[sci.electronics] Electric motor connections

steve@cs.UAlberta.CA (Steve Sutphen) (12/03/90)

Is there a standard for electric motor connections?  I have a 1HP 
syncronous A/C motor (GE 5KC47PG1207EX) that I retrieved from an
old disk drive.  I would like to turn this into the drive motor for 
my table saw, but I do not have any wiring diagrams for it (it does say
that it requires 187-253V at 9.0A).  The problem is that the way it was
hooked up used more than 3 wires (it is a single phase motor so I would
expect 2 current carrying wires and a safety ground).  There are 5 wires
(plus safety ground) comming into the motor.  I traced out where all the
wires went, but that didn't help much as 3 went to the field windings, one
went directly to the motor start capacitors (two in series).  Here is a
schematic of what I have reverse engineered so far.


4-------------------------------------- to field winding `A'

V--------||---||-------->|
                         |
                         |
2_________________H______|------------- to field winding `A'

3-------------------------------------- to field winding `B'

1-------------------------------------- to field winding `B'

The numbers are the Faston terminal numbers, the `V' is a violet wire that
goes to the motor start caps, the `->|' is the contact that opens when 
the motor is up to speed, and the `H' is the thermal protection.  There is
a sticker on the motor indicating that it is wired for CW and low voltage.
What I would like to do is figure out how to wire this up for 220 (or is 
it 208V).  I may need to change the rotation direction too (actually I 
have another motor that runs off of 110V that I would like to change the
direction on if anyone knows how).

Any help would be appreciated.
	steve@cs.ualberta.ca

grege@gold.gvg.tek.com (Greg Ebert) (12/04/90)

In article <1990Dec2.220920.14435@cs.UAlberta.CA> steve@cs.UAlberta.CA (Steve Sutphen) writes:
> [...]
>
>4-------------------------------------- to field winding `A'
>
>V--------||---||-------->|
>                         |
>                         |
>2_________________H______|------------- to field winding `A'
>
>3-------------------------------------- to field winding `B'
>
>1-------------------------------------- to field winding `B'
>
I havn't worked with the exact motor you have, but I've tinkered with a
similar one. Hope this helps.

These guys look like a (from a circuit-sense) as :


AC line -----------*------ switch --| |-----
		   |                        |
                 Stator                   Start
		 Coil                     Coil
		   |                        |
		   |                        |
AC line -----------*-------------------------


The switch is closed when the RPM is low (~75% rated speed). The direction of
rotation is determined at power-on. If you disconnect the starter winding, you
can manually start a motor in either direction. Better yet, just switch the
'polarity' of the stator winding with respect to the start winding to reverse
the direction.

To get your motor to run:

	Connect terminal 2 to AC line.
	Connect terminal V to terminal 1
	Connect terminal 4 to AC neutral
	Connect terminal 1 to AC neutral

To reverse direction, interchange 1 and 3.