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Old 19-06-2013, 16:41   #1
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Alternator putting out 100amps at 1400RPM

We just had our alternator serviced. Now it is putting out too many amps while it is supposed to only put out 64AMPS it is throwing more than a 100amps. What could be wrong?
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Old 19-06-2013, 16:55   #2
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Re: Alternator putting out 100amps at 1400RPM

My new one did something like that. Apparently when both alternators were linked through the batteries the batteries were sending mixed signals to the controller. So if the starter battery was connected only to the small alternator and the house bank only to the big alternator all was OK.
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Old 19-06-2013, 16:57   #3
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Re: Alternator putting out 100amps at 1400RPM

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Originally Posted by VVD View Post
We just had our alternator serviced.
Serviced? Was it rebuilt?
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Old 19-06-2013, 17:02   #4
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Re: Alternator putting out 100amps at 1400RPM

Yes it was rebuilt
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Old 19-06-2013, 18:12   #5
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Re: Alternator putting out 100amps at 1400RPM

If this is an externally regulated alternator, then the wiring from the alternator to the regulator is screwed up and is sending full unregulated field current to the alternator.

If it is an internally regulated alternator then something electrically was screwed up in the rebuilding.

Either way, your alternator will burn up soon if this isn't fixed.

David
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Old 20-06-2013, 13:21   #6
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Re: Alternator putting out 100amps at 1400RPM

There are several possibilities.

Assuming that your measurements are correct, i.e., your "rebuilt" 60 amp alternator is really putting out 100 amps @ 1,400 engine RPM, then....

1. during the rebuild, either the rotor was rewound with more turns than the original, OR another rotor with more windings was substituted;

2. the alternator is somehow getting full-field current, without regulation;

3. the alternator has an internal regulator which is connected and is not operating properly;

4. the external regulator (MC-612) isn't connected properly or isn't working properly.

These last three are unlikely in and of themselves to explain a jump from 60A output to 100A output, but could be part of the problem -- together with the rotor-with-more-windings possibility.

Bill
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Old 25-06-2013, 23:16   #7
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Re: Alternator putting out 100amps at 1400RPM

they probably rewond it better / bigger.

even with full field a 64amp alternator can't put out more then 64 amps... that is a max rating. (which was tested and will only been seen at full field)
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Old 25-06-2013, 23:24   #8
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Re: Alternator putting out 100amps at 1400RPM

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Originally Posted by djmarchand View Post
If this is an externally regulated alternator, then the wiring from the alternator to the regulator is screwed up and is sending full unregulated field current to the alternator.

If it is an internally regulated alternator then something electrically was screwed up in the rebuilding.

Either way, your alternator will burn up soon if this isn't fixed.

David

David has the answer.
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