Butch Davis wrote:

Jor,

It is almost certainly a 3 phase generator. As I said before, the advantage
of a 3 phase generator is the ability to balance the load among the three
phases. If all the load is on a single phase the generator will be
operating in an unbalanced condition.

Recommend you talk to a local electrician to get a better picture of how the
generator is designed to operate.

Good luck.

Butch

Butch
"U" wrote in message
. ..

On Friday 25 November 2005 21:00, Terry Spragg wrote:


U wrote:


I 'inherited' a 3phase 15KW generator without documentation or even a

brand

name on it.


Why do you say it is 3 phase, if you don't have documents?
Generators with 3 hot phase outputs often include delta or Y
selection switches.

3 wire output, including neutral, plus ground, could be a 2 hot
phase system, with a 4 wire connector output.

If it is 2 phase (that's 2 hot phases plus neutral), then the
switching makes sense to me. Otherwise, I would be very sceptical.

The switches control which wires on the output are connected to
output, and which wire is neutral, (itself a hot connector for 110 v
output.)

I wouldn't go so far as switching while the test toaster is plugged
in, unless I was wearing rubber boots.

Terry K


Terry,

The generator is built into a boat I recently purchased. Frankly the only
reason I am saying it's 3-phase is because the previous owner told me so
and because I know I can get (at least?) two different output voltages at
the same time. If 2-phase is normal for a generator (I have no idea) then
it could also be 2 phase I suppose.
But, is there any advantage being able to choose which wires are connected
to the output and which one is neutral? As opposed to the generator simply
being wired correctly once and for all in the factory?

Thanks,

Jor






See above balancing the load output.

3 phase (5 wires!) might be an advantage if you had about a 20 hp
bow thruster, but I don't know of any other good reason to put 3
phases into a pleasure boat.

2 phase (4 wires) advantage is 220 v output. If you wanted to make
it flexible to work with diverse configurations of nationally wired
appliances it might seem reasonable to have flexible outputs to suit
hard wired outlets, but not to me. I'd wire it and seal it.

I wouldn't think that being able to select which L to make neutral
and ground to earth would be the sort of thing you'd want to
casually switch around with. Once wired in and set up, I'd be
inclined to remove the knob and hang it nearby with a list of
precautions in the bag.

Two odd appliances and the wrong L selected for neutral could set up
the chassis to 220 v differential, it seems possible. Then, some
genius could have decided it was better to remove the safety wire to
stop popping circuits. I know it sounds odd, but if you had seen
some of the things I've seen, you'd understand my trepidation.

Amateurs do amazing things.

Maybe it's a military quality thing that was put in the boat cause
it was relatively cheap surplus?

I wouldn't dare offer advice here without actually grokking the
scam, man.

You better get a pro in on it, and pay up your insurance before he
comes aboard.


Terry K