Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: thefox on November 20, 2014, 03:49:22 PM
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hello
:)
i have a question and i can't find the answer for it
i have a LS(LG) VFD Korean one it's 1.5KW 2HP
AND the spindle unfortunately 2.2KW 3HP so all i am asking can i run the spindle according to the VFD max output i mean could i use the VFD to run the spindle with the specs of the 1.5KW spindle coz i don't not neeed all the 3 horse power inust want to rin the spindle like it's 1.5 KW ones?
is it possible ?
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A 1.5kw VFD will run a 2.2kw motor although the motor won't develop full torque and HP if needed.
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yeah i know :) i will not get the full toque or the HP but all what i am askink can i get the HP and Torque for the 1.5KW spindle ?
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Chances are you won't need the full 1.5kw VFD output (approx 6 amps@400hz,3ph,230v) unless you are taking heavy cuts with a large cutter and high feed rates so the motor kw or HP difference between 1.5kw and 2.2kw is a moot point. The worst thing that will happen is stalling the motor. You can watch the motor amps on the VFD display. Also be aware the all cheap Chinese VFD's operates in V/F (volts to frequency) mode which means as the output frequency is reduced, i.e speed control, the output voltage is reduced which affects motor torque. High quality industrial VFD's such as Toshiba and Siemens can run in vector mode to eliminate this problem.
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thanks geh7552 :) i will buy new VFD tomorrow :) and thanks for the advice the motr did not develop full HP i got yar adivce and am just about to buy new VFD :D
thanks for helping :)
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I would try the 1.5kw VFD first before spending money on a new 2.2kw drive. Unless you are planning to run the motor at 100% output under a heavy load you probably won't see any difference between the two drives.