My PowerFlex 525 won’t let me speed down

[LuisR2D2]

Hello everyone!
So basically I have this PF 525 that no matter what I do won’t let me speed down. It always shows 66.66 Hz and the parameters to speed reference either Ethernet/IP or drivePot won’t let me speed down, although from the studio 5000 I can see clearly that the commended speed is being shown.
What parameters should I look up? I have already put my drive in Factory Reset by pressing P053 -> 2

 

[jstolaruk]

Have you set all of the motor parameters to match the name plate on your motor (P031-P037)?

66.66hz is higher than the default max freq (P044), that's suspicious.

The default setting for Decel is 10s, have you updated that value? (P042)

 

[mylespetro]

A couple thoughts that immediately come to mind are to check that you're configured and wired for the correct analog signal type (0-10V or 4-20mA), and check your speed reference source.

 

[joseph_e2]

If you're sure it's at factory default, it shouldn't go above 60Hz. As a test, I would unplug the Ethernet cable and do the factory reset again. Lift all of the wires from the terminal block except a jumper from terminal 1 to 11. Then use the keypad to start the drive and see what happens. If it's connected to a Logix 5k PLC via Ethernet, and the PLC "owns" it, it could be re-writing parameters as soon as it powers up or periodically or at some other time that's programmed into it.

 

[doctord]

From the picture it does not look like you have a POT to control speed or an analog input to control speed wired up. Only possibly Safety Stop and Stop Start.

 

[arpus4KM]

do you see a light next to the Pot on the face of the drive indicating it's being used as the speed source?

what's the minimum frequency set to?

there is a list of basic setup parameters, I would be sure those actually got defaulted.

are you looking at a commanded frequency or the actual frequency being output? what does the commanded frequency say it's trying to reach?

 

[BachPhi]

P044 can be higher than 60.

In fact, he did not have anything to control. No pot, no analog, no Ethernet. LOL

 

[joseph_e2]

P044 can be higher than 60.

In fact, he did not have anything to control. No pot, no analog, no Ethernet. LOL

He said it was all set back to factory default and he's using the pot built into the drive's HIM, which is the default speed reference.

 

[SCADA_Joe]

Check supply power

Verify your supply voltage is correct to the drive requirements and the drive to the motor.

Disconnect the motor. Can you regulate the speed then?

 

[LuisR2D2]

Hi Ian!
Yes here is my basic configuration and it's all set to default, except from the motor parameters

 

[arpus4KM]

Hi Ian!
Yes here is my basic configuration and it's all set to default, except from the motor parameters

Why is everything set to ethernet/ip and you have no ethernet plugged in?

I would attempt to flash the firmware on the unit then start it back up without touching any of the parameters and see if it still tries to run to max hz.

Also before you do that, change the maximum frequency to 70 hz and see if the output frequency changes with it. It almost looks like an issue I had with 527s where they would run to maximum regardless of any command. after a firmware update they stopped doing it.

 

[arpus4KM]

this may not apply since it looks like you are using 277 input. so the bus voltage looks ok. but it may be constantly trying to regulate it. out of curiosity, what is the rated input/output of the drive? and what are you using for power?

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/732853/loc/en_US#__highlight

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PowerFlex AC Drives: Output Frequency increases while Command Speed is steady

Summary
PowerFlex AC Drives: Output Frequency increases while Command Speed is steady
Question
I have an AC PowerFlex drive in which the Output Frequency to the motor keeps increasing but my speed reference is not increasing, it remains the same.

What can cause the drive to do this?


Answer
One reason could be the drive’s DC Bus Voltage is high and the drive is trying to regulate/decrease the DC Bus Voltage by increasing the Output Frequency and therefore Output Voltage to the motor in an attempt to lower the DC Bus Voltage.

Look for the Parameter in your PowerFlex drive in which you can Enable / Disable Bus Regulation.

When bus regulation is disabled the DC Bus Voltage is allowed to rise and the Output Frequency will continue to follow the command speed reference. If the DC Bus voltage rises past the DC Bus Over Voltage trip level the drive will fault out on a DC Bus Over Voltage.

The condition causing the high DC Bus Voltage should be addressed to keep the life of the drive from being shortened.

A550 for the Bus regulation enable/disable