Colin,

It would be neat if you gave us any idea what this is about:
What engine,
What alernator
anything else that might interesting.

Are you so far from the engine that you could not hear it?

Matt Colie

CS wrote:
My engine panel overspeed alarm is driven by the freq output from the
alternator from the AC taps. The overspeed alarm goes off when the
alternator speed is 5000rpm, equiv to engine speed 2300rpm. With a new
alternator, I've reduced the pulley size considerably and the alt speed
is 5000 rpm at 1400 engine rpm - and the alarm now goes off.
The engine panel has a pot to adjust the overspped freq but looking at
the service bulletin the freq will be outside its adjsutment range
I've got 2 options - the easy one - disconnect the wire - is an
overspeed really necessary or useful??
Try and get a device to divide the frequency.

Grateful for any ideas.

Engine is a Daewoo L136 and the original alternator, 50A 5000 rpm max
continuous, was replaced by a Leece Neville unit, 110A 8000 rpm max
cont . To get more amps from the alternator, I reduced the pulley so
8000 alt rpm is now achieved at just over 2300 engine rpm - engien
normal max is 2200 rpm. The engine is beneath my feet in a luxemotor
barge - so I think the oversped is somewhat superfluous.

Colin,

Don't sweat the overspeed.

Unfortunately, this engine is too new for my catalogues, but I and quite
sure that it is using a Hitachi copy of a Bosch TE injection pump. This
pump includes a controlling governor that not only controls the engine
to produce the ordered crankshaft speed but also limits the speed to a
safe maximum. The only way to exceed that speed is by introducing
additional fuel (often that is injested lube oil) and it that occurs
there is often little the operator can do without getting too close to
the engine.

I was glad to see that you are running double belts because that is just
about and maybe a little bit over the capability of a single belt.

Matt Colie
Lifelong Waterman, Licensed Mariner (Diesel Chief...)



CS wrote:
Engine is a Daewoo L136 and the original alternator, 50A 5000 rpm max
continuous, was replaced by a Leece Neville unit, 110A 8000 rpm max
cont . To get more amps from the alternator, I reduced the pulley so
8000 alt rpm is now achieved at just over 2300 engine rpm - engien
normal max is 2200 rpm. The engine is beneath my feet in a luxemotor
barge - so I think the oversped is somewhat superfluous.