PLC DC motor test

I have a new project at work and I am in need of some advice. I need to cycle test a 28vdc motor. It has to ramp up to full speed and ramp down slowly for 200,000 cycles. I have an Omron Zen but I think this may be too basic for what I need. Can I do this with a PLC and a DC drive or DC motor controller? Is there a PLC that has PWM? Any ideas or suggestions would be greatly appreciated. Thanks!!

While I'm not familiar with an Omron Zen, it sounds very possible to do. Set your DC motor drive Max output voltage to 28vdc. Hook an analog output from your PLC to the DC motor drive speed pot input if capable of a 0-10vdc (or 4-20mA) input signal. Set the PLC analog output to 0-10vdc (or 4-20mA). Slowly increment the analog output channel variable until you reach the maximum value then decrement the variable value down to a point where the DC motor stops and repeat the process. AB micrologix series are quite capable of doing this with built in Analog I/O, some micrologix are also capable of PWM/PTO on the DC output models.

ravin76 said:

I need to cycle test a 28vdc motor. It has to ramp up to full speed and ramp down slowly for 200,000 cycles. I have an Omron Zen but I think this may be too basic for what I need.

Click to expand...

Some details seem to be needed for a "good" answer.
1. Horsepower or amp rating of your motors.
2. Input power for motor controller, DC battery or AC supply and what voltage?
3. Ramp time how long?
4. Do you need to "prove that the motor is performing", or will the fact that you commanded the motor controller to run 200,000 cycles be good enough?
5. If you need to prove that the motor is "performing" do you need voltage, amp, torque , and RPM data?
6. Are the motors series connected, shunt connected, stab shunt connected, compound connected or permanent magnet? Or all of the above?
7. Reversing?
8. Will you be performing more than one test at a time?

ravin76 said:

It has to ramp up to full speed and ramp down slowly for 200,000 cycles. I have an Omron Zen

Click to expand...

You would need an encoder attached to the motor
than use a Scale With Parameters or what ever the Omron
equivalent is to scale the encoder count to the analog drive output.

Derek said:

You would need an encoder attached to the motor
than use a Scale With Parameters or what ever the Omron
equivalent is to scale the encoder count to the analog drive output.

Click to expand...

OK from the start of test
STOPPED
Start at minimum speed
Ramp to full speed (?) in one single ramp or multiples - what is time frame of ramp ie slope
How long at max speed and what is percentile motor load at full speed?
Ramp down - to stop or minimum speed? If stop how long stopped before restart? If minimal speed how long before speed back up?

Dan Bentler

Hi. I apologize for the late response. I can answer most of your questions.

1. Horsepower is not known at this moment. 40 amp rating.
2. Input power for MC: 120vac
3. Ramp time? stopped to full speed (1 sec); hold at full speed (2 sec)
ramp down to stopped (5 sec); downtime (2 min); repeat.
4. I need to prove that the motor is performing as well as performance
decline data.
5. I will need voltage, amps, torque, and RPM data.
6. One motor: Novak 28vdc brushless motor with ceramic magnets; 45,000
RPM; 40 amps.
7. No reversing needed.

Thanks again for any info you could provide.

ravin76 said:

1. Horsepower is not known at this moment. 40 amp rating.
2. Input power for MC: 120vac
3. Ramp time? stopped to full speed (1 sec); hold at full speed (2 sec)
ramp down to stopped (5 sec); downtime (2 min); repeat.
4. I need to prove that the motor is performing as well as performance
decline data.
5. I will need voltage, amps, torque, and RPM data.
6. One motor: Novak 28vdc brushless motor with ceramic magnets; 45,000
RPM; 40 amps.
7. No reversing needed.

Click to expand...

Based on this response a fairly specialized motor controller is needed. Also my gut feel is the Zen would not be a suitable partner for the motor controller.

Edit: My experience with 28VDC brushless motors is nill. Maybe someone else can chime in.

ravin76 said:

Hi. I apologize for the late response. I can answer most of your questions.

1. Horsepower is not known at this moment. 40 amp rating.
2. Input power for MC: 120vac
3. Ramp time? stopped to full speed (1 sec); hold at full speed (2 sec)
ramp down to stopped (5 sec); downtime (2 min); repeat.
4. I need to prove that the motor is performing as well as performance
decline data.
5. I will need voltage, amps, torque, and RPM data.
6. One motor: Novak 28vdc brushless motor with ceramic magnets; 45,000
RPM; 40 amps.
7. No reversing needed.

Thanks again for any info you could provide.

Click to expand...

REPLY
"motor: Novak 28vdc brushless motor with ceramic magnets; 45,000 RPM; 40 amps".

Are you driving this off a 28 VDC bus (or battery?) NO you said 120 V line.
This sounds like a "brushless DC motor" which is actually 3 phase.

DICK DV can he take a 120 VAC input VFD and set output voltage to 28V? What would be suitable unit?

If -- IF --- I am correct, you are driving off a DC bus or battery then you will need a VFD (minimum vector control?) designed for a 28 VDC supply line.
Penny and Giles may be the guys to talk to for the VFD.

Another thought - if you are testing this for someone else have them supply you with motor controller and entire system to make that motor go. I think this would also apply if you are testing an inhouse product. Test the whole system not just the motor is the main idea here.

Dan Bentler