Unknown kW rating of motor
Unknown kW rating of motor
(OP)
Hi All,
I'm on site at a new installation and we have been supplied with a Siemens inverter driven motor. On the plate, it specifies it as a 22kW (40A) and it is in a 37kW frame.
The motor (for a chain conveyor) is according to the design, meant to be a 37kW motor, however we are assured by our supplier that the motor is in-fact plated incorrectly (which I have never come across) and is a 37kW motor rather than a 22kW, as per the plate.
Is there any way I can off-line test this motor whilst on the conveyor to verify it's kW rating?
Thanks for your help.
I'm on site at a new installation and we have been supplied with a Siemens inverter driven motor. On the plate, it specifies it as a 22kW (40A) and it is in a 37kW frame.
The motor (for a chain conveyor) is according to the design, meant to be a 37kW motor, however we are assured by our supplier that the motor is in-fact plated incorrectly (which I have never come across) and is a 37kW motor rather than a 22kW, as per the plate.
Is there any way I can off-line test this motor whilst on the conveyor to verify it's kW rating?
Thanks for your help.





RE: Unknown kW rating of motor
It is very likely as the ratio between 37 and 22 is close to 1.7, which is a good approximation for sqrt(3).
If that is the case, there is nothing to worry about. You may need to read up on motor torque, speed and power.
Gunnar Englund
www.gke.org
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RE: Unknown kW rating of motor
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RE: Unknown kW rating of motor
Are you talking about 2 pole speed, 22Kw in 2 pole should be in frame 180M, 37kw 2 pole should be in frame 200L. If you are talking about 4 pole then the difference is 2 frame sizes (22Kw 4pl 180 frame, 37kw 4pl 225 frame as 30Kw is in frame 200)
I have never seen SIEMENS putting on a wrong nameplate but there is a first time for everything
Feg
RE: Unknown kW rating of motor
RE: Unknown kW rating of motor
RE: Unknown kW rating of motor
It's worth checking especially as the motor is running on inverter power.
RE: Unknown kW rating of motor
Unless the OP is running at 690Vac then I would guess the 87Hz function of using the delta (or Star) winding in the higher voltage may not be the case with this one at this power rating. The 87Hz is typically used on sub 7.5kW applications that have 240/400V Delta/Star configuration where the VFD will output 400V into the Delta winding configuration.
Most Siemens motors are 240/400 Delta/Star to about 7.5kW and 400/690 Star/Delta above.
Kentokyo
Check your Siemens nameplate and look at the part number and see if the last digit has a "-Z". If it has, then this means there is something special about the motor from the factory. The serial number will inform the factory what the 'special' is.
RE: Unknown kW rating of motor
The magical "Z" has fooled me more than once.
Met a friend of yours today, at SBT.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Unknown kW rating of motor
Do I still have friends in SBT?
RE: Unknown kW rating of motor
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Unknown kW rating of motor
I hope they didn't mention Congleton with regard to their problems - we're having a bad enough time as it is at the moment
Ozmosis - I'm afraid I have to disagree with your comment re. motor voltages. The 230/400 configuration is shown as standard up to 45kW in the motor catalogue.
One idea, is the motor in the OP a 6 pole motor for example? It might explain the size difference...
Regards,
Mort
RE: Unknown kW rating of motor
I don't think gunnar was undermining Congleton-he knows I used to work out of there, that's all.
RE: Unknown kW rating of motor
Looking at the 1LA7 motor guide - 22kW 4 pole is rated at 41.5A at 400V/50Hz, frame size is 180L.
6 pole 22kW is 200L frame size, but rated current is 45.5A.
Could kentokyo give us the MLFB of the plate, that would shed some light on it? I don't see him mention 240V in the OP?
Cheers,
Mort