Polarizing 6V Generators
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=172804
Printed Date: 30 May 2025 at 1:00pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Polarizing 6V Generators
Posted By: fleeter allis fan
Subject: Polarizing 6V Generators
Date Posted: 14 Jul 2020 at 5:12pm
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Hi All. A while ago, I was having some generator and some charging issues. Among other things, I read and learned about polarizing the generator. This is done, as I learned, by grounding the field winding on the generator, and then briefly shorting the "Bat" terminal to the "Gen" terminal on the cut out relay until you get a small spark. I have done this occasionally in the past, but I really don't know when it should be done. For various reasons I have had the batteries in and out of two of my tractors several times recently. I have been polarizing each time I reconnect the batteries, before starting the tractor. Is this necessary? Can anyone tell me when and how often this should be done? Thanks ------------- I'm a man...and I can change...if I have to... I guess. '44 B, '46 WF, '49 G, 810GT, 916H, 620 |
Replies:
Posted By: DennisA (IL)
Date Posted: 14 Jul 2020 at 7:00pm
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It should not have to be done very often. Last I did my CA I was 20 years ago. Do it only when it’s not charging. ------------- Thanks & God Bless Dennis |
Posted By: steve(ill)
Date Posted: 14 Jul 2020 at 7:48pm
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YEP... i doubt i have done it once every 10 years. ------------- Like them all, but love the "B"s. |
Posted By: fleeter allis fan
Date Posted: 15 Jul 2020 at 8:04am
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It looks like I am overdoing it. I guess as long as it charges properly, I won't worry too much about it. Thanks.
------------- I'm a man...and I can change...if I have to... I guess. '44 B, '46 WF, '49 G, 810GT, 916H, 620 |
Posted By: jange01
Date Posted: 15 Jul 2020 at 10:57am
Only need polarizing if the generator has lost it's residual magnetism. This will be rare. It is said to do it after a rebuild, or extended times of no battery hooked up. Though I have seen them charge right up after sitting for years on the shelf. That being said, when done properly polarizing will not hurt a generator. Be aware if the generator is am A circuit or B circuit. This is how the generators output is controlled by the regulator, regulating the field current. 'A' circuit generators are controlled by the regulator varying the ground to the field. In 'B' circuit generators the regulator applies current to the field, which is internally grounded. Keep in mind many generators have been swapped around over the years. If all else id OK with the generator and it is not charging, polarizing will usually fix the issue
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fleeter allis fan wrote:Posted By: Luke114
Date Posted: 15 Jul 2020 at 12:45pm
| Some good advice on charging issues that was passed on to me was to clean your regulator contacts first. This is especially useful when the generator has not operated in a long time, meaning neither has the regulator. A very small bit of oxidation will cause problems. |
Posted By: DiyDave
Date Posted: 15 Jul 2020 at 5:11pm
I was told it only needs done, when changing out a gen or reg. I always forget which terminals to jump, I do it so rarely... Thank god fer youtube... ------------- Source: Babylon Bee. Sponsored by BRAWNDO, its got what you need! |
Posted By: mdm1
Date Posted: 15 Jul 2020 at 6:09pm
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The way I remember it is Boy to Girl but never to Female. I have to admit I really don't polarize mine. ------------- Everything is impossible until someone does it! WD45-trip loader 1947 c w/woods belly mower, 1939 B, #3 sickle mower 1944 B, 2 1948 G's. Misc other equipment that my wife calls JUNK! |
Posted By: DaveKamp
Date Posted: 15 Jul 2020 at 9:55pm
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Also note that just as the generator requires residual magnetism to BUILD it's initial generation, mechanical regulators ALSO hold residual magnetism, as a side-effect of their (polarized) DC operation. This doesn't mean they won't operate without residual magnetism, they simply develop it, and as such, the residual field augments the active field in regular operation, and thus, adjustment of the regulator is affected by it's augmentation... OR IF one reverses polarity on a tractor, the residual magnetism will COUNTERACT the regulator's polepieces (cutout and regulate), so the polepiece of the regulator must be exercised and given time to reverse as well, before one can expect the regulator and generator combination to be stable. So the short story... if you haven't run it in a LONG time, or you've reversed polarity of the tractor, give it some time to settle in, before attempting to 'dial in' the regulator, and expect to have to bring up the throttle and rap the regulator with a screwdriver handle a few times to 'wake it up'. ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |