DIYbanter - VFD Placement

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Hi,

I want to mount a VFD over the headstock of my lathe,
on the wall. This VFD comes with 1/2 knockouts so I
can cable directly to the VFD. My question is this
a safe place to mount the VFD as far as getting
splattered by any oil from the lathe?
VFD is rated @ IP20 (which I believe is about nothing).

Is there any RF issues that I should be concerned
about that makes mounting the VFD in an enclosure
desirable? I would assume the motor radiates more
noise than VFD would.

If I can mount it there without an enclosure,
then I don't need to remote the display.

Picture in the dropbox:
http://www.metalworking.com/dropbox/VFD_placement.jpg

Thanks,
Wayne D.

Wayne wrote:

Hi,

I want to mount a VFD over the headstock of my lathe,
on the wall. This VFD comes with 1/2 knockouts so I
can cable directly to the VFD. My question is this
a safe place to mount the VFD as far as getting
splattered by any oil from the lathe?
VFD is rated @ IP20 (which I believe is about nothing).

Is there any RF issues that I should be concerned
about that makes mounting the VFD in an enclosure
desirable? I would assume the motor radiates more
noise than VFD would.

If I can mount it there without an enclosure,
then I don't need to remote the display.

Picture in the dropbox:
http://www.metalworking.com/dropbox/VFD_placement.jpg

Thanks,
Wayne D.

An induction motor is totally contactless (at least a 3-phase one is)
and contains no rectifying elements: it'll be about as RF free as
anything could be on an AC line. If the VFD generates RF and lets it
loose on the motor lines then the motor'll radiate -- but only because
of the VFD, not as a fault of the motor.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

On Sun, 20 Mar 2005 16:34:38 -0600, Wayne
wrote:

Hi,

I want to mount a VFD over the headstock of my lathe,
on the wall. This VFD comes with 1/2 knockouts so I
can cable directly to the VFD. My question is this
a safe place to mount the VFD as far as getting
splattered by any oil from the lathe?
VFD is rated @ IP20 (which I believe is about nothing).

Is there any RF issues that I should be concerned
about that makes mounting the VFD in an enclosure
desirable? I would assume the motor radiates more
noise than VFD would.

If I can mount it there without an enclosure,
then I don't need to remote the display.

Picture in the dropbox:
http://www.metalworking.com/dropbox/VFD_placement.jpg

Thanks,
Wayne D.
Greetings Wayne,
VFDs work by switching on and off rapidly. This creates lots of RF
noise. Two machines in my shop have big DC spindles drives. These
rectify (ie change AC to DC) the 230 3 phase input and chop up the
output to change the speed of the spindle. So they are similar in
operation to VFDs. They are really noisy in the AM band. Placed any
closer than about 20 feet an AM radio put out a really annoying
squeal.If mounting in a VFD encloser you will need to be sure it will
get enough cooling. The VFD I have says somewhere in the manual that
it needs a certain amount of cooling and there is a way to figure out
how much air flow is needed to achieve a certain amount of cooling
based on ambient air temp. Can you place some kind of shield in front
of it? I'm picturing a piece of sheet metal 6 inches wider and several
inches longer. Then it could be bent at an angle and screwed to the
wall such that it covers the top, bottom and front while leaving the
sides open. There would be a few inches clearance between the front,
top, and bottom of the VFD and the piece of sheet metal. The sheet
metal would be bent so that when attached to the wall it slopes at the
top so any chips that fall on it will slide off. BTW, there is no 3
phase to my shop so I make it with a rotary phase converter (RPC)
Three machines in the shop need good 60 hertz 3 phase input to make
the servo drives and/or spindle drives work. But all the smaller
machines are 1 HP or less and don't have CNC controls. Since the big
RPC draws about 1500 watts just idling I'm going to start putting VFDs
on the smaller machines and only turn on the RPC when it's needed. I
think they are a great invention and wish they were cheaper when I was
first wiring the shop 8 years ago.
Cheers,
Eric

On Sun, 20 Mar 2005 14:54:37 -0800, Tim Wescott
wrote:

Wayne wrote:

Hi,

I want to mount a VFD over the headstock of my lathe,
on the wall. This VFD comes with 1/2 knockouts so I
can cable directly to the VFD. My question is this
a safe place to mount the VFD as far as getting
splattered by any oil from the lathe?
VFD is rated @ IP20 (which I believe is about nothing).

Is there any RF issues that I should be concerned
about that makes mounting the VFD in an enclosure
desirable? I would assume the motor radiates more
noise than VFD would.

If I can mount it there without an enclosure,
then I don't need to remote the display.

Picture in the dropbox:
http://www.metalworking.com/dropbox/VFD_placement.jpg

Thanks,
Wayne D.

An induction motor is totally contactless (at least a 3-phase one is)
and contains no rectifying elements: it'll be about as RF free as
anything could be on an AC line. If the VFD generates RF and lets it
loose on the motor lines then the motor'll radiate -- but only because
of the VFD, not as a fault of the motor.

And some VFDs generate considerable amounts of RFI..I as a service
technician can sometimes find new customers by listening to my AM
radio in the truck and driving through industrial strips until I get
to the maximum noise. Shrug.. They dont seem to bother TV, FM
etc..but AM radio is pretty common. And Ive seen some older units put
interference into Ethernet networks, though its very very rare.

The manufactures are getting better at making quieter devices.
Btw...shielding them in an enclosure seldom helps, as it radiates via
the motor wiring.

Gunner

Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats.
H. L. Mencken

In article ,
says...
Your lathe is a great looking machine. What brand and model is it?

Is the motor on the carriage for power cross feed?

It's the English-only version of this lathe...

http://www.lathes.co.uk/feeler/

There are a couple other Taiwanese makers of similar
copies. Victor is one and there's another whose name I
can't remember. MSC sells one under their Vectrax name,
Wilton also sells a rebadged version. There's also Ganesh,
which, based on the name, I was afraid might be an Indian
clone, but appears to be Taiwanese as well.

http://www.ganeshmachinery.com/Tool%20Room.htm

Ned Simmons