P77 tuning?

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1

have few Pump etc. simple use of motor with P77, some reason if Speed Setpoint is 0 (zero) motor overload occured really fast.

have we skip some commissioning step? motors has ID run done and values feeded to prarameters.

we use direct control, not MappMotion.

2

Hi,

I think the community would need some more information:

  • screenshot of P77 configuration
  • screenshot of motor data inside project
  • photo of motor type plate + delta or star connection
  • any download via AsEPL ?
3

Hi Kari,
I’ve just unpacked and plugged in the P77 inverter and carried out some tests.

To answer your question: it all depends on the control mode you have selected (0x2C00). When using vector control (with or without an encoder), commissioning is definitely required. Assuming the motor is correctly connected and the nameplate data is accurate, you need to perform autotuning:

  • When controlled via PLK, you can use the parameter at address 0x2822/0x4 to start automatic motor and controller identification (please be patient, as it takes more than a minute). You can check the status at address 0x2832. This works on my setup.
  • When using fully direct control via digital inputs (without an interface), the commissioning tool EASY Starter is intended for this. Unfortunately, I don’t have detailed information here. However, you can check this discussion: P77 not recognized by EASY starter — perhaps the community can help us further.
    Michal
4

Hi @Kari_Kivisto , is your topic solved? if not can you provide data you were asked for?

5

Still open, i have 5 P55 and all have fully commissioned, with ID run etc.

all drives work exactly same way, if Speed setpoint is 0 (zero) and Run command is activated (127)

drive generate high current and trip on few seconds, right now workaround is, activating run only when Speed Setpoint is >0

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6

I asked because @christoph.hilchenbac had asked you for additional info. Maybe now he can help?

7

Thank you.
When I enter the motor parameters into AsyncTypePlate.xls, I get roughly the same winding data.

  • Motor parameters look reasonable, but we do not see the motor type plate …
  • check motor terminal box whether star or delta connection is wired.
  • what does motor overload mean ? Is there a current alarm, temperature alaram etc. How are you aware of an overload ?
  • According to the posted data we could expect about 4 amps magnetizing current with setpoint 0. Parameter ‘0x2D88’ as monitoring data point enables you to trace the value.
  • Motor management is ‘Vector control’ which is a closed loop and requires to check speed controller settings.
  • You can try ‘Voltage/frequency’ as motor management which is simpler approach without feedback.
8

Hi Kari,
as Christoph suggests, for simple applications (e.g., HVAC), there is usually no need for vector control, even sensorless. Use simple scalar (V/f) control instead, where the V/f curve can be adjusted to match the pump characteristics.
Michal Malek

9

yes, for Pump it would be suitable, but i have same project feeding screws and that need more better control, so any case this issue need solve.

10

Hi @Kari_Kivisto ,
maybe I’m wrong but we are talking about possible tuning issue, and I don’t see any traces, in this case it’s very hard to help you.
Additional data requested by Christoph will help our investigastion.
Thanks
Ciao
Valerio

11

@Kari_Kivisto

  • even vector control is the target, V/f might give us new insights since this is a open loop.
  • 0x2D88 (current) and 0x2B0F (actual frequency) could give some hints. You could add them as ‘Monitoring data point’ and trace them during powering on with mapp Cockpit or the good old variable trace.