In article .com,

z wrote:

On Apr 10, 10:04 am, Rick Blaine wrote:
deke wrote:
Most motors can NOT be reversed.

I would qualify that. I think if they are designed to run in reverse,
they will
have separate windings for each direction, with only one of the windings
energized at a time.

Vague memories... if it has no windings in the rotor, as many don't,
it just runs on phase lag and hysterisis or some such and is
unidirectional. If there are windings in the stator and the rotor,
then presumably they can be flipped relative to each other... don't
know how relevant each type is to the size of motor that might be in a
house fan.


Reversible induction motors will generally have a data plate with
wiring connections diagrammed to show how to reverse direction. If it
is a shaded-pole motor or other design that is not electrically reversible,
it is sometimes possible to dissassemble the motor, turn the stator
180 degrees, and reassemble to reverse the direction. OTOH, if the
attic access and the fan are anything like the one in my house,
I'd probably just pony up the $60 or $80 for a whole new fan assembly
and be sure it would work for a while, I just don't enjoy working in a
crouched position standing on top of a square of plywood layed over the
ceiling joists in a space full of blown-in cellulose insulation, dust, and
low light.



--
There are no stupid questions, but there are lots of stupid answers.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org