Re: [CAD_CAM_EDM_DRO] Geckos and VFD in same enclosure?

Lance Hopper wrote:

> I'm getting a plan together for wiring up a Gecko servo system
>with a 240 3phase AC drive/motor. I had initially planned to wire up
>ALL the system electronics in a single large enclosure. I've heard
>that EMI/RF noise can be bad with AC drives. Should I mount the AC
>drive all by itself(very close to AC spindle motor), on the far end
>of the machine from the rest of the electronics (PC/breakout/geckos
>etc...)?
>
>

It is hard to say. Some people have major problems with this, others don't.
The VFDs, for the most part, ARE enormous noise generators. If you do
the wiring carefully, and separate all signals wires from the VFD wires, you
should be OK. It probably makes sense to supply separate power to
the VFS than the rest of the system. Likely, you'd power the VFD from
240 and the servo system and computer, etc. from 120.

> Mounted in an isolated condition like this, should I still buy an
>expensive $109 EMI filter for my AC drive?
>
>

You might need it, still. Although, I have used an assortment of line
filters
salvaged from equipment at MUCH lower cost. I had to put a filter on
my mill's VFD because it drove the computer in my air compressor crazy,
and also put some hash or snow on the CNC computer's screen. Depending
on the size of the VFD and spindle motor, you should be able to find a line
filter module for less.

Really, where you mount it is not so much of an issue. I have mine
bolted to
the wall behind the mill. It doesn't get dirty, and the wires are of
reasonable
length. This also keeps the display visible to me, so I can set the
frequency
of the drive with the manual knob I have mounted on the mill.

Jon