Starting issues - Batteries or charging

DrivingMissLazy · December 30, 2006, 05:04:40 PM

Sammy, is it possible that positive ground systems, like the 4104, would use the positive field regulator and the negative ground systems use the negative field regulators?
Richard

Sammy · December 30, 2006, 07:23:16 PM

Hello Richard, I do not know the answer to your question. I not familiar with the 4104 coach or positive ground systems. The buses were all negative ground systems. There were 2 different voltage regulators that were used, depends on how the field coil was controlled - that determined which regulator was used. Hope this may help.
Regards,
Sammy

DrivingMissLazy · December 30, 2006, 09:08:07 PM

Thanks, that was what I was wanting to know. BTW, the 4104 was a positive ground system.
Richard

gus · December 30, 2006, 09:27:14 PM

Richad and Stan,

Sorry, I thought this string had died and hadn't looked at if in a while.

First-I assumed we were talking about automotive alternators since he was talking about charging his batteries. AC alternators are an entirely different animal. As one poster said, all generators are alternators until something is done to the AC output.

An automotive gen DC output is a clipped AC to make it look like DC, good enough for auto use, and it has permanent field magnets. By placing the brushes in the right place only a few armature windings are used at a time to keep the output polarity positive.

An automotive alt DC output is rectified AC and it has no permanent magnets. Diodes are used to keep the output positive. All the stator windings are used all the time so it is much more efficient. I guess they are called alternators because the are constructed pretty much the reverse of auto generators? The stator in an alt is the armature. In a gen it is the field.

You don't flash the field in an alt because it has no permanent magnets so flashing would do no good and you run the risk of accidentally flashing the diodes in the wrong direction thus destroying them!

I'm assuming that giant AC generators have giant permanent field magnets and need flashing but since it is AC it doesn't matter which way it is flashed.

The DC auto gen direction matters because it has the brushes placed to make the DC output a certain polarity.

An auto gen will provide output even if no battery is present.

An alternator will not provide output without some field excitement by an outside source, normally the battery. However, if the battery is completely dead (0 volts) there will be no output.

Running an auto alt without a load connected will destroy it.

This is all pretty much what Jerry said but you asked. No urban legend here, ask any auto mechanic.

Chaz · March 29, 2007, 03:51:23 PM

Hey Guys,
I still have that charging issue. A mechanic buddy of mine did some checking on it and found that there wasn't any voltage going to the regulator to control the output voltage of the generator.
---- Does that make sense??-----
Anyway, I need to run it (to St.Louis) and I am going to do what he said, for now, to get me thru: I ran a #8 wire from the battery post (big post) on the generator to the POS post on the regulator with a high amperage switch between them. He says just remember to turn the switch off when I park.
Doing that shows the generator charging using a VOM.

Now, IF any of you think that is a BAD thing to do and will hurt something, PLEEEEEESE give me a call on my cell as I am just about out the door. (812) 212- 2222

Thanx a bunch!!!!!!!!!

Heading west, young man,
Chaz

Lee Bradley · March 29, 2007, 04:36:14 PM

Chaz,
Sounds like your low-voltage cutout relay in the regulatory has failed; you may not be getting current to the batteries even though the generator is showing voltage.

I would make sure the switch you installed is off until the engine is running and off before the engine is stopped. Your generator will act as an electric motor when connected to the battery and your wiring is not up to that load.

Sammy · March 29, 2007, 06:05:36 PM

Chaz, your buddy is correct, do not worry.
The voltage regulator cannot control the charging system without battery voltage at the POS or BAT terminal of the regulator. Send e-mail if you need any help or have any questions.
Sammy

gus · March 31, 2007, 03:01:56 PM

Chaz,

It sounds to me as if that wire detached is the voltage sensor wire so it needs to be connected only when the engine is running or it will slowly discharge the battery.

I have converted a couple of antique tractors to alternators and they all have this switch except one that already had a light. When an alternator is mounted on a gasoline engine it the engine won't shut off unless the switch is opened because there is a small amount of feedback to the ignition system through the alternator!

You can substitute a small light or resistor for the switch and get the same results. This is the same wire that operates the (Idiot light) on autos. I can't tell you the size of the resistor but it is pretty small, this is not the charging circuit.

This is a very low amp circuit so your #8 wire is way overkill. A 22 gage wire would probably work just fine.

Stan · March 31, 2007, 05:31:00 PM

The DN 50 alternator draws a maximum of about 9 amps on the field plus a little loss in the regulator so your #8 is fine until you get around to fixing the problem.

Chaz · April 03, 2007, 09:42:12 AM

Thanx guys!!
I made it out and back ok. I love my bus!!!!!!!! But on the way back, the lights were... uh, pulsating for lack of a better term. They would dim a little and then brighten back up. I'm not sure if that was because of my regulator thing or not. They didn't do that on the way out.
Looks like I'm going to have something else to do now.
Thanx again!!
Chaz

Ace · April 03, 2007, 09:58:21 AM

I have 4 batteries in mine and I would like to know how you charge each 12v battery without disconnecting them since on some they are wired neg to positive and positive to negative? I have always charged them seperately but if there is an easier way, please inform!
Ace

DrivingMissLazy · April 03, 2007, 10:22:23 AM

Chaz, try turning on the headlights the next time this happens and see if it quits pulsing. Your batteries are probably fully charged and the regulator is just checking and making sure. This is apparently a problem with some of the older regualtors.

Quote from: Chaz on April 03, 2007, 09:42:12 AM
Thanx guys!!
I made it out and back ok. I love my bus!!!!!!!! But on the way back, the lights were... uh, pulsating for lack of a better term. They would dim a little and then brighten back up. I'm not sure if that was because of my regulator thing or not. They didn't do that on the way out.
Looks like I'm going to have something else to do now.
Thanx again!!
Chaz

Chaz · April 03, 2007, 11:04:13 AM

Sorry, my bad. The headlights were the lights that were pulsing.

Do you think what I did to get by is the cause?? I guess I will find out when I get it fixed, huh.

DrivingMissLazy · April 03, 2007, 12:25:33 PM

Chad I do not think you did anything to harm anything. This is a common complaint that I have seen dozens of times on various boards. As I recall the problem is generally the regualtor pulsing because there is not enough load on the alternator.
Richard

Quote from: Chaz on April 03, 2007, 11:04:13 AM
Sorry, my bad. The headlights were the lights that were pulsing.

Do you think what I did to get by is the cause?? I guess I will find out when I get it fixed, huh.

Chaz · April 03, 2007, 12:58:48 PM

Thanx Richard. I guess as problems go, that isn't such a bad one.

If I'm not mistaken, if I would have my 4024 invertor hooked up, the generator would be helping with other electrical needs. (?)

Thanx again,
Chaz