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Peter Hendra Peter Hendra is offline
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First recorded activity by BoatBanter: Dec 2006
Posts: 227
Default Amps draw per horsepower

On Thu, 08 Mar 2007 22:50:27 -0500, Jack Erbes
wrote:

Peter Hendra wrote:
Hi,
All this talk about circuit breakers has reminded me of something I
have been meaning to do.

I have a 1.5 horsepower 12 volt electric motor that powers my anchor
winch by a worm wheel.

Can anyone advise what the current draw is likely to be under load or
is this not enough information?


1 HP = 746 Watts,
1.5 HP = 1119 Watts,
1119 Watts / 12 V = 93.25 Amps

If it has a fuse on it, I wouldn't be surprised if it were quite a bit
more (150A?) to allow for the starting load.

This is all theoretical, of course. Is there a fuse on it?

Jack


Hi Jack,
Thanks for this.
No, I'm stupid. There is no fuse. I never knew what size to put on it
and it was one of those things I always was going to do.
This has cost me. Last year when I soloed the Atlantic as my wife and
son were back in Australia for his schooling, I installed a switch
from the cockpit in addition to the foredeck up and down foot
switches. I also installed a relay at the winch end for the cockpit
switch. As I couldn't see the lay of the chain when hauling up I made
a "wanderlead" from switches and a cable I had on board at Arricefe in
the Canaries as I couldn't buy anything else locally. Worked well
except I neglected to turn the up switch off once and consequently
burnt out the windings. I now have waterproof push switches that will
prevent this.

All I know is that the winch is 1.5 HP from the brochure. It has been
a great winch for over 14 years requiring only a new set of brushes.
Made by Sindico in New Zealand - all bronze, it was half the price of
a Maxwell. It sold so well that Maxwell bought them out and shut them
down. Thus, I cannot get any information.

At the moment I am in the yard in Trinidad getting ready for the
Pacific. I bought a chain counter in Sydney and have to go through the
fun of drilling two holes in the bronze for the magnet and sensor.

The winch is powered by a Chinese starter motor - at least that is
what it looks like. Three connections, one for positive and two for
negative up and down. would 150 AMP be OK?

cheers and thanks
Peter
N.Z . yacht Herodotus