Alternator temperature....

[lateral]

Looking for a consensus on what maximum temp setting for alarm on
engine driven alternator?
I guess this would depend on alternator manufacturer but I am curious to other peoples experiences, especially a fried alt with temp control.

[GordMay]

Balmar’s alternator output chart is based on two temperature levels - (ambient 26oC) and (hot 90oC).

Their Alternator Temperature Sensor (MC-TS-A) adjusts voltage to help initiate efficient charging when the alternator is above the optimal working temperature (109° C - 229° F)

[a64pilot]

Alarm?
I've heard of Alt's operating at 300F with no problem, but I'd set the alarm about there.
My belief is although they have done it for awhile and no demonstrated harm, effects may be cumulative and I don't want to shorten life. How hot can grease get and not oxidize and eventually not lubricate? Depends on the grease I'm sure and that may not be the most temp sensitive thing, maybe it's the insulation? Plus where are you measuring the temp will I am sure be very important as I bet some spots of an Alt run very hot and some spots much cooler?
Maybe an IR thermometer to find the hot spot?
When viewed straight on, the hot spot on my alt seems to be the port side of the alt, the Starboard side of the boat, the side closest to the engine, is that common?, I have no idea.
Just a data sample of one.

I do know that temp is THE limiting factor on my 125 amp, I can't get near that amount of power, due to heat build up. Most I seem to be able to pull continously is about 80, maybe 90.
Gut feeling is if I could speed it up a lot, I'd get much more power and cooling.

[SV THIRD DAY]

Mark Grasser, the owner/fabricator of DC Power Solutions alternators says that several external regulators on the market have a temp cut-off/alarm at 190-degs F, which in his view is pretty conservative. Mark said that he is comfortable with his alternators running at 225-degs F.

[ColdEH]

My Echo-Tech alternator runs at 190 degrees thats it . In the long run, heat kills so I'm OK with a little less amps and less heat.

Regards

[Sailmonkey]

Last time I had the batteries discharged enough to stress the alternator it popped up to about 220-230 by the infrared thermometer and stayed there. It's a small case balmar and the output current dropped to 70 from the max of 80. I would de-rate the thing but it doesn't run like that very often. I've not had any ill effects from this (yet).

[lateral]

Great! Just the info I needed. Thanks guys.