Another question... What are you measuring the VFD output with? or are you looking at its display for output voltage?
A run of the mill multi-meter can't deal with a VFD output.
And another... did you measure the actual shaft speed of the motor? At "50 Hz", is it running nameplate speed? You might be going into a current limit situation on the drive, reducing the actual output.
Yes. of course. Otherwise pressure would n't have been developed.
Both multimeter and display is showing 360V.
"If VFD output is pure sinusoidal/or close to u can measure its voltage by Multimeter"
I didnot check the shaft speed; Drive is showing 50Hz, Definitely 50Hz Power is going to motor. Now motor is supposed to rotate at its speed at 50Hz whatever maybe its voltage. If it runs at 50Hz,then why the hell i am not getting desired pressure!!!!!
Probably a dumb question, but is the motor still rotating the correct direction?
the drive is probaly just showing the command for freq as most do. What is the current saying
Depending on what type of blower, wrong rotation will still produce suction or pressure but not as well. I use centrifical blowers that do it.
Also you have been asked other questions, some answers to them would help, not just come back with the above quote. The experts here spent their time to answer them.
Sorry for my quote if it is too offending.
Mine also Centrifugal blower. But pressure is not that less that i could come to a decision that it is rotating in reverse direction. And also i had to change the phase during commissioning as at first it started rotating reverse.
Here to mention, I am experiencing same for 2 systems.
Help needed!!!!
Of course it is.
You can scream for help, but until you help us, it's futile.....
You've been asked, but not provided:
What is the FLA rating on the motor
What is the Current Limit setting in the drive
What is the accel rate of the drive set to
What was the type and size of the previous OL protection you used on the fixed starter? This could give us some clue as to what kind of current was being allowed.
When someone asks you what the current is, don't respond 34-36a. That's too ambiguous. Is that what the drive is reporting? A standard 415V 18KW motor has an FLA of 36a. If you're pulling 36a then you are in current limit potentially depending on the drive set up.
Unless you're measuring rotational speed with a hand held tach at the motor shaft/fan, how do you know it's running 50HZ? Don't rely on what a dumb drive is telling you....measure it! You say the drive says 50Hz, but that is commanded frequency....what about speed feedback...what does the drive say?
1.) what the distance between motor and VFD?
2.) damper broken?
Sorry for my quote if it is too offending.
Mine also Centrifugal blower. But pressure is not that less that i could come to a decision that it is rotating in reverse direction. And also i had to change the phase during commissioning as at first it started rotating reverse.
Here to mention, I am experiencing same for 2 systems.
Help needed!!!!
Current limit overides the speed command. To maintain the proper current the drive will reduce the voltage AND the frequancy. .FLA = 36A
Overload Trip Level FU1-67 =120%
Acceleration Time = 20s
Previously used = Thermal Overload set at 22A( as star delta config.)
Soon i will let you know shaft rpm. Currently out of site.
Should i try increasing frequency? But i think that will increase the current.
Also could you please tell me how current limiting decrease the output frequency?
Thanks