"Bob La Londe" wrote in message
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wrote in message
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To all youse high speed spindle guys,
I have now a new 2.2KW VFD and matching 24000 RPM spindle motor. I am
wondering how important line and load reactors are for this setup.
Especially the line reactor because the motor/VFD combo is supposed to
be matched and because the motor wires will be short, 6 feet or so.
From looking online I have determined that a reactor rated at 12 amps,
2.5 mh, and 5% impedence is optimal. Can a reactor with a larger
current rating be used? Also, since the VFD can be connected to single
phase power and I want to use that option, I think I need to use a
reactor with a higher current rating. 18 amps instead of 12, right? I
haven't seen any single phase reactors yet on ebay which is why I am
asking. On the output side I am concerned with noise making problems
for the CNC mill (a Fadal 15XT) that the spindle will be installed in.
Will a reactor help with this sitaution? Do I really need one with
such a small (2.2 KW) motor?
Thanks,
Eric

From what I have read you DO NOT need a line reactor for short runs. Some
writers disagree about what is considered short, but most say ten feet or
less. Some users have reported no problems with slightly longer runs. I
do use a shielded high flex cable between the VFD and the motor with the
shield going to the same common ground as the VFD.

I only do that on my high speed spindles. The Hurco is wired with stranded
THHN in flex conduit, and then open inside the head.

I rarely get calculated loads anywhere NEAR my self determined limit of
3HP anyway.