Electric anchor winch--cable size?

[lydiamight]

I am proposing to fit an electric anchor winch during the winter. Chosen windlass has a 1000w motor and according to the manufacturers website "draws 50-80 amps". Cable run from the battery is around 4.5 to 5 metres. Can anyone reccomend what cable size I should use, or point me in the direction of a website where I might find the answer. I would prefer to go one size up on the cable rather than skimp. Can anyone also help with cable suppliers? It's been suggested to me that welding cable is a good and more flexible option.

 

[savageseadog]

Welding cable is the best option but most that I've seen is plain copper tinned copper is best but less common. so make sure you treat the ends or see if you can get the tinned stuff

 

[galloper]

It should have a cross-section of equal or more than 35 mm2.Multi wire cable (welding cable) 35 mm2 is ok.

 

[CSFenwick]

You need to take the total run there and back so sounds like 10m You should take the 80A figure given that 1000W/12v = 83A. For 80A and 10m run the voltage loss tables give AWG 0 (50mm2) for 3% voltage loss or AWG 4 (20mm2) for 10% volt drop.

Assuming you need to get fully 12V to the windlass, if you go with AWG 4 and your battery is actually at 12.5 volts then the windlass will only see 11.25 volts. You’d need a fully charged battery (13.3v) to get 12v at the windlass.

It comes down to what money you're willing to spend but if this was being done professionally they'd use AWG 0 in tinned multicore copper cable. Probably cost upwards of £10 per meter from Merlin or other specialist supplier. Non-tinned would be a good bit cheaper but given it's going to be connected to the windlass, corrosion seems a distinct possibility.

Some people recommend a dedicated windlass battery in the forepeak to reduce the cable run. Given the cost of the cable you could probably afford to buy the battery instead. You'd still need to run cable from the alternator of course but the size, cost and weight would be far less.

You pays your money and you makes your choice.

 

[pvb]

Separate battery...

The separate battery is a bad option. Too much extra weight, right where you don't need it. It needs a cable to charge it (ideally with isolation from the other batteries). You still need a fairly meaty cable, because the windlass can draw considerable current through the charging cable if the engine's running. And you need extra protection, in the form of fuses/breakers at both ends of the charging cable. By the time you've done all of that (plus constructed a strong and ventilated housing for the battery) it's usually cheaper just to run big cables.

As many people only use the windlass when the engine's running, some voltage drop in the cable is acceptable. I'd use 35 sq mm cable.

 

[jerryat]

Re: Separate battery...

Totally agree with your post. This idea of siting a windlass battery right forward is seldom thought through properly yet is regularly recommended on the forums!

As you correctly say, it's definitely better to run appropriately sized cables forward and avoid all the hassle.

 

[kengill]

When I fitted our windlass I used a Lofrans 1000W windlass.

I used 80sqmm twin welding cables which have an additional clear plastic sheath. The cable was not tinned but I used sealed end brass terminals with shear bolts and after tinning the terminals with solder I fitted shrink wrap round the terminal and extended it up the cable a few inches.

If fitting a remote control remember to have it on a separate circuit so the voltage drop under load doesn't switch out the windlass!!

Fair winds
Ken

 

[GMac]

I work closly with some winch makers. All complain of customers using too small a cable and doing nasty things to their wnches.

Ask the manufacturer and use what they recommend.

 

[halcyon]

Re: Separate battery...

For passing interest, the relay we do for charging a bow battery interfaces with the winch. Thus if the bow battery is on charge, the relay drops out on energising the winch, thus protecting the charge cable.

Brian

 

[pvb]

Sensible kit...

Yes, but you make sensible kit, Brian. Lots of happy boaters fitting a bow battery would never consider the full implications.

 

[andyball]

http://www.furneauxriddall.com/shop/acatalog/Starter.html is very flexible indeed - & prices very reasonable. They also keep spme std cable, but I've struggled to get this in 50mm from them.

to save a bit - buy 10m online -(one colour for both & mark the + with a bit of red sleeve or even tape). they will likely sell other lengths - but you'll need to telephone them.


neither are tinned - but glue-filled heatshrink ( also from them) over the crimped part will make a great improvement in stopping corrosion - if applied correctly.

as to size - I'd use at least 50mm sq - more if you might be running/abusing the winch so it's close to stalling - which of course you shouldn't.