Removing an internal regulator from alternator ???

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Morrie

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Jun 3, 2004
86
Hunter 37-cutter Hilo, Hawaii
I want to install a xantrex exrernal three stage regulator to make sure my nice new 500 amphour battery bank is charged as effective/efficient as possible. I now have an 80 amp alternator with an internal regulator and I don't want to buy a new high amp alternator till next year. Does anyone know if it is possible to disconnect or remove the internal regulator? Thanks
 
Jun 16, 2005
476
- - long beach, CA
ALTERNATE REG.

You can do it yourself, but you can also take it to a shop where, at the same time, they can remove the regulator AND rebuild it to put out 115 or 120 amps, because alternators don't put out their rated capacity. A higher capacity will give you a higher output, even if it's not the max. Don't forget, you have to have an external regulator, too.
 
Dec 2, 2003
4,245
- - Seabeck WA
Yep, have them stuff the biggest stator available

in it. That's the only difference in alternator output. Or do it yourself. But if you've never opened one of these ask the shop to show you how. Tell them you are an offshore sailor and need to know. A tip (cash to them)would be in order. The 'trick' is putting it back together. These are so much fun.
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
Hmmm....

If you "rebuild" an alternator from 80 Amps to higher Amps, don't you really have a new alternator? For relatively little money you can get a new, high output alternator set up for external regualtion, less than $400 from Hamilton Ferris. You can have your alternator converted very cheaply to external regualtion at an alternator shop, who can test it at the same time. You will also have to make sure that your external regulator can limit the field current so that you don't exceed the alternator output rating, which could happen with so much battery connected. Mine can dump 100 amps initially into a bank of 2 24D 75 AH wet cells batteries.
 
Dec 2, 2003
4,245
- - Seabeck WA
Hmmm,,,, Na,

The field voltage can not exceed the alternators capacity. That is, unless you can provide greater voltage than your bank has, such as 24 volts to a 12 volt alternator. But I've never heard of such a thing, just thought it up. :) Weird, but I do that. And just because the alternator can put out a lot of power doesn't mean it will survive to a ripe old age. Several factors come into play. Not the least of which is the dreaded rectifier melt down. And on Yanmars, most are limited by the single drive belt, damn it.
 

Morrie

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Jun 3, 2004
86
Hunter 37-cutter Hilo, Hawaii
Thanks

Thanks for the answers. There's an alternator shop just a few blocks from my marina. I thought of asking them the same question I ask you guys, but I didn't want to go down there and asked them to do something that was totally impossible.
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
to Fred

I don't understand your comment. One can certainly provide enough field current so that the alternator's rating is exceeded. Oen can think of it as if ALL alternators are 100 Amp alternators, it's only a question as to how long they are. A lower-reated alternator will fail for thermal reasons. The regulator doesn't know the alternator rating or the battery bank impedance, it only regulates the field current according to the sense voltage. So, with a large enough battery bank,and therefore low impedance, the regualtor could supply enough field current so that the alternator puts out more current than it is rated for.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
JVISS

DC circuits do not have impedeance. That is an AC circuit thing. DC circuits have resistance.
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
Correct, ...

... you are Bill, please pardon my lapse. Just used to thinking of resistance, i.e., "DC resistance," as a subset of impedance; more precisely, just the real part. In fact, though, there aren't any DC circuits, only DC analysis of circuits. You will find all of these components have reactance, it's just not an important factor for low speed, i.e., steady state DC analysis of these circuits. The point of my post remains valid. An alternator, regardless of it's rating, will put out as much current as necessary to bring the battery bank up to the regulated voltage, assuming a couple of things like big enough charging wire, and that the system stays in regulation. So, it's important to size the alternator to the bank to be charged (or vice versa).
 
Jun 2, 2004
24
Catalina 36 Port Clinton, OH
Simple on Motorola

I recently converted my Motorola 90 amp alternator to external regulation by first taking it to a local Leese Neville dealer whoe did the conversion for $30. Simple conversion after they ordered the conversion kit. I installed a BALMAR ARS 4 external regulator bought on E-Bay for $125 and every thing works fine.No changes are required with the windings.
 
Dec 2, 2003
4,245
- - Seabeck WA
JVISS

An alternators MAXIMUM capacity output is achieved by the STATOR, not any arbitrary rating. The regulator will send voltage to the 'field' to create output. That output is sensed as voltage. If the voltage is not too high for the value in the regulator, it will continue to be applied until the batteries report that they are getting full or the alternator system fails from too much output. The bigger the stator the more heat potential that must be dealt with by the alternator. That's why 3 stage regulators have temp sensors. Then add to that heat an environment such as many engine boxes provide; Heat and lots of it, then most alternators with high output are in trouble. Two years ago, when I was making emergency repairs in Canada because of a melted rectifier, the local repairman said that 3 stage regulators are what keeps him in business. That's why I built that box and removed the rectifier from the alternator case and changed to a lage frame version without solder and thusly removed it from engine room heat. Works great. Again, a regulator can't make an alternator put out more than its' capacity. That's illogical.
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
Fred

Fred, You apparently are not reading my note carefully, and you are reading things into it that I have not stated. 1. I didn't say that the output was a function of the rating. 2. It's field current, not voltage, that controls output. 3. The regulator senses load voltage and controls field current to keep the load voltage in regulation. I think this is what you are saying, too. 4. I didn't say that a regulator can make an alternator output more than it's capacity, I said it can output more than its rating. The result is usually thermally induced failure. Ultimately you can bump into the maximum output capacity of an alternator, but you are more likely to find the "end" of an alternator by exceeding it's thermal limit. Larger capacity alternators have heavier windings, etc., than lighter ones. As a side note, I've been charging a house bank with a 125 Amp alternator and external regulator for five years of cruising so far, and I've never burnt out anything (yet).
 
Dec 2, 2003
4,245
- - Seabeck WA
JVISS, Point #4 is what's causing this exchange.

My position is that an alternator rating is applied by the manufacturer. (OEM) That rating is often just a guess. And it can be referring to any position on the alternators output graph, temperature compensated or not. My point is that 'ratings' are meaningless. If a bank wants juice and the regulator sees low enough voltage, it'll ramp up the alternator to it's full output. It doesn't matter what the 'rating' is. If the alternator design can't handle it, it'll die. It's a small point, true, and in the meaning of life, who cares? :)
 

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
Yes.

Fred, that's exactly what I have been saying. The maximum output capacity can be achieved during conditions that exceed the alternator's rating, and it may indeed fail, by melting, or whatever. So we agree.
 
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