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How to test a VSD Schneider 250 kW

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SA07

Electrical
Feb 22, 2018
365
MU
Hi
We have bought a new VSD and we are testing in workshop before installing on site. We have connected the control signals as attached. We have set a min frequency of 38 Hz. We have connected a small motor 0.37 kW for testing. When we press start push button, we can hear the VSD fan running as if the VSD has started but the motor does not rotate. We have set the kW and current the lowest possible in the VSD.

When we press emergency push button, the VSD stops. Can you please tell me what may be wrong and why the motor does not rotate?

We have contacted Schneider technical dept but have not receive the right advice up to now.

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What have you set to the min frequency 38 Hz ?

Have you followed this simpel start example?


I cant se that you have connected any potentiometer.

0_exxpxe.jpg


It is difficult to help without knowing what parameters are set or not.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein
 
0.37 kW prompts the question; Is the motor a three phase motor?

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
The VSD will later drive a submersible pump whose mini speed should be 38 Hz.
The small motor is 3 phase 400 Vac
 
Should we connect a potentiometer?
I have already set the basic parameters.


IMG_20211117_074211_xyn6ia.jpg
 
If the 24 VDC, AI1 and COM is chosen as the the drives setpoint value (reference frequency input) you cant not drive the motor without it.
I do do not know which other inputs that can be used or selected for this?
If you have chosen some constant speed reference in the parameter set, that must be chosen as the main frequency set instead of the analog input.

0_ekpy0f.jpg


I am not sure what your nominal frequency is in Mauritius 50 or 60 Hz
I would suggest that you start with setting your reference frequency to that or to the motors nominal frequency to see if it will start running and then go down from there.
It is not sure the motor will be able to start or run on a to low frequency setting.


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein
 
Nominal freq in Mauritius is 50 Hz.

We have connected a 2.2 kW motor.
We have connected a potentiometer. When we vary the potentiometer, we can see the freq changes on the display.
We have connected a stop push button with NC on DI2 and set to 3-wire. But the VSD does not start when we press start push button. We removed the stop push button and set to 2 wire. We must press the start push button continuously for the VSD to start. Else it stops after a few seconds.
We have tried autotuning. The process starts, we hear the tit,tit…. sound in the motor. Then smoke came out from the motor. We stopped the autotuning.

Is it possible to do autotuning with the small motor? We can decrease the kW to 90 kW and current to 72 A minimum. We cannot go below.

Hi moa1
Thanks for the video
Do you have a similar video how to program the VSD by using external start, stop, emergency stop and a potentiometer to run the VSD and adjust the speed?








 
We must press the start push button continuously for the VSD to start. Else it stops after a few seconds.
DI.1 is not "start" it is forward or run meaning you need to have it high all the time when you want to run or run forward.
Smoke is no good..
According to the Manuel the drive is made for 250 kW to 315 kW
Meaning that it is what the drive is trying to autotun.
Even the lowest output current would be to high for such a small motor.

0_wywpwf.jpg


Honestly I don't think I have made a autotun on a standard 3 phase AC motor, normally if you have all the motor data it is enough to get it up and running to begin with.


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein
 
3-wire control settings activate inputs DI1 to stop (NC) contact, also DI2 is now a start command with a (NO) PUSH BUTTON activation. Link: . Running autotune on this test motor will provide no useful information for your much larger (motor) installation.
Testing the drive as you are. The benefit to final installation will be only confirmation of field wiring and some parameter settings, until wiring to the real deal. Good luck
 
We have connected stop to DI1 and start to DI2 and set 3 wire. It is ok now.
We have removed the motor, started the VSD, increased the speed. The VSD remains 21-28 Vac. It does not go higher.

Is there a way to test the VSD with output not connected or with a small motor? According to my colleagues they had similar problem on a Danfoss VSD. When they connect a motor it is ok.
Plz see attached the list of parameters.


 
 https://files.engineering.com/getfile.aspx?folder=ead393c8-98c1-49c7-ab8b-99dc312d4b22&file=VSD_Schneider_parameters.xlsx
What you're trying simply might not work, I have also seen VFDs not work when attempting to run an overly small motor compared to the VFD rating.
 
What type of motor was it?
You should start with checking this.

Motor control type U/F VC Quad
Macro config Generic pump control

I think macro config should be set to [Generic Fan Control] fan.



“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein
 
Have you tried with a bigger motor? Is the control on scalar or sensorless vector?
Esperantes.
 
Can we do auto tuning on a submersible pump immersed in water? This is a new motor. We cannot separate motor from pump. Also it is immersed in water.
 
You should be able to do stationary auto tuning for line to line resistance.
Esperantes
 
We tested the VSD with the borehole pump today. It is ok.
45 Hz 270 A 260 m3/hr
46 Hz 279 A 290 m3/hr

Rating of pump 220 kW 390A 350 m3hr

Thanks all for advice
 
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