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Polarize every time?

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mcraeav
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Polarize every time?

#1

Post by mcraeav » Tue Aug 04, 2009 7:55 pm

I have an in-line fuse on my positive bat wire and I often pull it out if the bike is going to set for several days. Do I need to polarize every time I put it back in and start the bike? 62 FLH



awander
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Re: Polarize every time?

#2

Post by awander » Wed Aug 05, 2009 1:03 am

The manual says:

CAUTION: It is advisable to "flash" field coils whenever wires have been removed from teh generator or regulator; or after generator or battery has been removed and is reinstalled."

I think disconnecting the battery wire by removing the fuse would be a "qualifying event".

In any case, it is easy to do, so why not do it?

Bigincher
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Re: Polarize every time?

#3

Post by Bigincher » Wed Aug 05, 2009 4:55 am

I agree.

RICOCHET
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Re: Polarize every time?

#4

Post by RICOCHET » Wed Aug 05, 2009 7:50 pm

I always thought the generator fields would loose polarity only after a long period of time like in several months or years. Is there any damage done if not polarized? If not then to me it would make more sense to see if it's charging before even bothering with it.

JMO

Dick

Bigincher
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Re: Polarize every time?

#5

Post by Bigincher » Wed Aug 05, 2009 9:20 pm

It takes all of about 10 seconds to flash the field windings, and that includes getting the piece of wire out and putting it back. It's such a brainless simple process, I always figure what the Heck can it hurt. Who am I to tell the writers of the Panhead Service Manual that they don't really know what they're talking about...?
The danger of not polarizing the generator is that it "might" actually charge the battery with reversed polarity. POS becomes NEG....

NightShift
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Re: Polarize every time?

#6

Post by NightShift » Wed Aug 05, 2009 10:25 pm

Why pull the fuse?

Just asking respectful,

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Re: Polarize every time?

#7

Post by john HD » Wed Aug 05, 2009 11:50 pm

i have never had to polarize my 2 brush set up.

go figure.

john

Hauula Pan
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Re: Polarize every time?

#8

Post by Hauula Pan » Thu Aug 06, 2009 12:36 am

To answer Nightshift's question of, "Why pull the fuse" I can think of one reason I used to do it. The junk after market relays that stick, when they do it drains the battery. Pulling the fuse opens the circuit and thus stops the battery drain. Since you never really know if the relay has stuck or not your first clue is a dead battery. I now have a good Delco relay and no longer have the sticky relay problem. (Well so far at least)...and yes I flashed the field on start up just to be safe.

108
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Re: Polarize every time?

#9

Post by 108 » Thu Aug 06, 2009 3:57 am

Wont the warning light stay on if the relay sticks? It would be a good habit to always check that the light is off before you walk away.

FlatHeadSix
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Re: Polarize every time?

#10

Post by FlatHeadSix » Thu Aug 06, 2009 12:15 pm

just the opposite 108, if the relay sticks with the main contacts closed and the generator connected to the battery then the GEN light will never come on. There are 2 sets of points in the mechanical relays which work in reverse of each other, when one set is open the other is closed. With the engine off the main contacts should open and disconnect the generator armature from the battery and the other set will close supplying ground to the idiot light.

The check to see if the relay is stuck when you park the bike would be to switch the engine off and then turn the switch back on again, if the OIL light comes on and the GEN light does not it would tell you the relay is stuck.

mike

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Re: Polarize every time?

#11

Post by NightShift » Thu Aug 06, 2009 3:46 pm

Please explain once more the reason to pull the fuse?
The batterys gonna die either way.

I'd rather find it dead in the garage than down the road.

Just asking respectful again,

108
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Re: Polarize every time?

#12

Post by 108 » Thu Aug 06, 2009 5:29 pm

Of course, your right Flatheadsix. I was thinking of something else

Hauula Pan
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Re: Polarize every time?

#13

Post by Hauula Pan » Fri Aug 07, 2009 5:33 pm

Just did a little experiment and thought I'd post the results. 52 FL, 32E 3 Brush, Mechanical Relay, 6 volt system. Disconnected the positive battery cable and hooked it right back up, started the bike and Gen. light stayed on. Flashed the field, touched wire from A - on generator to the positive battery terminal and light went out. a couple restarts and still worked fine. Just to see what would happen I disconnected the positive cable again and reconnected it. Restarted the bike and once again the Gen. light stayed on, flashed the thing again and the light went right out. So I would say that Anytime you disconnect the battery for any reason for any length of time you need to flash the gen. This may work differently with other set ups but with mine as listed above these are the results. So to answer the original question of, "Do I need to polarize the gen. every time the battery is disconnected?" I would say YES, if you are running a 6 volt, 32E with mech. relay. Can't tell you about 2 brush or 12 volt etc. But mine definitely needs to be flashed Anytime the battery is disconnected and reconnected, even for just a couple minutes. This could be good info. for those that don't have a light hooked up, as they wouldn't know if the thing was working or not and taking the few seconds it takes to go ahead and touch a wire from the A - post to the pos. bat. post only makes sense. Its simple, quick, and makes sure the gen. is properly polarized. So as the saying goes, "Just do it".

Bigincher
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Re: Polarize every time?

#14

Post by Bigincher » Fri Aug 07, 2009 5:51 pm

Question to you, Haluua Pan ---

Did you flash it with the motor running? I have always done it with the motor NOT running, before I start it. Never even occured to me to do it with the motor running--- and also have never had any problems doing if this way, for the past................... oh, 35 years.
Just curious--- and thanks for the informative post.

FlatHeadSix
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Re: Polarize every time?

#15

Post by FlatHeadSix » Fri Aug 07, 2009 8:05 pm

As Hauula said: "just do it!", its quick, its easy, it doesn't cost anything but a few seconds of your time and it almost always gaurantees good results.

If anyone is interested here is the logic behind why it works. The 32E has two separate field coils, one is grounded by the 3rd brush, the other is only energized when you move the ignition switch to the 2nd click and turn on the lights. NEITHER one is energized when the engine is first started and the ignition switch is in the 1st position. The generator MUST rely on the residual magnatism in the cast iron pole shoes to begin producing electricity, once the output of the 32E is above the battery voltage it will trip the relay and close the circuit between the battery and the generator: idiot light goes out and the 1st (regulating) field coil kicks in and gets things going inside the generator. When you "flash" the generator it forces current through the field coil producing a magnetic field which actually magnatizes the cast iron pole shoe inside the generator body. Without this residual magnatism, or if the shoe polarity is reversed, the generator will not "self-energize" or produce enough current to close the relay.

Getting back to Hauula's experiment; if you disconnect, reconnect, don't flash, start the engine and the GEN light stays on you can force the generator to start charging by turning the lights on which energizes the 2nd (shunt) field coil. The GEN light will go out because you have essentially just done the same thing as flashing or polarizing the generator using a jumper. This all assumes, of course, that you have everything connected correctly and the battery is at or near 6 volts. Once the light goes out you can switch the ignition back to the 1st position and the GEN light will stay out and the charging system will operate as normal.

Remember also that the mechanical relays have 2 separate windings in them. The "big" coil in the relay initially requires a rather large voltage potential to create enough magnetic force to close the relay, once the relay closes a smaller coil takes over which draws much less power (the "holding current") and keeps the relay closed until you switch off the engine or the rpm drops below the point where the generator output is less than the battery voltage.

mike

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