Alternator keeps cooking itself

[Agvg]

The alternator is always connected, when starting the rpm are so low that there are no charge, and almost all alternators are self regulating when it comes to current so that's not a problem anyway.

 

[Agvg]

I don't see why no battery would fry the alternator. No reason at all. And if they persist, ask them to explain that. I bet they can't

My first question is where is the voltage regulator? Internal to the Alternator? An alternator will produce varying DC level depending on RPM, so you need a Voltage regulator.

It is usually the Diodes that will cause slight leakage, or some call it a rectifier.

The battery works as a buffer/load and helps the regulator to keep voltage with in specifications, without battery you can get very high voltage spikes and that can fry diodes in the rectifier.

 

[Industrial Toys]

Sorry, "BUFFER" is not an electronic term. Neither is SURGE, a term that is always thrown around. I have worked with, designed and build many voltage regulator circuits. Never got spikes on the output. A small cheap capacitor is usually added to the output and input and often several at different values, to stabilize voltage fluctuations and remove transients and noise. Can't see that anyone would build a voltage regulator that relies solely on the capacitance of the battery. Which still would not address the transients. An automotive or tractor electrical environment is very hostile for electronics and any such circuits must be built with this in mind.

 

[jwstewar]

I just went through this last year with my New Holland. I burnt the OEM up, a cheap Chinese replacement, and almost another local replacement before I figured out the caused. In my case it was the charge wire going from the alternator to the battery. It had a quick connect up under the dash area. This quick connect had gotten hot and melted and making intermittent contact. It would make contact, alternator would start charging and then it would lose contact. It would burn the diodes out of the alternator. I had to cut the quick connect out of the wires and just wired the two parts together and soldered. No issues since. Took some digging to find that one. Incidentally, to guarantee I never have another alternator problem, I had the shop rebuild my OEM alternator and I have it sitting on the shelf

 

[Agvg]

Sorry, "BUFFER" is not an electronic term. Neither is SURGE, a term that is always thrown around. I have worked with, designed and build many voltage regulator circuits. Never got spikes on the output. A small cheap capacitor is usually added to the output and input and often several at different values, to stabilize voltage fluctuations and remove transients and noise. Can't see that anyone would build a voltage regulator that relies solely on the capacitance of the battery. Which still would not address the transients. An automotive or tractor electrical environment is very hostile for electronics and any such circuits must be built with this in mind.

But you are talking about voltage regulators with input and output in a traditional way I suppose? Not a voltage regulator that control's a 3 phase generators output by regulating the field in the rotor?

 

[WranglerX]

Your electric shop may be taking your money because you have it and they don't. They may know little more than you about the electrical system and be shining you on experimenting as they go. Either way you lose. From your tale it sounds as though they have not seen the tractor - this is all hit or miss as you bring them parts. Your description of the way the system is wired sounds as though the alternator is always connected to the battery. If that's the case it is probably trying to work with the battery and maintain current as you have the starter engaged. I think in a normal system when the starter is engaged everything else electrical is disconnected, though I could be mistaken. If the alternator is trying to "help" the battery, it is looking effectively at a short circuit for a brief period of time. This could cook the alternator in short order. You will probably continue to experience electrical problems until you get the wiring sorted out. It will probably be a lot less expensive than continuing to buy parts as you destroy them. Or you could disconnect the alternator and put the battery on a charger when not using the tractor.

Typically a 1 wire alternator is direct connect to battery and has internal isolation (diodes) from battery ....... If there is regulator between alternator (multi wires) and battery, regulator should protect alternator (isolate) from battery. ..

Alternator generally do not producer any voltage until they get a short charge of 12 volts through "ALT" lamp in instrument panel to initiate the charge sequence...Seriously double the theory the alternator is trying to produce voltage to help battery to start tractor, as at this point alternator is not energizes or spinning fast enough to produce any voltage/amperage...

Generally the diodes in alternator protect alternator from drawing excessive voltage/current from battery, only way a alternator can "drain" a battery is to have defective diodes or bad regulation circuit...

If "shop" has not correctly repaired alternator after several trips to shop, go some where else, they are no qualified to to fix the alternator....

Also some system have a fuse in alternator out put. if a fuse is there and blown, it may be cause of all your problems....

Not sure if below statement it absolute, but various reads on different web pages tend to support this theory...

Don't Disconnect the Battery with the Engine Running

Dale

 

[Industrial Toys]

Firstly, I realized my "Bad" suddenly when making lunch. Obviously there are all kinds of "BUFFER" circuits in electronic logic.

No, not talking about generator VRs. Electronic VRs in general. MOST suggestions regarding electrical stuff on here are at least somewhat false it seems. Sometimes, the real fault or reason is never realized but it's just an assumption.

One reason not to disconnect a battery when running is because the leads could short! Again, such articles are so vague, without specifics, to be a joke.

 

[Agvg]

But there no point to do anything before the wiring between B+ on the generator and battery is 100% in working order, do also check B- so you are sure it's grounded properly.

 

[Industrial Toys]

If it was me. I would put a cheap appropriately rated fuse on the alternator output. HATE mechanics, electrical fixes or anything not OEM. 9/10s of the time, there was no reason to abandon the OEM wires and run new clothes lines around the engine compartment. Just because YOU couldn't figure out what was going on.