VFD potentiometer help.

[toolferone]

I'm in the process of hooking up my first VFD. A Teco FM50. I tested it on the bench first the basic setup went fine without any external switches or the potentiometer yet. I hooked up the potentiometer and reset the parameters on the function key and tried it it works sort of, it won't go below 60 Hz it goes from 60 to 100. I have the VFD range set from 0 to 100 Hz. I have confirmed that I have a three wires hooked up correctly. What are you thoughts on this? It is a cheap Chinese 10k pot. My first thought is just to wire up one of the extra pots I have and see if it does the same thing.

 

[Davefr]

I'm in the process of hooking up my first VFD. A Teco FM50. I tested it on the bench first the basic setup went fine without any external switches or the potentiometer yet. I hooked up the potentiometer and reset the parameters on the function key and tried it it works sort of, it won't go below 60 Hz it goes from 60 to 100. I have the VFD range set from 0 to 100 Hz. I have confirmed that I have a three wires hooked up correctly. What are you thoughts on this? It is a cheap Chinese 10k pot. My first thought is just to wire up one of the extra pots I have and see if it does the same thing.

Set main freq. source to "pot on keyboard". Does that set the speed correctly? If not then double check your selections for both lower frequency limit and start frequency.

Other then that, try a factory reset of the VFD and try again.

Test your pot on the bench and verify you have it wired correctly and main freq. source selected as external AVI signal input.

On my Teco L510 they recommend a 1k-5k pot. (not 10k). Try a 1K pot to give it a stronger signal. Make sure it's linear taper vs audio taper. Teco also recommends you shield the control cable to the pot and ground the shield at the VFD side but I didn't bother.

Good luck,

 

[toolferone]

When I control the speed on the VFD it works correctly. I will need to look up how to test the pot and do that next. Unfortunately it's going to be several weeks before I can get back to the shop.

 

[Majordisorder]

Tom, just curious as to what motor you are running at 100 Hz. Why not try setting it to run between 0 and 60 Hz.?

 

[Techie1961]

Try a 2K pot and make sure it isn't an audio pot. Get a linear one.