alternator question!
01-02-2012, 07:46 PM
#1
Staging Lane
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alternator question! the alternator in my car is going out. when running I have only about 13 volts at the most...
I have a duramax alternator I'm thinking about putting in it being that its 145 amp but my question is....
am I gonna destroy it by turning 6k in my car? duramax red line around 4k at the most.
any help is greatly appreciated!
I have a duramax alternator I'm thinking about putting in it being that its 145 amp but my question is....
am I gonna destroy it by turning 6k in my car? duramax red line around 4k at the most.
any help is greatly appreciated!
01-02-2012, 08:36 PM
#5
Where did you get your information from?
Most normal alternators need 2000-2500 rpms to just be able to output power; this is alternator rpm's not engine rpms, and is why the alternator pulley is smaller than the engine crankshaft pulley- so the alternator spins faster. Alternators need around 6000 rpm generally to produce adequate power. As to their maximum rpm that's well over 10000 rpm more like 15000 rpm, and I believe it's more of a physical limitation not electrical. The voltage regulator controls how much power, or current, the alternator produces so high rpm does not mean the alternator will produce too much power and overheat, it does not work that way. What would happen with high rpm is centrifugal force and the internal spinning mass of the alternator and the weakness of the casing would make it let go, and this would be worse for larger heavier alternators.
Also, don't believe maximum rated power for alternators, that duralast "marketed" at 145 amp cannot produce a continuous 145 amps of current at 14 volts, it would overheat and fail. The same goes for any auto alternator, generally expect them to be good for 1/2 to 2/3 rated power continuous which would happen around 6000 alternator rpms and higher.
Most normal alternators need 2000-2500 rpms to just be able to output power; this is alternator rpm's not engine rpms, and is why the alternator pulley is smaller than the engine crankshaft pulley- so the alternator spins faster. Alternators need around 6000 rpm generally to produce adequate power. As to their maximum rpm that's well over 10000 rpm more like 15000 rpm, and I believe it's more of a physical limitation not electrical. The voltage regulator controls how much power, or current, the alternator produces so high rpm does not mean the alternator will produce too much power and overheat, it does not work that way. What would happen with high rpm is centrifugal force and the internal spinning mass of the alternator and the weakness of the casing would make it let go, and this would be worse for larger heavier alternators.
Also, don't believe maximum rated power for alternators, that duralast "marketed" at 145 amp cannot produce a continuous 145 amps of current at 14 volts, it would overheat and fail. The same goes for any auto alternator, generally expect them to be good for 1/2 to 2/3 rated power continuous which would happen around 6000 alternator rpms and higher.
01-02-2012, 11:56 PM
#6
Staging Lane
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the alternator I'm thinking about putting in my car is from a 2003 chevrolet silverado 2500hd duramax diesel. I cant find anything on part numbers on any alternator but it is ac delco part. thanks for the good info by the way!
