Thread: vfd question for my lathe motor

im having trouble with the 1 hp motor tripping the vfd( huanyang 1.5 kw) when only using light loads on my lathe.
it appears that its an over current fault ( set at 1.76) it shuts down when the vfd shows about 2,2 amps
i have read in the cnc forums that they set the motor current to maximum ( 7 amps) is this advisable
john

Hi John,
Is this at 50Hz? I have this sort of problem when I get down under about 15Hz.
(not much help I know but the answer may help others give you an answer)

Stuart

thanks stu i just did a kill it or fix it experiment i cranked the amps in the parameters up to 5 and then watched how high the reading would go turning a piece of caste on slowest back gear but realy making it work; it got to about 3 the motor wasnt getting hot evrything seems ok so maybe that all it needs ( perhaps set it at 4 just to be on the safe side )
john

What's the amperage value on the motor? You're supposed to enter this value as max current.

bryan the motor plate says 1.76 amps (.75 kw) this is the second motor i have tried and both shut the vfd down on only light cuts when the amps as indicated on the motor plate are entered .it usually shuts down around the 2.2 amps .
for a motor this size i should be able to take much deeper cuts on the slow speed ( i have 2 other hercus lathes with single phase motors to compare it against )
as i said in the last post upping the amps to 4 seems to have solved the problem, i got this suggestion fronm the cnc forum where the same vfd is used on cnc spindles ( they program in 7 amps )
but welcome all suggestions
john

Hi John,

The 7 amps would be for 1.5Kw motors. At the front of the manual they have a table of inverter models that lists motor size and inverter capacity

(I tried to insert the table but didn't work...) Lets try a jpeg...



I don't think that the 3 or 4 amp current limit will damage your motor, certainly won't hurt the VFD.

That said, Brian is correct, the normal procedure is to use the motor nameplate current, but that assumes 50Hz...

Regards
Ray