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teco 1hp 230v VFD starts backwards and slow

Mr_Bill

Aluminum
Joined
Apr 22, 2007
Location
cincinnati, ohio
Hi gentlemen

I have an older Teco 1hp VFD 230 single phase to 230v three phase VFD. I had been using this VFD with a 3/4 horse motor with no problems. I upgraded to a 1 hp motor and I have a problem that I can't figure out and don't understand. When I attempt to start the motor at any frequency, it turns slowly in the wrong direction most of the time. Sometimes but rarely it will start and come up to speed in the correct or reverse direction. I have looked at all settings and can not solve the problem. Can you make any recommendations please so it will start in the correct direction as it used to when connected to the 3/4 hp motor? Both of the motors are GE 3 phase motors and are wired correctly. I have tried re-arranging all three phase lines with no change in the outcome. The only item I changed was the motor. When it does start up and run at the correct speed it performs properly, a variable speed, sufficient power no weird noises and no smoke escaping.

Here is what the unit is

[h=1]1 HP, 230 Volts, 1 Phase, IP 20, Teco, JNEV-201-H1 MODEL #: JNEV-201-H1 [/h]
230 Volts 1 Phase Input, 230 Volts 3 Phase Output

Bill
 
Last edited:
Bill:

If you swap any 2 of the phases at the output of the VFD(or at the motor) the direction should be reversed.
 
There is a programing parameter in the VFD for motor size, is this set to 1HP?
Running slow, are you sure the motor is not wired for 440VAC operation?
 
Post the nameplate tag of the motor.

Is the motor starting unloaded?

What is the motor's load?

SAF Ω
 
Starting poorly suggests that one phase wire is not reliably connected, or the motor has an issue, or the VFD has an issue...

A 3 phase motor should start easily and in the same direction every time. If it does not, it is either not getting 3 phase, one of its wires is not connected, or it has an internal problem.

Many 1 HP motors have a thermal protector. Those things are not immortal, they can go bad. Could be the case. An ohmmeter check should give an answer to that question.

My very first check would be to try that VFD with another motor. If it runs the other motor OK, then the one you are now trying to use is suspect.
 
Starting poorly suggests that one phase wire is not reliably connected, or the motor has an issue, or the VFD has an issue...

A 3 phase motor should start easily and in the same direction every time. If it does not, it is either not getting 3 phase, one of its wires is not connected, or it has an internal problem.

Many 1 HP motors have a thermal protector. Those things are not immortal, they can go bad. Could be the case. An ohmmeter check should give an answer to that question.

My very first check would be to try that VFD with another motor. If it runs the other motor OK, then the one you are now trying to use is suspect.
Most failures inside of the VFD that might cause this would be showing up as a fault code. I like the idea of a bad connection or a thermal protector in the motor that is not working right. That would explain why it sometimes runs correctly. When you get a partial connection on one phase inside of the motor, it can spin in somewhat random directions.
 
Hook the drive back up to the old motor. If it runs that motor fine, it's the motor or wiring.

Re: Autotuning: normally I would agree with that approach, but that particular Teco drive is basically a V/Hz drive with an automatic voltage boost at low speeds, it's not really a Sensorless Vector Drive (even though they say so). There is no tuning parameter for it, which is how you can tell...
 
That sounds exactly like a three phase motor trying to start on single phase or with a very weak third leg.

Disconnect one leg and briefly run the motor (be sure to isolate that wire, it will still develop a nasty voltage). Do that with each leg. I suspect once you will see no change in behavior and twice you will see no motor movement at all, or very, very little.

If the above is true, wire the VFD back to the old motor. If the old motor works fine, then the VFD is fine and your other motor is wired wrong or burnt out.
 
Or the drive cannot handle a 1 hp motor. Even though the manual or drive name plate says 1Hp. Doesn't make it so on a ChiComm product.
 
I wanted to thank everyone for their input. This caused me to take another look at all the possible settings in the VFD. I didn't think that it would be that different with the 1/4 hp increase but evidently, it did. I updated the settings from F43 to F50 and that has solved the problem. It now starts good and runs great. It even starts at slow, mid and high RPMs forward and reverse. There were some good suggestions and ideas that I hadn't thought about. Again Thanks
 








 
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