Windlass Cable Size, 2-AWG or 4-AWG

gearyg

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Aug 28, 2006
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Hello, I am installing a Lewmar 700H Pro Series Windlass on a 21' CC. My batteries are in the console, so the wire length will be approx 18' to 20'. I am planning to use ANCHOR tinned wire in the 4-AWG size. The installation guide recommends to use 8-AWG size, but West Marine recomends to use 2-AWG size.

Do I really need to go to a 2-AWG?...as a 4-AWG is already doubling the manufacturers recomendations...thanks.
 

JB

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Re: Windlass Cable Size, 2-AWG or 4-AWG

With that long run I would use #2, gg.

#4 would probably be okay if the batteries were close, but 18-21' is a long run.
 

PondTunes

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Re: Windlass Cable Size, 2-AWG or 4-AWG

With that long run I would use #2, gg.

#4 would probably be okay if the batteries were close, but 18-21' is a long run.

Agreed you're running a very long way and operating a high draw accessory you should use #2. Not saying #4 wouldn't work but it's in the gray zone imo.
 

wire2

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Re: Windlass Cable Size, 2-AWG or 4-AWG

What's the current stamped on the name plate?
 

wire2

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Re: Windlass Cable Size, 2-AWG or 4-AWG

Length of conductors is 40 ft (2 x 20 ft
Resistance per foot of #4 copper is .000292Ω
Resistance of 40 ft is .01168Ω
Current is 35 amps.

Voltage drop (E = IR)of #4 is .40 volts or 2.9%

Voltage drop of #2 is .3 volts or 2.1%

Voltage drop of #6 is .7 volts or 5%
In other words, with battery at 13.8v, windlass will receive 13.1v. No problemo.

Personally, I'd go with #6 as it's a very intermittent load.
Mercruiser trim pumps are also 35 amps, I believe they get only a #10 wire. At 5 ft + 5 ft it's a 5.7% drop.

West Marine is covering their butt. Extremely.
 
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gearyg

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Re: Windlass Cable Size, 2-AWG or 4-AWG

Thanks alot guys, lots of great information. Wire2, Lewmar also recomends going with AWG 6 for my application....impressive calculations BTW.
 

wire2

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Re: Windlass Cable Size, 2-AWG or 4-AWG

Thanks alot guys, lots of great information. Wire2, Lewmar also recomends going with AWG 6 for my application....impressive calculations BTW.
It comes easy for a licensed electrician.:D

You're welcome.
 
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