"Glenn Ashmore" wrote in message
news:l370g.34872$gE.1089@dukeread06...
Here is the best explanation I have found:
http://www.owwm.com/files/PDF/FAQ/ElectricMotors.pdf

--
Glenn Ashmore




Hey Glenn,
big thank you for that link. read the whole thing, still not sure
though if i wired up my motor right. i'm concerned that i didn't hook up
the red wire and the black wire to the pins as specified in the directions.
(previous message w/ link to diagram
http://www.frontiernet.net/~wwixon/fwd-rvse.jpg )

b.w.

The challenge is to identify what the motor terminals are actually
connected to inside the motor.
Apart from start and run windings, there's other stuff like capacitors
and overload switches to confuse us.
Unfortunately the terminals aren't always using the same code
letters/numbers to describe them, but they can be a help.
One system I came across uses codes beginning with U, V and Z, while
another uses codes beginning with P and T.
Here's how I successfully wired up a Taiwanese single-phase 240V motor
for switchable forward/reverse operation, using toggle switches instead
of a drum switch:
http://tinyurl.com/moep7

According to Jordan :
The challenge is to identify what the motor terminals are actually
connected to inside the motor.

Yep -- I think that I have this one decoded. See my other posts
in this thread.

[ ... ]

Here's how I successfully wired up a Taiwanese single-phase 240V motor
for switchable forward/reverse operation, using toggle switches instead
of a drum switch:
http://tinyurl.com/moep7

For whatever reason, I'm not able to access that site at this
time. But one thing which would worry me would be that your design
probably has the assumption that one side of the 240V is grounded. In
the case of US wiring, this is not true. Both sides are hot -- 120V
away from ground and neutral, so both sides need to be switched.

Aha! the image finally arrived. I see another problem as well.
That motor appears to not be designed to operate at 120V -- only at
240V, so the start winding is also a 240V winding. His is a
dual-voltage motor, with two 120V run windings in series for 240V, and
the center tap used to derive 120V for the start winding.

So -- it is a workable circuit for *your* motor and *your*
country's wiring -- but it won't work here in the USA. In particular,
even if he had a motor with a 240V start winding, the RUN/STOP toggle
switch would need to be DPST to open both hot windings for safety
reasons.

Thanks,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

DoN. Nichols wrote:

Aha! the image finally arrived. I see another problem as well.
That motor appears to not be designed to operate at 120V -- only at
240V, so the start winding is also a 240V winding. His is a
dual-voltage motor, with two 120V run windings in series for 240V, and
the center tap used to derive 120V for the start winding.

So -- it is a workable circuit for *your* motor and *your*
country's wiring -- but it won't work here in the USA. In particular,
even if he had a motor with a 240V start winding, the RUN/STOP toggle
switch would need to be DPST to open both hot windings for safety
reasons.

Thanks DoN
I've left out the earth, which is a third wire.
I thought that some parts of the USA had 240V system like here in Australia.
I thought also the drawing might shed some more light on the problem.
Hope I didn't confuse anyone too much.

Jordan

According to Jordan :
DoN. Nichols wrote:

[ ... ]

So -- it is a workable circuit for *your* motor and *your*
country's wiring -- but it won't work here in the USA. In particular,
even if he had a motor with a 240V start winding, the RUN/STOP toggle
switch would need to be DPST to open both hot windings for safety
reasons.

Thanks DoN
I've left out the earth, which is a third wire.
I thought that some parts of the USA had 240V system like here in Australia.

Well ... most parts of the USA have 240V available in the homes
along with 120 -- but most loads are 120, so the design is a center
tapped transformer providing 240 between the ends, and 120 ether side of
the center tap. So -- unlike your 240V, ours has neither side grounded,
but instead floating at 120V above ground. As a result, it changes
what is a safe circuit, and what is not.

I thought also the drawing might shed some more light on the problem.

It did -- for the motors which you have available, and it showed
the principle that you had to reverse the connections to either the
start winding or the run winding -- it doesn't really matter which.
(But his motor was hiding the presence of the windings -- just giving
you wires to move around without showing what they were connected to.
:-) It took me a bit of time to figure out what was really in that
motor, based on what connections were being shown. And I've *worked*
with that kind of motor before.

Hope I didn't confuse anyone too much.

I don't think so. And you were trying to help -- though you
didn't at that time understand the difference between our 240V and
yours.

Thanks,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"Jordan" wrote in message
...
The challenge is to identify what the motor terminals are actually

-snip-

for switchable forward/reverse operation, using toggle switches instead of
a drum switch:
http://tinyurl.com/moep7


thanks for your help Jordan.

b.w.