"Rob" wrote in message
om...
Hi,

I have a 3000 rpm 11.8 KVA Fisher Panda generator that has both 1 and
3 phase outputs. I am looking to use the 3 phase output to power a 3
phase motor of around 10kW to drive a bow thruster in a barge at
approx 1500rpm. A colleagu has a Northern Lights 10KVA genset and
successfully powers a 9kW 3 phase motor in a similar set up. Would
appreciate any pointers - such as need for a capcitor bank to meet the
surge on starting.


It would be 'problematical'. A cap bank won't really help with starting of
AC motor.

I *have* seen a 2400 hp electric motor started on a 3000 hp diesel-gen set.
Engine running at about 60.5 hz, closed in the breaker. Engine dogged down
like anything and the motor started turning. The two met about 40 hz and
the governor of the engine was full open. Then both came up to full speed
and things ran fine from there. Had special overcurrent trips that were
blocked for 5 seconds right after shutting breaker. Quite a sight to
see/hear.

Starting such a large motor on a generator that is closely rated, well, it
may work, it may not. The voltage and frequency dip will be substantial.
But if its just dedicated to that one load, hey it may work. It would be
*nice* if you could start the load unloaded, but I don't know how you could
'unload' a bow thruster.

Since it will take longer than usual to come up to speed if the engine is
only just big enough, you may have to look at the overload protection. And
you will definitely want to limit the number of starts you do in a given
time frame. Obviously, being a bow thruster you may have to start/stop it
more than you would like, just to keep the barge from going where it
shouldn't.

You don't mention the type of thruster, but I guess it would be water-cooled
so probably not much problem there. The genny may need some extra cooling
if you plan on lots of start/stops.

And obviously you will want an engine that's well tuned and not going to
stall/sputter when you hit it with the load. My boating experiences on the
GLakes has taught me when you need maneuvering power, you *need* maneuvering
power. Not the time to have to nurse a sickly engine.

daestrom