How to reverse an AB Stepper Motor? Need help

[byassin]

Hello everyone,

I have a AB Stepper Motor connected to an AB Ultra series 200 drive. The drive is connected to an AB Micrologix 1500 PLC.

The drive is setup in Analog mode. The PLC is sending a drive enable signal, drive reset signal (Thru a connected Isolated relay module) and the speed reference (thru an Analog Output module).

We just recently replaced the motors connected with these drives and we need to reverse the motor rotations.

Should i be looking at the drive to reverse the rotation? or is there something that can be done in the PLC ladder program to reverse?

Please help! Thank you!

 

[keithkyll]

Can you change wiring at the motor? Swap A and B phases. To make this clear, mark motor wires 1-4. New wiring is 3,4,1,2

 

[Ken Roach]

If the motor is connected to an Ultra 200 controller, it's definitely an AC Servomotor, rather than a Stepper motor.

Ordinary three-phase AC motor rotation can be reversed simply by swapping two of the motor phase leads. Try switching the wires on two (only two !) of the "R, S, T" motor terminals.

 

[byassin]

Thank you for the quick reply. let me make sure i am understanding you correctly... and excuse me in advance if i ask a stupid question as i am not familiar with motors... Your talking about the power cables and not the motor encoder cable. correct?

The motor power cable right now which is connected to the drive. there are 4 wires:

R1: Brown Cable - Which is R phase according to Drive manual
S1: Black Cable - Which is S Phase according to Drive manual
T1: Blue Cable - Which is T Phase according to Drive manual
Ground: Green Ground cable.

So what should I be swapping? based on the above cable combination R1 with S1?

 

[byassin]

If the motor is connected to an Ultra 200 controller, it's definitely an AC Servomotor, rather than a Stepper motor.

Ordinary three-phase AC motor rotation can be reversed simply by swapping two of the motor phase leads. Try switching the wires on two (only two !) of the "R, S, T" motor terminals.

Thank you Ken. so I can switch R with S or R with T or S with T as long I switch only two... and that will do the trick?

 

[wolverine1981]

Yes changing phases R & T will do the trick.

Tom

 

[byassin]

Thank you All.

 

[ajay34]

Rst = clockwise rotation
str =anticlock wise rotation
trs= clockwise rotation..

Swaping any power cable will do the trick ..

 

[daba]

An interesting observation......

On most jobs I worked on, more than 50% of the 3-phase motors were going "wrong-way" and had to be reversed during commissioning.

A quick word with the design office, asked them to reverse ALL MOTOR schematics to make later commissioning jobs easier.....

Guess what... later jobs still needed more than 50% of motors to be reversed !!

Is this a manifestation of Sod's Law ?

 

[ajay34]

i agree on that but same time it depend on how the motor was installed at 1st place..basiclly i would say depend on the mechinal design or flow of the item driven by motor .

 

[byassin]

so I basically followed the recommendation and reversed the phases. Swapping R with T. and now my drive is throwing the following error:

Internal filter protecting the
motor from overheating has
tripped.
Reduce acceleration rates
Reduce duty cycle (ON/
OFF) of commanded
motion.
Increase time permitted for
motion.
User larger drive and motor.

Please help!

 

[bkottaras]

so I basically followed the recommendation and reversed the phases. Swapping R with T. and now my drive is throwing the following error:

Internal filter protecting the
motor from overheating has
tripped.
Reduce acceleration rates
Reduce duty cycle (ON/
OFF) of commanded
motion.
Increase time permitted for
motion.
User larger drive and motor.

Please help!

Pretty simple actually.
The motor is underated for the load.
Or
You are trying to get to position faster than what you are limited by what the hardware can do.
Decrease the Accel/Decel values or allow more time for the motion to complete prior to issuing another command.
If you adjust the above and still cannot make it, I'm afraid you will need a larger motor/Amp.

 

[OkiePC]

Maybe I am mistaken, but won't the Ultra servo drive complain if you simply reverse the motor power leads without also reversing the feedback signals? Isn't it preferred to leave the motor and encoder wiring alone and reverse the commanded direction?

I agree that if you are getting an IPM thermal fault that the drive has encountered too much load.

 

[bkottaras]

Maybe I am mistaken, but won't the Ultra servo drive complain if you simply reverse the motor power leads without also reversing the feedback signals? Isn't it preferred to leave the motor and encoder wiring alone and reverse the commanded direction?

I agree that if you are getting an IPM thermal fault that the drive has encountered too much load.

Paul,
I haven't touched the Ultras in a while but I was thinking within the same lines as well.
I know that you can use the "Polarity" to reverse the actual motor rotation even without having to alter your wiring or Commanded direction.
I have used it with the Kinetix setup a few times.
It is done through software RSL5K under one of the axis tabs (can't remember which one though).

 

[ajay34]

what are the current motor rated amp compare to previous motor ..and what are running or starting amp
of motor .r it sound like current running motor are overloading. .can you let us know what item the motor are driving ?