I brought home a Clausing 1301 lathe not long ago as a new addtion to
the home shop. It has a Doer 5hp 2 speed 208V 3ph motor. It runs
fine off the the 15hp phase converter I have for the larger lathe and
mill, but where I want to put it in the shop I don't have any 3 phase
wiring installed. There is a 220V 1phase outlet in place but I can't
find any 5hp 1 phase to 3 phase VFD's for less than ~800 bucks.
Since I'm not going full load a static converter would be fine -but
apparently they won't work on two speed motors. Anyone try this with
success? I'm also worried about using a VFD with a non VFD rated
motor, since this motor is a special mount ie. v exp to replace.

I am using a VFD on my logan/powrmatic lathe, I kept the original motor, so
far, no problem - so I don't think you need to get too excited about VFD
rated motors - I use a static converter on my mill because it has a
multispeed gear box, and one capacitor and one relay is a heck of a lot
cheaper than a VFD (and also it achieves it's "rapids" function by reversing
the traverse motor, which would not be to the liking of a VFD even if I
added one)
"oldjag" wrote in message
...
I brought home a Clausing 1301 lathe not long ago as a new addtion to
the home shop. It has a Doer 5hp 2 speed 208V 3ph motor. It runs
fine off the the 15hp phase converter I have for the larger lathe and
mill, but where I want to put it in the shop I don't have any 3 phase
wiring installed. There is a 220V 1phase outlet in place but I can't
find any 5hp 1 phase to 3 phase VFD's for less than ~800 bucks.
Since I'm not going full load a static converter would be fine -but
apparently they won't work on two speed motors. Anyone try this with
success? I'm also worried about using a VFD with a non VFD rated
motor, since this motor is a special mount ie. v exp to replace.



--
Posted via a free Usenet account from http://www.teranews.com

On Thu, 27 Dec 2007 19:34:41 -0800 (PST), oldjag
wrote:

I brought home a Clausing 1301 lathe not long ago as a new addtion to
the home shop. It has a Doer 5hp 2 speed 208V 3ph motor. It runs
fine off the the 15hp phase converter I have for the larger lathe and
mill, but where I want to put it in the shop I don't have any 3 phase
wiring installed. There is a 220V 1phase outlet in place but I can't
find any 5hp 1 phase to 3 phase VFD's for less than ~800 bucks.

Almost all VFDs in this size range will operate on single phase,
regardless of whether or not they're rated for single phase input,
though it's considered wise to derate the drive when doing so. If it
were my lathe, I'd be comfortable with a 7.5HP drive.

For example...
http://offer.ebay.com/ws/eBayISAPI.d...m=140193665999
I have no idea whether that specific drive is suitable. The most
obvious bit of missing info is whether it's a 230 or 460 volt unit.
Most mfrs have manuals and full specs online.

Since I'm not going full load a static converter would be fine -but
apparently they won't work on two speed motors. Anyone try this with
success?

I've tried it *without* success. One of my lathes has a 2-speed motor,
and it was not happy with a static converter.

I'm also worried about using a VFD with a non VFD rated
motor, since this motor is a special mount ie. v exp to replace.

Unless it's a very old motor, I wouldn't be concerned.

--
Ned Simmons

oldjag wrote:

I brought home a Clausing 1301 lathe not long ago as a new addtion to
the home shop. It has a Doer 5hp 2 speed 208V 3ph motor. It runs
fine off the the 15hp phase converter I have for the larger lathe and
mill, but where I want to put it in the shop I don't have any 3 phase
wiring installed. There is a 220V 1phase outlet in place but I can't
find any 5hp 1 phase to 3 phase VFD's for less than ~800 bucks.
Since I'm not going full load a static converter would be fine -but
apparently they won't work on two speed motors. Anyone try this with
success? I'm also worried about using a VFD with a non VFD rated
motor, since this motor is a special mount ie. v exp to replace.

VFDs and two speed motors don't play well together IIRC.

GWE

--
Posted via a free Usenet account from http://www.teranews.com

On Dec 27, 7:34 pm, oldjag wrote:
I brought home a Clausing 1301 lathe not long ago as a new addtion to
the home shop. It has a Doer 5hp 2 speed 208V 3ph motor. It runs
fine off the the 15hp phase converter I have for the larger lathe and
mill, but where I want to put it in the shop I don't have any 3 phase
wiring installed. There is a 220V 1phase outlet in place but I can't
find any 5hp 1 phase to 3 phase VFD's for less than ~800 bucks.
Since I'm not going full load a static converter would be fine -but
apparently they won't work on two speed motors. Anyone try this with
success? I'm also worried about using a VFD with a non VFD rated
motor, since this motor is a special mount ie. v exp to replace.


VFD's do not work well with a switch between the VFD and the motor.
If you are very careful, and never switch the motor speed switch,
while the VFD is powering the motor, you may be OK.
That said, my motor supplier claims that any NON-VFD rated motor will
always fail, sooner or later. I have had no failures, yet.

I have 2 VFD's working fine, I love them. One on a VFD rated motor,
one not.
Dave

Mechanical Magic wrote:
On Dec 27, 7:34 pm, oldjag wrote:

I brought home a Clausing 1301 lathe not long ago as a new addtion to
the home shop. It has a Doer 5hp 2 speed 208V 3ph motor. It runs
fine off the the 15hp phase converter I have for the larger lathe and
mill, but where I want to put it in the shop I don't have any 3 phase
wiring installed. There is a 220V 1phase outlet in place but I can't
find any 5hp 1 phase to 3 phase VFD's for less than ~800 bucks.
Since I'm not going full load a static converter would be fine -but
apparently they won't work on two speed motors. Anyone try this with
success? I'm also worried about using a VFD with a non VFD rated
motor, since this motor is a special mount ie. v exp to replace.



VFD's do not work well with a switch between the VFD and the motor.
If you are very careful, and never switch the motor speed switch,
while the VFD is powering the motor, you may be OK.
That said, my motor supplier claims that any NON-VFD rated motor will
always fail, sooner or later. I have had no failures, yet.

If the motor is a 220/440 V motor, it has heavier insulation,
and will last longer with a VFD. You can also put in a set of
inductors to reduce the high voltage spikes reaching the motor.

Jon

I am not an expert in VFD - but they vary the frequency to change the
speed. Some motors are designed for just that and have special alloy
metal. Older and non-vfd types respond differently to other than 60 or
50 Hz - the base frequency they were designed for.

Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Life; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Jon Elson wrote:
Mechanical Magic wrote:
On Dec 27, 7:34 pm, oldjag wrote:

I brought home a Clausing 1301 lathe not long ago as a new addtion to
the home shop. It has a Doer 5hp 2 speed 208V 3ph motor. It runs
fine off the the 15hp phase converter I have for the larger lathe and
mill, but where I want to put it in the shop I don't have any 3 phase
wiring installed. There is a 220V 1phase outlet in place but I can't
find any 5hp 1 phase to 3 phase VFD's for less than ~800 bucks.
Since I'm not going full load a static converter would be fine -but
apparently they won't work on two speed motors. Anyone try this with
success? I'm also worried about using a VFD with a non VFD rated
motor, since this motor is a special mount ie. v exp to replace.



VFD's do not work well with a switch between the VFD and the motor.
If you are very careful, and never switch the motor speed switch,
while the VFD is powering the motor, you may be OK.
That said, my motor supplier claims that any NON-VFD rated motor will
always fail, sooner or later. I have had no failures, yet.

If the motor is a 220/440 V motor, it has heavier insulation, and will
last longer with a VFD. You can also put in a set of inductors to
reduce the high voltage spikes reaching the motor.

Jon