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Generator Adjustment

Electrical issues
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Sadist
Posts: 18
Joined: Tue Jun 28, 2005 11:54 pm

Generator Adjustment

#1

Post by Sadist » Wed May 23, 2007 2:48 pm

Hey gang..
My panhead (1951, 3 brush 6V) took a crap last week, running at night she started missing pretty bad at low rpm, light started dimming, would run better with the light shut off... was 25 miles from home, at night, i called it a night and got rescued... yanked the genny out and to the rebuilder. Found the armature to be wasted... found a rewind.. got a solid state cut out, and a gel 6V battery (had it with sub standard india made units, that destroy armatures).

All's back together and it runs well, the gel holds a charge like crazy, bright lights all seems great...

but i want to dial in the generator, what's the best method of checking amperage?
I beleive the deal is to remove negative wire to battery and put an ammeter between, neg post and ground, remove wire to gen terminal on cut out, jump gen terminal to battery positive, turn on all lights (high beam) and run bike, revving to approx 2K.

do i have any concerns with the gel, is it more resiliant to higher amperages?

Thanks!



pan50head
Posts: 49
Joined: Wed Mar 21, 2007 5:48 pm
Bikes: 1950 FL
Location: Seattle

#2

Post by pan50head » Wed May 23, 2007 4:25 pm

I just went through just what you are doing. Don't do it. The stock-style 6 volt battery is rated at 24 amp-hours. The gel battery I used was rated at 12 amp-hours. The problem is that the cutout can't figure this out. Because of the confusion, the generator charges at 10 to 12 volts. You will start popping your lights, and then your armiture will croak. In the meantime, if you have a solid state cutout, it will be history. After going through all of this hassle, I talked with a knowledgeable generator repairer and he told me what I described above.

If there was enough room in the oil bag to put two 12 amp-hour batteries, it should work.

My solution was to convert a 32-E to a 12 volt 2 brush and use a solid state, stock-looking regulator sold by V-Twin. I use an 8 amp-hour 12 volt sealed battery. I have ridden the bike about a 1,000 miles with this set-up and so far, so good. I have brighter lights, better spark and a better running bike.

I cut the inerds out of a stock 6 volt battery. All of the parts look stock.

pan50head
Posts: 49
Joined: Wed Mar 21, 2007 5:48 pm
Bikes: 1950 FL
Location: Seattle

#3

Post by pan50head » Wed May 23, 2007 4:28 pm

I should have further explained. I cut the insides out of a stock 6 volt battery and inserted the 12 volt gel battery. I EVEN PUT A FUSE IN THE LINE INSIDE THE BATTERY. WHAT A CONCEPT.

FlatHeadSix
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#4

Post by FlatHeadSix » Wed May 23, 2007 5:45 pm

Pan50Head..
the problem description from your generator repair guy doesn't make sense to me, I'd like to hear his more technical explanation. The cutout in a 3-brush 32E system doesn't do anything more than "cut out" when the generator is not producing electricity, all it does is disconnect the generator from the battery when the engine is not running. The 32E's are internally regulated, by the design/construction of the armature windings, field windings and position of the 3rd brush. Battery capacity (12 amp/hours vs 24 amp/hours) should have no effect, as long as it is a good battery. Battery CONDITION, on the other hand, will make a big difference.

Your dial in procedure should work Sadist, if the contacts in the cutout are good and the cutout is working you should not have to "jumper" anything, the "BAT" terminal on the relay is already wired straight to the battery positive terminal. The 32E has 2 field windings, they are both different and they are not always energized. When you turn the ignition switch to the 1st click and start the engine only one field winding is working and the generator out put is quite low. When you turn the switch to operate the lighting system it energizes the 2nd field winding and increases the out put to match the higher load.

The dial in you refer to is to try to match the generator output to the load without overcharging the battery. Some bikes have more lights than others, that's why the 3rd brush is mounted to the slotted ring. Start it up, turn on the number of lights you will usually run and check the amps. If you will be running the bike continuously for long periods you want to adjust on the lower side, about 1 or 2 amps is all you need or you will boil the battery dry on long runs. Moving the 3rd brush closer to the "Relay" terminal should increase output, moving it away (counterclockwise) should decrease it.

good luck!

Sadist
Posts: 18
Joined: Tue Jun 28, 2005 11:54 pm

#5

Post by Sadist » Wed May 23, 2007 6:43 pm

Thanks... I did check the AH rating of the battery i got, it's 18AH, the junk indian made battery is rated at 22AH. The junk indian (like turban, not like squaw) battery caused my trouble to begin with.

My book was unclear on the amperage testing procedure. I thought it strange that it said to remove the wire on the gen terminal and replace it with a jumper from the battery +.

The cut out is pretty simple, it just "smells" votage from the generator and closes the contacts, connecting the gen to the battery (via the ignition switch). The solid state does this with magic, and no moving parts (i did see a diode in there and what looked like a resistor)

FlatHeadSix
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#6

Post by FlatHeadSix » Wed May 23, 2007 7:38 pm

Sadist..
Actually, the cutout relay is always connected to the battery, you can prove it with a voltmeter. The "BAT" terminal should show full battery voltage, switch on or off. The feed from the relay to the switch is to light up the "GEN" light on the dash when you turn on the switch. There are 2 sets of contacts in the relay, when the engine is not running the feed to the idiot light is normally closed and the contacts which connect the generator to the battery are normally open, when the generator starts making electricity they reverse positions.

The "FIELD" terminal on the generator is for putting voltage into the 2nd field winding on the 32E when you turn on the lights, it takes power to make power. You can prove this with a voltmeter too, with the switch off or turned to the 1st position (ignition only) there should be zero volts at the generator field terminal, switch on the lights and you should get something close to battery voltage.

When you hook up the amp guage for your dial in you can also see how this works by "tricking" the old 32E. This was an old trick we used to use to get a little higher rate of charge while riding: set the headlight dimmer switch half-way between high and low beam, it should stay there if you get it sort of "balanced", this will cause the 35 watt headlight to turn off so that the only lights drawing power are the taillight and any other small lights you may have connected. Turn the switch to the 2nd click, start the engine and record the amps with the headlight "tricked" into off. With the engine still running, flick the dimmer to high or low so the headlight comes back on, the amps will drop. Now switch it to the ignition only position and see what happens.

Those charging systems were designed for use back before "the man" made us run with the headlights on all the time. The ideal output setting that you should be shooting for when adjusting the 3rd brush is the low charge rate the factory set for running all day in the ignition only switch position; somewhere around 1 amp.

Guest

#7

Post by Guest » Wed May 23, 2007 10:11 pm

Ah yes, the old tricking the 32E trick...
Thanks for the help guys...

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