Electric motor direction change
Electric motor direction change
(OP)
Hello. I have to admit this is probably way too simple for most in this forum but it's not my specialty so I am trying to learn. Bare with me please. My question is, I am trying to change the drection of a motor I pulled from a small orbital sander. I would like the motor to operate in both directions. I realize that it wasn't designed to, but I also know it can be re wired to do so. Can anyone give me an idea of how to do this and any schematics or simple diagrams of how a motor like this is normally wired and what wires in it need to be changed. It's obviously an AC motor operating at 120 volts. Any help would be greatly appreciated. I am trying to learn all I can about electric motors and this forum is just superb. Hats off to all the pro's who take the time to help.
Thank you in advance.
Michael
Thank you in advance.
Michael





RE: Electric motor direction change
check out this page for some useful diagrams:
http://www.lmphotonics.com/single_phase_m.htm
otherwise,leave a few more details about the motor and wiring you have got and I will try to help.
Jeff
www.motors-direct.co.uk
RE: Electric motor direction change
RE: Electric motor direction change
Whoops
Jeff
www.motors-direct.co.uk
RE: Electric motor direction change
"Venditori de oleum-vipera non vigere excordis populi"
RE: Electric motor direction change
RE: Electric motor direction change
"Venditori de oleum-vipera non vigere excordis populi"
RE: Electric motor direction change
By the way. What does that line in your posts mean?
RE: Electric motor direction change
Its all getting clearer now....sounds like a series wound type of motor....in which case,,,reversing the brush leads should reverse the rotation.....although....most armature motors will run slightly better in one direction than the other!!
Jeff
www.motors-direct.co.uk
RE: Electric motor direction change
A permanent magnet commutator motor only works on dc and will reverse if you reverse the motor leads. A Universal motor (so named because it can run from ac or dc) differs only in that the field flux is supplied by stationary coils instead of a permanent magnet, these field coils being connected in series with the armature.
The direction of a Universal motor can be reversed by reversing EITHER the direction of current in the rotor (the armature) via the brushes, or in the stator (field windings). If you reverse the current in BOTH you get no change in direction, hence when you apply ac to the motor, the rotating force will be in the same direction for both half cycles of ac because you are simultaneously reversing current direction in both armature and field.
So as motorsdirect says, you can simply switch over the brush leads (or the field winding leads) to reverse it. This applies even if the motor has an integral rectifier (they are sometimes fitted, possibly this is to reduce sparking - maybe someone else could comment on this).
Note the motor will generally run on lower voltage when driven of dc (the inductance limits the current on ac). You can experiment with a low voltage dc power supply.
RE: Electric motor direction change
My sig line roughly means "Snake-oil salesmen cannot thrive without an ignorant populace".
"Venditori de oleum-vipera non vigere excordis populi"