"Richard Casady" wrote:

The copper and iron
take time to heat up which is why you can get away with stuff for a
while.

This is a trick some alternator manufacturers play.

The rating they publish is a "cold" rating which is cheating.

The true rating of an alternator is a "hot" rating.

Try runing an alternator under full load in the Arizona desert in the
summer time if you truly want a test.

Starter motors put out about ten times what their size indicates
they
should and can easily be burnt up if you have a good battery.

Yep, cranking motors are definitely time rated; however there are
exceptions.

When I worked for Leece-Neville, a standard cranking motor test was to
lock the roter of a cranking motor ia a vice, then connect two (2),
fully charged 8D batteries in parallel along with a 600A knife switch,
some 4/0 welding cable and an 8 ft long wooden 2x4.

Secure the switch to the wooden floor, and wire everything up.

One guy stands by with a fire extinguisher, another with the 2x4.

Use the 2x4 to slam the knife switch shut and stsnd back.

The cables would smoke and snake around, leaving burn marks on the
wooden floor, the cranking motor grunts and gets hot until the
batteries are discharged.

When discharged, beat the switch open and wait for things to cool
down.

Next day check out the cranking motor and try to start it.

If it would turn over, it passed.

(You don't run that test very often)

How can an alternator eat belts if the manufacturer
picks the belt size.

I used to do belt and sheave design applications for heavy duty
alternators.

You start with the torque/RPM curve which dictates the required load
the belt/s must handle.

The belt/s chosen dictates the minimum sheave size for the alternator
and minimum angle of wrap.

Given this information, the final design of the drive is the
responsibility of the engine manufacturer.

The big boys have no problem with dual belt drives.

The people in the consumer market are another story.

Lew