VFD problems.

E

evlwhtguy

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Recently purchased a Full size sharp milling machine out of state auction in South Carolina. The machine is in beautiful condition and everything seems to be well with it but of course it is three phase. I purchased an inverter off of Amazon

Variable Frequency Drive, 5.5HP 220V Single-Phase Variable Frequency Drive VFD Speed Controller for 3-Phase 4kW AC Motor 0 - 400Hz

Amazon.com : Variable Frequency Drive, 5.5HP 220V Single-Phase Variable Frequency Drive VFD Speed Controller for 3-Phase 4kW AC Motor 0 - 400Hz : Tools & Home Improvement

It is nicely oversized for the motor since the motor on the milling machine is only three horsepower so there should be no problems with it. I programmed it to work on 60 cycles and wired it all up and plugged it into 220 Volt single phase and turned the machine on and everything seemed to be fine. When I went to turn it on the second time it didn't work and it gave me error 1, “short circuit current/overload power module protection” I got it to turn the machine on about three or four more times, but I keep getting this error.

I googled this error on the Internet and it suggests that you program the ramp up time to two or three seconds but this is not a parameter which can be adjusted in the instructions. Hoping that perhaps the inverter was a bad one I returned it and got another one and it is exactly the same. This one managed to turn the machine on one time only. And it hasn't worked since.

Does anybody have any suggestions for me. I can tap off 110 Volt current from it just fine to run the fans on the machine and the DRO and an electric drill, but every time I turn the machine on with the 3-phase current, it throws this error. I have the output of the DRO wired into to the normal on/reverse switch on the milling machine and I press the run button on the inverter and when it gets all the way up to 60 Hertz, I flip the switch on the machine to turn it on. Three or four times it has worked [Motor sounds very nice when it runs] but the rest of the time I just get the error. I have also tried turning the switch on and then pressing the run button on the VFD and it just immediately goes to error. I have checked the windings in the motor, and they are all good and have the correct number of ohms and there's no grounding in the machine I checked the switch it works correctly, and it is not going to ground except where it's supposed to.
 
+1 on what OTmachine said. The VFD must be wired directly to the motor and only the one motor. No switches, lights, transformers, any other motors or anything else can be on the output side of the VFD. If you want to use the machines controls you must wire them to the VFD's aux control inputs. If you want to power anything else you need to pull that power before the VFD or better, use a separate circuit.
How did you wire your machine, can you elaborate?
 
+2 on above posts

The 3 phase output of the VFD goes directly to the one and only 3 phase motor. Nothing else (no switches, no lamps, no controls, no secondary motors, etc.) between the VFD and 3ph motor!
 
Agree with the above posts
In addition, I have never seen a VFD that the acceleration / deceleration time was not programmable.
 
They are not a plug and play power source, if you want to go that route they need to be oversized by a factor of 4-5X times the motor/machine rated amps, and you also have the issue of the sub-systems such as transformer/breakers/etc. are not designed to operate off of PWM sign waves. If you want a plug and play option then use a Phase Perfect or RPC, and with the latter make sure the wild leg is not used for any control circuits.
 
OTmachine said:
VFD has to be wired directly to the motor using the start stop functions on the VFD.
Click to expand...
Really appreciate the prompt and definite posts from everyone. I am encouraged by the similarity in the answers from so many different people. I will update after I have re-wired.
 
Eddyde said:
+1 on what OTmachine said. The VFD must be wired directly to the motor and only the one motor. No switches, lights, transformers, any other motors or anything else can be on the output side of the VFD. If you want to use the machines controls you must wire them to the VFD's aux control inputs. If you want to power anything else you need to pull that power before the VFD or better, use a separate circuit.
How did you wire your machine, can you elaborate?
Click to expand...
Really appreciate the prompt and definite posts from everyone. I am encouraged by the similarity in the answers from so many different people. I will update after I have re-wired.
 
mksj said:
They are not a plug and play power source, if you want to go that route they need to be oversized by a factor of 4-5X times the motor/machine rated amps, and you also have the issue of the sub-systems such as transformer/breakers/etc. are not designed to operate off of PWM sign waves. If you want a plug and play option then use a Phase Perfect or RPC, and with the latter make sure the wild leg is not used for any control circuits.
Click to expand...
Really appreciate the prompt and definite posts from everyone. I am encouraged by the similarity in the answers from so many different people. I will update after I have re-wired.
 
den-den said:
Agree with the above posts
In addition, I have never seen a VFD that the acceleration / deceleration time was not programmable.
Click to expand...
The Instructions give a means of adjusting the Braking time but not the acceleration time. They do have a "Main Rising Velocity" Adjustment and also 1 through 7th Rising velocity settings, Thery are all set at 25HZ. Maybe it is called something else....also no adjustment is given in seconds except braking time and overload protection buffer time. There is an "input stabilization time" which is defaulted at 60 mS. [Is that milliseconds???] The available range is 0--------65535.

If re-wiring to use the VFD to do the on off doesn't work, I can scan the instructions and perhaps post them....but given the unanimity of the responses.....I will do the re-wiring first. Really appreciate your and everyone's help.
 
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