Powerflex 753 VSD alarm 64 and 169

[Onelasttry]

Hi,

New to this so please bear with me.

I have this controlling a Netzsch Progressive cavity pump at 30Hz and the pumps motor is rated at 21A and is running quite hard at 18A.

Recently we are getting VSD alarms that trip the pump out. When I look at the alarms I get 64- Drive OL and straight after 169- PWM Freq reduced.

I've seen a member mention to check parameter P413- Mark OL Factor and set that to 125%.

Can I change this parameter via the HIM or do I need to get software and connect up to it?

Should there be anything else I should try for these alarms?

Appreciate your time

 

[mylespetro]

Hi,

New to this so please bear with me.

I have this controlling a Netzsch Progressive cavity pump at 30Hz and the pumps motor is rated at 21A and is running quite hard at 18A.

Recently we are getting VSD alarms that trip the pump out. When I look at the alarms I get 64- Drive OL and straight after 169- PWM Freq reduced.

I've seen a member mention to check parameter P413- Mark OL Factor and set that to 125%.

Can I change this parameter via the HIM or do I need to get software and connect up to it?

Should there be anything else I should try for these alarms?

Appreciate your time

Not going to guarantee it, but you can usually set any parameter through the HIM.

Also just for reference, you're getting a fault, not an alarm. 64 is the fault code for Drive Overload. This is different than the Motor Overload fault (fault code 7). What is the drive rating? Possible that it could be too small for the application. Looking at fault code 169 (PWM Freq Reduced), the description says:

"The PWM Frequency has been reduced from the value set in P38
[PWM Frequency] due to excessive IGBT junction temperatures.
See also P420 [Drive OL Mode]."

P420 [Drive OL Mode] has the following options:

0 = “Disabled”
1 = “Reduce CLmt”
2 = “Reduce PWM”
3 = “Both PWM 1st” (Default)

So your drive is detecting that it's in an overload condition, and simultaneously reducing its Current Limit (CLmt) and PWM Frequency.

EDIT: Sorry, for some reason I assumed this was a PF525, not a 753. Looking at the fault descriptions, it can be an alarm-type fault.

 

[Onelasttry]

@mylespetro

Thank you for that info. I will have a look at that as well. Will hopefully be tomorrow but seemed to be dragged onto more critical jobs at the moment. Will post my findings once I've had a look.

Thanks you for such a quick reply

 

[mylespetro]

Will hopefully be tomorrow but seemed to be dragged onto more critical jobs at the moment.

Isn’t that just always the way?

Not sure anything I said was super helpful, but it is useful to know that your drive is experiencing an overload on itself, not the motor. Has anyone watched the amps on the drive display as the fault occurred? Not sure what the rating on the drive is, I notice you said the pump motor is rated for 21A (415VAC?) but it’s pretty common to size the drive one size up from the application. If the drive is sized to match the motor exactly it’s possible that a momentary high current draw could trigger the Drive Overload fault.

 

[alan_505]

Last time I had a drive over current fault it was on a 1336 and one leg of the output contactor had a broken spring and was open circuit when energised, replaced spring and all OK.

 

[Onelasttry]

Hi,

I checked the drive settings and P420 Drive OL was set to both. One thing management on site didn't tell me is that the pump has had another 200m of lay flat hose added to it. We have this pump sending digestate over to a lagoon but the lagoon membrane is being repaired. So the drive is struggling because its got more work to do. I'm told it will only be another week. Let's hope it holds out. Its a sickening feeling as we don't carry spares and from what I remember the VSD is rated at 20A max which means it's underrated for that pump.

Thank you for your time. I'm going to let the VSD faults keep clogging up the alarm page on our SCADA to remind all the engineers to keep an eye in it.

 

[ASF]

One thing management on site didn't tell me is that the pump has had another 200m of lay flat hose added to it.

Ah, of course that wasn't important information to give you at the time

I'm going to let the VSD faults keep clogging up the alarm page on our SCADA to remind all the engineers to keep an eye in it.

You have made a good choice here.