Hey y’all, I am building a jer Schmitt 2/72 the entire build and power supply is built but when I went to test it the motor barely runs. It is moving but not fast and with so little torque you can stop it with light pressure. It was bought used from Facebook market place, and I was told it works. Any way to dignose and fix it? I have attached some pictures below.

what is the source power

It is a vfd hooked up to single phase 220v power that out puts 3 phase with variable frequency.

you have the Wye and Delta thing sorted?

Not sure what a wye is but it is wired in delta formation so it is in 220 voltage configuration.

Like Steve says, double check the wiring.  If only two of three leads from the motor are connected properly, it might run like you describe.  Then, I'd check the settings on the VFD.  I have two that require quite different steps to program, but there are a lot of setting that could be wrong.  If you don't have a manual, find one online.  And if there's a "restore factory settings" option, that might be worth trying.

Sounds good I took it apart to inspect the coils and rotor and all looks good there so when I get back to my shop tonight I will check wires and retry it. 
 

for reference this is the vfd I am using it comes with a manual and I haven’t changed any settings from default.

Huanyang VFD,Single to 3 Phase,Variable Frequency Drive,4kW 5HP 220V Input AC 17A for Motor Speed Control,HY Series
 

 

 

4 hours ago, Mike BR said:

Like Steve says, double check the wiring.  If only two of three leads from the motor are connected properly, it might run like you describe.

If only 2 conducting wires are correctly connected it will allow it to run at about 60% power

So far I have followed this advice and it run fast now but dosent have enough tourque to even start the grinder. Could this be due to it being a 2 pole? It barely has enough tourque to spin up.

thank y’all for the help!

 

 

I have a VFD of the same brand, but smaller.  Mine didn't come with a gauge or external switch, but does have the two rows of terminals where you can connect various control wires.  There are also settings you can program that determine what the terminals do (to some extent).  It's possible that if you run it without hooking that ribbon cable back up correctly (if you even can run it like that) or without resetting the program, there would be trouble.

More broadly, you can program the VFD to control how fast the voltage increases with the frequency.  If that's set too low, it could cause it to run fast with no torque.  (I can look at my manual tonight and see what the voltage settings are called.)

As promised, I checked my manual.  Assuming your interface is the same as mine, the obvious settings that could cause low voltage/low torque are:

Base Frequency, PD004.  Should be 60 -- a higher setting could cause low torque.  (I never bothered to change mine from the factory setting of 50, in part due to the speeds I normally use.  But that's probably not the best choice.)

Max Voltage, PD008.  Should be 220 -- a lower setting could cause low voltage/torque (obviously).

thank y’all for the help I reset and changed all the parameters and it ended up being parameter 143, motor poles. It is running and is an absolute hog. I have attached a video of the final product below. Thank you all so much for the help.

 

 

 

That’s a good one to remember. Motor poles should only affect how the VFD converts an RPM setting to frequency. And I always set mine directly by frequency. But your VFD was probably trying to run the motor at twice the rated speed . . .