 0.0 to 255.0 V 38.3 V
E1-09 Minimum Output Frequency 0.0 to 400.0 Hz 3.0 Hz
E1-10 Minimum Output Frequency Voltage 0.0 to 255.0 V 17.25 V

Pwrgeek · Mar 3, 2016

Also are you sure you have the motor wired right. You need to be using the 220V jumper configuration with these settings. If you're in the other configuration that would explain some of your low torque problems.

matt_i · Mar 3, 2016

I had no idea the motor voltage should vary to something other than nominal line voltage, no matter what the pwm value was applied.

I probably would have set all of the output voltages to 240vac and then tampered with the middle frequency value. This could result in smoke though

Pwrgeek · Mar 4, 2016

matt_i said:
I had no idea the motor voltage should vary to something other than nominal line voltage, no matter what the pwm value was applied.

I probably would have set all of the output voltages to 240vac and then tampered with the middle frequency value. This could result in smoke though

Not could ... would. At half frequency your flux density would be twice the design value. That's when things would begin to get interesting in a hurry.

Techie1961 · Mar 4, 2016

Pwrgeek said:
Below 30Hz induction motors such as yours need a boost of voltage of about 50% (above the constant V/Hz line) to overcome stator winding resistance. This will be especially prevalent below 10Hz. If you want to operate down as low as three Hz I would try the below parameters to start and adjust them as you see the performance you want or get too much heat out of the motor at low speeds. Keep in mind that the motor you have there is Fan cooled so you don't want to run it at low speeds for long periods as it will overheat.

E1-04 Maximum Output Frequency 40.0 to 400.0 Hz 150 Hz
E1-05 Maximum Voltage 0.0 to 255.0 V 230 V
E1-06 Base Frequency 0.0 to 400.0 Hz 60 Hz
E1-07 Middle Output Frequency 0.0 to 400.0 Hz 10.0 Hz
E1-08 Middle Output Frequency Voltage 0.0 to 255.0 V 38.3 V
E1-09 Minimum Output Frequency 0.0 to 400.0 Hz 3.0 Hz
E1-10 Minimum Output Frequency Voltage 0.0 to 255.0 V 17.25 V

Thanks Pwrgeek, it's really appreciated. I'll play with it again this evening and let you know how it goes. The motor is definitely wired for 220V and that is a good comment to make. I'm going to take some of your information to a thread that I started on VFD installation and conversions.

Yeah, I read up on the flux density aspect and was trying to watch that. The VFD also won't allow some settings for protection.

sanddan · Mar 4, 2016

Look for a "constant torque" setting. I think that to a point you can boost the low frequency torque but as stated above a good range for a standard 3ph motor would be 45Hz to 140Hz. This is what I use for my lathe. Cooling can be an issue when running them at too slow of a speed as they have built in cooling fans on the motor shaft. I've mostly used the low speed/hz settings for tapping as you don't need a ton of torque.

rockwithjason · Mar 4, 2016

Make sure that you are using a linear pot and not an audio taper pot. This could cause the symptoms you are describing also.

Techie1961 · Mar 5, 2016

sanddan said:
Look for a "constant torque" setting. I think that to a point you can boost the low frequency torque but as stated above a good range for a standard 3ph motor would be 45Hz to 140Hz. This is what I use for my lathe. Cooling can be an issue when running them at too slow of a speed as they have built in cooling fans on the motor shaft. I've mostly used the low speed/hz settings for tapping as you don't need a ton of torque.

I know that there is a constant torque graph with some settings but I'm still a bit confused as to why you don't just put the mid point at the actual midpoint of what you want as in around 75Hz. :dunno:

I too want it for tapping but occasionally wan to run a large hole saw which will also need torque.

I was thinking that the next time I come across a pancake fan, I might modify the end of the motor and put it in in place of the shaft driven fan and control it with the VFD relay.

rockwithjason said:
Make sure that you are using a linear pot and not an audio taper pot. This could cause the symptoms you are describing also.

Interesting and thanks for that. I didn't know about the different pots. I thought they were all linear but the one that I have is a linear pot. Thanks Jason.

Techie1961 · Mar 5, 2016

I reconfigured the VFD and it is better. It was fairly close to the settings that PwrGeek gave me but a bit different and it is an improvement. Thanks to all that replied and it is appreciated.

I did some RPM checking with a strobe light. At the fastest belt configuration, I'm getting 3810 RPM and at the second slowest belt configuration, I'm getting 1925 RPM. I couldn't read the slowest as there wasn't enough bright time versus dark time to be accurate. I'll likely leave it on the second slowest as I'll rarely need the 3810 RPM or even the 1925 for that matter.

Any VFD experts to help with V/Hz challenge?

Techie1961

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Alchymist

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Pwrgeek

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Techie1961

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matt_i

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