# Perm 132 72V CCW Rotation



## theSookman (Apr 7, 2012)

Hello all, 

I googled around to try to find a good answer to this question to no avail, so here it goes:

I have a perm 132 that I'm planning on using in a high performance gasoline-electric generator @ 72V. The problem is that the engine rotates CCW, and the perm is only guarenteed to run CCW @ 48V. I opened up the brush holder and took a look, I noticed that they were at an angle. There was no easy way I could see the reverse this angle.

As far as I can tell, the only major issue may be excessive brush wear, which I don't really care about as this is not a long term machine. 

I wanted to know what the problems would be running this motor like this? Does anyone have any experience with this motor? Modifications I could make? 

Thanks, 
- Josh

PS - I emailed Perm, but haven't heard back yet.


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## major (Apr 4, 2008)

theSookman said:


> I have a perm 132 that I'm planning on using in a high performance gasoline-electric generator @ 72V. The problem is that the engine rotates CCW, and the perm is only guarenteed to run CCW @ 48V. I opened up the brush holder and took a look, I noticed that they were at an angle. There was no easy way I could see the reverse this angle.
> <snip>
> I wanted to know what the problems would be running this motor like this? Does anyone have any experience with this motor? Modifications I could make?


Hi the,

The angle of the brush centerline to the axis of rotation of the comm is unimportant with regards to rotation direction. The angular position of the contact with comm surface relative to the field is what matters. This commutation angle is advanced to compensate for armature distortion in a motor. In a generator, the armature current is reversed so that the brush position (commutation angle) needs to be retarded.

One direction for the motor; opposite for generator. 

Regards,

major


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