On Wed, 21 May 2008 08:12:10 +0200, "Steve Lusardi"
wrote:

Andy,
If the motor is an induction motor and single phase, rotation often can be
changed by reversing the armature end for end. This is especially true with
centrifugally switched, shaded pole starting. Swapping the wires on the
start capacitor will not change the start direction on capacitor start
motors. Reversing single phase motors have two start windings, one for CW
and one for CCW. Direction is determined which start winding is engaged with
a switch. Motors that have only a single start winding can only be reversed
by rotating the run field winding. This can only be done if the end plates
are identical.
Steve

"Andy Asberry" wrote in message
.. .
The three horse motor on my compressor died. I've had this big 5.5 hp
Marathon for just such an occasion. It is 230v 1ph 215T frame (if that
matters).

I've downloaded Marathon's installation and operation manual. Under
changing rotation, it says follow the diagram on the motor. Surprise,
surprise. No diagram. All wires are numbered. It is currently running
CW.

Any help from the gallery? I have new breakers!

--Andy Asberry--
------Texas-----


This advice has got a bit garbled.

Single phase SHADED pole motors have no accessible
start windings (they are the short circuited copper rings). They
are sometimes (rarely) fitted with two MAIN windings - one for
each direction. The construction normally permits direction
reversal by mechanical 180 deg rotation of the stator with no
change of the rotor shaft connection to the load

If the rotor is reversed end for end and the drive taken
from the previously unused rotor shaft end the drive direction
will remain unaltered. This is also true for single and three
phase induction motors.

Single phase motors with split phase or capacitor start
have a main winding and a smaller start winding. Rotation can be
reversed by reversing the connections to either (NOT both) the
main or the start winding. Once the motor is up and running the
start winding is no longer connected so running reversal is not
possible.

A 5.5HP motor is almost certainly capacitor start or
capacitor run. To reverse you need to identify the two ends of
either the main winding or the start winding and reverse one of
them. To sort this out we need more information - you need to
post the existing connections to the numbered wires.

Jim