Wire Gauge Question

[TheOtherLine]

I am replacing the windlass on my boat.

The manual on the OLD windlass calls for 10g wire for runs up to 44 ft, then 8 gauge for any run longer than 44 ft.

The manual on the NEW windlass calls for 8 gauge up to 33 ft and 6 gauge from 40 to 53 ft, then 4 gauge for anything longer.

I understand that you have to measure the run from each connecting point ( the full run, both ways )

My question is, How critical is it to re wire if I am within a few feet of the guidelines? For example, If I currently have 8 gauge and the run is just a few feet longer (requiring 6 gauge), do I really need to re wire?

I am just trying to avoid a total rewire if I can.

Also, if I have to rewire and the manual calls for 6 gauge, can I just use 4? Any problems with that?

 

[evetsmd]

http://www.classicparker.com/phpBB2/viewtopic.php?t=350&highlight=wiresizer

Try this to see if you can best decide what you need. It was a nice find from Dale.

 

[TheOtherLine]

http://www.classicparker.com/phpBB2/viewtopic.php?t=350&highlight=wiresizer

Try this to see if you can best decide what you need. It was a nice find from Dale.

I've seen that link at it was a great post. Thanks for reminding me about it.

However, in this case, I already know (from the manual) that I need 6 gauge wire. I'm just trying to figure out if I can cheat and just how critical it is, if I do.

 

[evetsmd]

re wire if I am within a few feet of the guidelines

for a few feet, I don't imagine it should be a problem and if you use 4 gauge instead of 6 gauge, that's actually better, the 4 gauge is the heavier wire.

Maybe another consideration is how old is the wire that's already in place? What kind of condition is it in?

I'd go ahead and try it, when done you could measure the voltage at a few points and see where and how much lose across the wire that your getting.

If the voltage at the windlass is too low then the windlass under load will be drawing more current (not a good thing, more current is more heat).

Example is Power = voltage x current.......if the windlass needs say 150Watts of power to operate properly then:

150W/13.5Volts = 11.1 amps

for the same load of 150Watts if the voltage drops at the windlass to say 12 volts then

150W/12Volts = 12.5 amps

that's an extra 1.4 amp draw for the windlass to be able to do the same work at 150Watts.

The power company faces the same problem. Could you imagine the size of the wire if there line voltage on the poles was at 110Volts......so what do they do, they run much higher line voltages on the poles (lower current) and then step down to 220Volts thru a transformer when it gets to your house.

OK, I probably confused the heck out of you, sorry, as I suggested, you could give the old wiring a try and then measure the voltage at the windlass under load (use a good multimeter) you'll know real quick if its going to work or not!

 

[TheOtherLine]

evetsmd: Thanks for the tips. The condition of the wiring is good. It's only 2 years old.

I actually went out and checked out what was on there already and I measured the run again.

I lucked out! I think. The manual for the existing windlass install calls for 8 gauge wire for my run length.

Whoever installed the windlass (Parker? Dealer?) used 6 gauge.

The manual for the new windless, for my run length, calls for 6 gauge. I don't need 4 gauge until I exceed a 60 ft run. I have a 53 ft run and I'm not off by 7 ft.

What do y'all think? Should I rewire using 4 gauge?

 

[evetsmd]

Sounds like you meet the requirements of the new windlass with the 6 gauge wire that's already installed.

I'd use what you have! After you have it installed, I would still do a voltage measurement at the windlass with the windlass under load just so you can feel good knowing all is OK!

Good luck with the install......it will work just fine!

Steve -

 

[TheOtherLine]

I would still do a voltage measurement at the windlass with the windlass under load just so you can feel good knowing all is OK!

Steve -

Motor Power: 12V
Typical Power: 500W
Normal Current Draw: 35A
Circuit Breaker: 50A

Ok, so, if I understood you correctly, this thing should draw 35 amps at 12 volts? If I test it and I am reading 10 volts under load, then I've got a problem?

 

[DaleH]

We need to know 2 things before we can properly answer this question ...

1) What is the length of the actual wire run length from power source to windlass?


2) What is the recommended maximum voltage drop for such a device?

In any wire calculation, you would DOUBLE the 1-way wiring run length and use that 2X-number in the ampacity equation.

 

[evetsmd]

You got it......you have to assume the 500 Watts is a constant for the windlass to do it's job which I assume would be the worst case situation when it is breaking the anchor free from the bottom....it wants that power one way or the other.....

If you only have 10 Volts at the windlass, then for the windlass to get it's same 500 Watts, it needs 500 Watts/10 Volts = 50 amps....your also loosing 2 Volts in the wire which at 50 amps = 100 Watts of power heating up the wire.

Reality is you'll have lots of variables - assume the engine will be running when you pull the anchor (higher voltage, less current) - I don't believe the 35 Amps is a constant draw but could represent the max power available and needed to make the initial pull and break the anchor free. This should be the hardest work the windlass has to do so for that initial tug that's when it needs the most power (just like starting the engine).....when it's just reeling in anchor and rode it should need a lot less power (current drain) to do the job. So if you had a volt meter connected across the windlass what you might see is a dip in voltage during the initial breaking of the anchor free from the bottom then the voltage pop back up on just the reeling in process.....

If you have 6 gauge wire already in place and that's what the windlass company specifies for the length of wire your running, as I said earlier, I think your in good shape.

I would also encourage you to check every connection, good lug crimps, clean terminals.

Maybe we can get some additional input from some of the other guys who have been thru this before......

Good luck with the install......it will work just fine.

 

[TheOtherLine]

We need to know 2 things before we can properly answer this question ...

1) What is the length of the actual wire run length from power source to windlass?


2) What is the recommended maximum voltage drop for such a device?

In any wire calculation, you would DOUBLE the 1-way wiring run length and use that 2X-number in the ampacity equation.

Here's what the manual says:

2.1 Electric cable selection
To achieve the best performance and to safeguard your electrical
system it is essential that any electrical windlass be fi tted with
suffi ciently large diameter cable to cope with the current draw
imposed upon it and to keep the voltage drop within acceptable
limits. In any circumstance voltage drop due entirely to cable
resistance should not exceed 10%.

The following table gives recommended cable sizes. The
recommendations are based on total length of cable required,
from the battery, following the route of the cables.
• Total length of cable run is from the battery to the
windlass, and from the windlass back to the battery.

See pic

My cable run total is 53 feet.

 

[TheOtherLine]

You got it......you have to assume the 500 Watts is a constant for the windlass to do it's job which I assume would be the worst case situation when it is breaking the anchor free from the bottom....it wants that power one way or the other.....

If you only have 10 Volts at the windlass, then for the windlass to get it's same 500 Watts, it needs 500 Watts/10 Volts = 50 amps....your also loosing 2 Volts in the wire which at 50 amps = 100 Watts of power heating up the wire.

Reality is you'll have lots of variables - assume the engine will be running when you pull the anchor (higher voltage, less current) - I don't believe the 35 Amps is a constant draw but could represent the max power available and needed to make the initial pull and break the anchor free. This should be the hardest work the windlass has to do so for that initial tug that's when it needs the most power (just like starting the engine).....when it's just reeling in anchor and rode it should need a lot less power (current drain) to do the job. So if you had a volt meter connected across the windlass what you might see is a dip in voltage during the initial breaking of the anchor free from the bottom then the voltage pop back up on just the reeling in process.....

If you have 6 gauge wire already in place and that's what the windlass company specifies for the length of wire your running, as I said earlier, I think your in good shape.

I would also encourage you to check every connection, good lug crimps, clean terminals.

Maybe we can get some additional input from some of the other guys who have been thru this before......

Good luck with the install......it will work just fine.

It should, but I hate doing projects twice.

I once decided I wanted to rebuild an old Harley. So I bought an ol' 52 Panhead kicker. Took it all apart and started the rebuild process. Would have taken a mechanically inclined person 2-3 months to do. Took me 9 months. I had to take the tranny off 4 times because I kept forgetting or overlooked a step.

Ever since then....I check, rethink, recheck, double think.... It's a curse.

 

[evetsmd]

Dale had 2 issues in his post - wire run and max % drop. You told us 53' which I assume is the single wire run x 2 and 10% max drop.

Below is the wiresizer calculation based on that info and using 6 gauge and then 4 gauge wire.

6 gauge still looks good to me.....well within the 10% max drop number. Take a look at the 4 gauge calculations and you can see what it buys you.

Bottom line is you have to be happy with the install......if you feel 4 gauge is better and your willing to spend the money and time to install it.....then do what will make you feel good!

Have fun!

 

[Megabyte]

I cannot add anything to the electrical discussions here, but I can add a couple of related tidbits regarding the operation of your windlass.
In order to extend the life of the windlass and all the items related to it, a couple of caveats regarding operation might be useful.

First, don't use your windlass to winch your boat around against wind, current, or the bottom. Use it to raise (or lower) your ground tackle only. Using the windlass to pull the boat through the water and to power the hook off the bottom puts an awful lot of strain on the windlass motor, the electrical system, the gypsy, and the rode. Besides, it just isn't necessary.

When you're ready to raise anchor, bump the motor into gear and head into the wind (or current) taking the pressure off of the rode as you take up on the line. As you get closer to vertical (zero catenary), stop the windlass take-up for a moment and gently power forward on the motor.

This action will reverse the direction of pull on the hook and will back it out of the bottom using the weight and momentum of the boat, not the power of the winch.

Once the hook is free from the bottom, use the windlass to power the anchor and rode up, and onto the boat.
Using this method places much less strain on the windlass, and will extend the life of all the involved equipment.

Happy hooking!

 

[DaleH]

6 gauge still looks good to me.....well within the 10% max drop number.

I agree 100% if/when using that data set ... 35-amp load and 53' total run, #6 AWG wire. Even at a load of 50 amps and a circuit length of 60' ... that #6 is still < 10% voltage drop.

Just make sure the wire that is there is in GOOD condition and that the ends are properly sealed to prevent corrosion wicking up the leads ...

 

[TheOtherLine]

OK. Well, I'm satisfied that I will be ok with the 6 gauge wire.

Took the old windlass off today. That was a BEAR. The access to the nuts securing the windlass to the pulpit is through the rode locker in the berth.

My arms were inches short of reaching the furthest one forward. I had to take a 1 foot piece of PVC and shove the ratchet handle in it to reach the nut. I don't know how I'm going to get those nuts back ON. :? I was literally neck deep in the locker.

Then, I had to disconnect the 6 gauge wire from the 12 gauge wire that is connected to the windlass. It was shrink wrapped. Cutting it off at the connection was ok but, try removing the shrink wrap! Mind you, you can only get ONE arm/hand in there!

No, you can't pull the wires through and make your connections at the top because the holes are only big enough to feed the 12g wire through.

Got the caulking and gasket remains razored off and had to cover the holes up as it started to rain.

Tomorrow, I'm going to seal up the old bolt holes with Marine Tex and drill out a larger hole for the rode.

Next day I am going to try and make the connections for the new windlass with one hand in the rode locker. :shock: I don't have enough lead on the 6 gauge to pull it out of the locker and make my connections.

If any of you mechanically adept guys have any tips or tricks, I'm all ears.

This project is turning into a love/hate relationship.

I don't know how they got the d@$% thing in there in the first place...

 

[DaleH]

No, you can't pull the wires through and make your connections at the top because the holes are only big enough to feed the 12g wire through.

Since you cut off the old windlass, I'd open up the holes in the deck large enough to feed a heat-shrinked 6-AWG wire through. Plus see below.

I'd rather that fool-proof connections and have to goop a hole in the deck than be worried about sub-par connections, given your limited accessibility.

I don't have enough lead on the 6 gauge to pull it out of the locker and make my connections.

If any of you mechanically adept guys have any tips or tricks, I'm all ears.

Simple ... disconnect at the battery source end and pull slack wire up to the bow, make connections, and then pull the wire back to the power source.

 

[TheOtherLine]

I'd open up the holes in the deck large enough to feed a heat-shrinked 6-AWG wire through. Plus see below.

Simple ... disconnect at the battery source end and pull slack wire up to the bow, make connections, and then pull the wire back to the power source.

Now why didn't I think of that? I love this site

 

[TheOtherLine]

Any tips on how to splice/connect 6 gauge wire to 12g? I can't seem to find any butt connectors that reduce that much.

I could just strip both wires, twist, solder and shrink but I thought maybe there is an easier solution.

When I disconnected the original windlass wires, they used some sort of trianguler, cone shaped metal material. The 6g inserted into the wide end and the 12g inserted into the pointy end and they just crimped the metal thing, then shrinked wrapped.

I looked all over for those and couldn't find any.

 

[DaleH]

Use a 6-AWG connector and TWO pieces of 12-AWG to fill the connector, One is a 'dummy' that is stripped but doesn't connect to anything. Make SURE to seal the other end of this off.

I don't recommend soldering on marine connections ... makes them brittle!