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Windlass wiring

3K views 21 replies 10 participants last post by  camaraderie 
#1 ·
I'm sure this bring out many differing opinions.
Windlass installation - APPROX AMP DRAW = 90-130(12V)
Trying to decide - 10% or 3% loss
According to the books:
@3% 100 feet of cable = 4/0 cable
@10% 100 feet of cable = 2/0 cable

Marine Battery cable for these sizes are in the 7 - 10. dollars a foot range... YIKES

If use welding cable - 4/0 is about 3.14/ft delivered.
So I can use the 3% loss figures for more power to the motor but I risk the corrosion issue of having welding cable.
Although I could use welding cable where it would be protected - bilge etc... and use the tinned wire for the connections where exposed..
Where to put the money - bigger cable vs better wire??
Whats a sailor to do.
alan
 
#4 ·
If you can't place the battery forward, you're better off to go oversized than not. And use marine grade cable, it's worth it in the long run.
 
#5 ·
Definitely use marine grade cable, especially on a cable that heavy. Do you have any idea of how much of a fire hazard the welding cable would be after it starts to corrode??? A small battery up forward, with more modest cabling is probably a better way to go, both weight wise and logistically. Also, the bilge is not really protected for wiring on most sailboats, having water in most... and the real problem with corrosion is the humid salt-laden air...which is pretty much unavoidable on a sailboat. If you want to know how bad it is...take a penny and tape it out on the nav console and see how long it takes to start turning green.
 
#6 ·
#7 ·
PBzeer said:
If you can't place the battery forward, you're better off to go oversized than not. And use marine grade cable, it's worth it in the long run.
I'm facing this very decision, and I have decided that a dedicated flooded battery up forward with a separate charger (a recycled 20 amp West Marine) and very short cables is the way to go. I will top it up with solar panels or a Honda genset underway. This seems elaborate, I know, but my main house banks will be six AGMs low and in the middle of the boat (22 foot run forward to the forepeak "workshop", and my charger/inverter system would need resetting and then rerouting just to charge a flooded cel forward, plus the fact that I want to keep my collision bulkhead as intact as possible.

This way, I will use maybe 20 feet of 2/0 AWG for ALL my batteries and to/from the inverter. Seems the best plan rather than snaking heavy cable forward.

Also, if the windlass battery goes kaput, I can always snatch a topped-up AGM and it's a "drop in".
 
#8 ·
Valiente-

Why not put a dedicated AGM up forward, that is of the same type/size as the ones in your house bank. That would certainly make dropping one in for the other easier, and AGM batteries are better at holding their charge over long periods of time, which is often the case with a windlass... you drop the hook, stay a few days, raise the hook, make a long passage... etc.
 
#10 ·
AWG wire sizes

This info is easily available on the internet--just Google *AWG wire sizes*

AWG 0000 (4/0) is .46-inch diameter and can carry about 300 amps

AWG 4 is .2043 in diameter and can carry about 60 amps

Remember, the higher the AWG wire size number, the smaller the wire.
 
#11 ·
Difference between 4awg and 4/0? Oh, about $15/foot and your pinky versus your leg! In wire sizing (typically used on a boat) it goes from about 20awg (I don't know where you would use this, but mention it) down to 1, then 1/0, 2/0, 3/0, 4/0, 250 mcm, 350 mcm. I think MCM means (MuCho Money)... but I don't have a freaking clue what the engineers think it means. I have not had to buy any of that and have gotten away with 4/0 on my inverter. Remember you have to use marine grade wiring (tinned).

If you are going to do, well, any wiring yourself on your boat PLEASE read some good books and seek the expertise of some folks that are very experienced. Nigel Calder is probably the best (Boatowners Guide to Electrical and Mechanical Systems... or something like that). You cannot miss it. The Electrical Bible is good too, but I cannot remember who wrote it.

I learned my stuf hands-on with my pops through rewiring houses then learned the differences that apply to a boat (and there are a bunch, not to mention direct versus alt current). Just please be caredul with the Air conditioner install or if you are going to run that kind of amps through a windlass.

You seem like a very nice guy and I don't want you in the Obits!!

- CD
 
#12 · (Edited)
1970Columbia34 said:
Can some one explain what the diffrence is between say 4awg and 4/0awg wire. and which is need for a windlass?
It depends on whether you're going to put a battery forward, near the windlass or whether you're going to run it off the house bank. If you're putting a battery forward, then you could probably get away with 4 awg wire, to charge the battery with... and that might even be a bit overkill... but if you're going to run the windlass off the house bank... then you will want the 4/0 awg wire instead.

ed: Having checked the numbers from the OP first message, the 4/0 is barely good enough and I'd highly, highly advise putting a battery forward, and float charging it off the house bank or off a separate charger for it. A small panel might be a good option.
 
#13 ·
CD what does intalling a windlass which is 12v have to do with my Air unit that will only run on shore power?

I was looking in the Lewmar manual for the Horizon 600 and it stats that if all the wireing for the windlass equals 90' then you need to use 4 AWG (16mm^2) wire, but you guys are saying that is to small. I plan to run the windlass from out house batteries. Thanks for all the help I know I ask alot of questions.
 
#14 · (Edited)
good page to refer to is located here. I believe the wire numbers that we're talking about refer to the the OP's windlass with a draw of 90-130 Amps...

He says he has an 100' run with a 12V load at 90-130 Amps. With 4 AWG wire, the voltage drop is over 6.5 Volts, which will lead to a fire. With 4/0 AWG wire, the voltage drop is 1.31 Volts, which is still a bit high, over 10%, but will probably work. I don't know where he is getting his 3% figure from though. The 2/0 AWG wire would result in a 2.1V drop...which is not a good idea.

I will make the guess that his windlass is a good deal larger than the Horizon 600 you're looking at.
 
#15 ·
1970,

I did not say 4awg was/was not too small. You would have to add up the round trip and check the charts. If they say 90 feet for 4awg, there you go. They know their product, draw, and probably oversize it 20% for safety would be my guess. Lewmar is a good name.

As far as the air conditioner, yes 110, but my point was to please be careful. Misswire something or a loose connection can sure burn down a boat quickly.

Hey, want to have some fun 1970? Start up a new thread right under the anchor thread. It should be called:

Crimping or Soldering? Which is best? It will go on through the night and well into the next few months. You can read it and go ahead and do what you were going to do anyway!

- CD
 
#17 ·
CD- You're evil...evil...and evil... ... funny though.
 
#18 ·
sailingdog said:
Valiente-

Why not put a dedicated AGM up forward, that is of the same type/size as the ones in your house bank. That would certainly make dropping one in for the other easier, and AGM batteries are better at holding their charge over long periods of time, which is often the case with a windlass... you drop the hook, stay a few days, raise the hook, make a long passage... etc.
Because I have a perfectly good about-to-be surplus charger and perfectly good and brand new in 2006 flooded batteries. I may change my mind on this, though, as the ideal thing would be to have identical batteries all around.

I am under the impression that an old-school charger won't maintain the AGMs properly: am I wrong here?
 
#19 ·
Cruisingdad said:
Difference between 4awg and 4/0? Oh, about $15/foot and your pinky versus your leg! In wire sizing (typically used on a boat) it goes from about 20awg (I don't know where you would use this, but mention it)
My old cabin runs on the '73 sloop are at best 18 or 20 gauge, which is stupid with 12vdc incandescents, but perfectly fine if you switch to bayonet-mounted LED clusters.

I won't even get into the original brass fuse box on the AC side or the 10 gauge Romex wiring. Fresh water thinking.
 
#20 ·
Valiente...AGM's take the same charging routine as Flooded. I don't know what you mean by "old school" but as long as you charge bulk at about 14.3 and have a float stage as well you should be OK with anything that works well for flooded deep cycle batts. But...if you've got a 2nd charger and batt already then I guess it is a non-issue for you!
 
#21 ·
Cam-

Actually, the voltages used for charging AGM's is slightly different. Don't believe they should be mixed in a bank for that reason.
 
#22 ·
SD...I believe the charging voltage parameters are actually "the same" depending on who's parameters you happen to read. I think the real incompatability is that the AGM's have wide open AMPERAGE acceptance whereas wet cells need to be charged at about no more than 20% of capacity during the BULK stage...so you can't mix and get good results.
If anyone knows differently... pls. advise and cite the source...would be most interested to know. In the meantime..here's what AMsolar has to say about charging AGM's:
  • The AGM batteries don't like to be pushed over 14.4 volts during "Bulk" charging and want to be held between 13.2 to 13.4 volts during "Float" charging. They can withstand an occasional short duration "Equalization" charge as long as it is less than 15 volts. But don't overdo this as it can be forced to outgas and there is no way to add water back in.
I believe these are the same bulk and float parameters used by wet cells...while EQ charge level is QUITE different but since that is manually initiated shouldn't be a problem. It is the amperage during bulk charge that I think is the incompatibility culprit. (Actually a couple of sources (Ample Power for one) have said you CAN mix flooded and AGM's but most say not to.
 
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