Farm Equipment - how to polarize a three brush generator on C

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how to polarize a three brush generator on C

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=153835
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Topic: how to polarize a three brush generator on C

Posted By: John426
Subject: how to polarize a three brush generator on C
Date Posted: 10 Sep 2018 at 4:42am

I would like to polarize the generator on my Allis C. It is a 3 brush genrator 6 volts;

How i can do it?

Thanks

Replies:

Posted By: Brian Jasper co. Ia
Date Posted: 10 Sep 2018 at 7:21am

Momentarily jump across the cutout relay on the generator. All it takes is a quick spark. Use a piece of wire about the same thickness as on the tractor.

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"Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford

Posted By: Gerald J.
Date Posted: 10 Sep 2018 at 9:27am

Do that polarization before you start the engine the first time after installing the repaired or shop tested generator.

The three brush generator is normally used without a voltage regulator and the function of the third brush is to act as a current limiter so the generator won't be overworked by a low battery. Its up to the operator to back off the generator with the light switch to keep from over charging the battery but also to be sure the battery is full charged.

Gerald J.

Posted By: steigerbro24
Date Posted: 10 Sep 2018 at 12:14pm

Is determining if its a 2 brush or 3 brush as simple as opening the band and counting the brushes?

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5 Steigers, 7 John Deeres, 8 Internationals, 4 Case tractors and combines and 1 Oliver
........... Oh wait they're all 1/64.......and a real '44 B

Posted By: Gerald J.
Date Posted: 10 Sep 2018 at 6:26pm

Yes its that easy. But its very likely to be a three brush generator if it has only a cutout and no voltage regulator. The third brush causes a current limiting operation from the magnetic field from the third brush and protects the generator from a battery that would draw more current than the generator is built for. A voltage regulator with three coils inside uses one for cutout, one for voltage regulation, and one for current limiting so the third brush isn't needed but it doesn't hurt much either.

Gerald J.

Posted By: John426
Date Posted: 11 Sep 2018 at 2:35am

Gerald , does it means , that il i put a three coils voltage regulator, i can remove the third brush?

Posted By: Gerald J.
Date Posted: 11 Sep 2018 at 9:49am

Yes the generator will work fine with the third brush and the voltage regulator with current regulator. If the current setting for the current regulator part of the voltage regulator matches the design current rating of the generator, the third brush isn't needed. Getting the voltage regulator with the proper current rating is another variable to be matched along with the wiring of the field that is not so common with the AC generator.

Gerald J.