Looking at a 1200 watt Lofrans. 80 to 110 amps. 40' from batts to
windlass.
What size wire?
Thanks
Gordon

Big as your thumb!


"Gordon" wrote in message
...
Looking at a 1200 watt Lofrans. 80 to 110 amps. 40' from batts to
windlass.
What size wire?
Thanks
Gordon

On Nov 17, 9:11 am, Gordon wrote:
Looking at a 1200 watt Lofrans. 80 to 110 amps. 40' from batts to
windlass.
What size wire?
Thanks
Gordon

The manual for my Horizon 1500 says 2 AWG (25mm^2) is adequate for a
60' run.

-- Tom.

On Sat, 17 Nov 2007 11:11:26 -0800, Gordon wrote:

Looking at a 1200 watt Lofrans. 80 to 110 amps. 40' from batts to
windlass.
What size wire?
Thanks
Gordon

The electric utilities don't like to lose more than 10% of their power
in transmission lines. If you adopted the same policy, you would look
for a 1.2 volt drop or less in 40 ft times 2 (there n back)

You are therefore asking: what gage wire will have a resistance value
of R = E/I = 1.2 V / 100 A per 80 ft or
0.012 X 100/80 ohms per hundred ft. = 0.015 ohms/hundred ft.

I could look it up, but you could probably do this too.
It's somewhere between 1/0 and 2 AWG.

Regards


Brian W

On Sat, 17 Nov 2007 12:13:50 -0800 (PST), "
wrote:

On Nov 17, 9:11 am, Gordon wrote:
Looking at a 1200 watt Lofrans. 80 to 110 amps. 40' from batts to
windlass.
What size wire?
Thanks
Gordon

The manual for my Horizon 1500 says 2 AWG (25mm^2) is adequate for a
60' run.

-- Tom.

You have to calculate both sides of the circuit. 40' from the battery
to the winch and 40' from the winch back to the battery. A 80' run of
wire.

A quickie calculation based on guessing your operating practices shows
1 AWG however you should make your own calculations based on actual
operating procedures.
Bruce-in-Bangkok
(Note:remove underscores
from address for reply)

80 feet of #2 has a resistance of .012 ohms and so a drop of 1.2 volts
at 100 amps. #2 with typical insulation is rated at 95 amps. Maybe you
are "intermittent duty"?

80 feet of #1 has a resistance of .0096 ohms, and so a drop of .96
volts at 100 amps. #1 is rated at 110 amps.

I have the same 40' run- 80' round trip.

My Simpson Lawrence windlass can easily pull 100-150A. My Hunter
sailboat was factory wired with 2/0 gauge cable. The diameter of the
wire inside the insulation is about the size of a dime.

It's big, but the benefit is minimal voltage drop in the wire and thus
more power to the windlass motor.

Rich



On Sat, 17 Nov 2007 11:11:26 -0800, Gordon wrote:

Looking at a 1200 watt Lofrans. 80 to 110 amps. 40' from batts to
windlass.
What size wire?
Thanks
Gordon

On Nov 18, 2:03 am, Bruce in Bangkok wrote:
On Sat, 17 Nov 2007 12:13:50 -0800 (PST), "
The manual for my Horizon 1500 says 2 AWG (25mm^2) is adequate for a
60' run.

-- Tom.

You have to calculate both sides of the circuit. 40' from the battery
to the winch and 40' from the winch back to the battery. A 80' run of
wire. ...

Fair enough. For a 90' run the manual says 1 AWG and for a 120' run
it says 1/0.

-- Tom.

On Sun, 18 Nov 2007 11:21:06 -0800 (PST), "
wrote:

On Nov 18, 2:03 am, Bruce in Bangkok wrote:
On Sat, 17 Nov 2007 12:13:50 -0800 (PST), "
The manual for my Horizon 1500 says 2 AWG (25mm^2) is adequate for a
60' run.

-- Tom.

You have to calculate both sides of the circuit. 40' from the battery
to the winch and 40' from the winch back to the battery. A 80' run of
wire. ...

Fair enough. For a 90' run the manual says 1 AWG and for a 120' run
it says 1/0.

-- Tom.

Then do it.

A friend fiend bought a second hand cat and was complaining about how
gutless the windless was. I suggested he check the voltage at the
motor terminals with the windless under load. He did and found low
voltage. His decision was to install a separate battery solely for the
windless in the forward compartment, but regardless of the method you
need to have at least 12 volts at the motor terminals when the
windless is under load.


Bruce-in-Bangkok
(Note:remove underscores
from address for reply)