Circuit Breaker Sizing for Winches

Nikkormat

New member
I'm going to be mounting a harbor freight 12k winch on my XJ and I'm a bit confused regarding circuit protection. The stock positive lead includes a block of three 50 amp self resetting breakers, I want to go to a bussman marine style breaker that can be manually disengaged. Should I again go with a 150 amp rating? The charging system is stock except for an AGM battery, my alternator will produce 120 amps on a good day.
 

Superduty

Adventurer
I dunno about the hf winches.

Warn (winch) recommends wiring straight to battery, no fuses or breakers.

Sent from my SAMSUNG-SM-G930A using Tapatalk
 

luthj

Engineer In Residence
A warn 12k winch can pull over 500A. Good luck finding a 12V breaker in that size. A better solution to a breaker is a fusible link. This would be designed to blow in a dead short. The rule of thumb is to have a short section of wire 4 gauges smaller than the main wire. Something around 4-6' is good size. So for a 0awg, a 3awg section would be chosen. You still need to do a very good job protecting the wires from chafing/pinching/shorting.

https://www.whiteproducts.com/fusible-faqs.shtml

The HF unit may get its high pull strength from a very low gear ratio. So it might actually pull a lot less (slower). If you can get the specs from HF, you may be able to get by with a 150-200A breaker. Personally I would compare a winch to a starter motor, and avoid breakers if possible. The last thing you need is a marginal breaker popping during a critical pull.

The existing breakers should have their specs checked. Those breakers may have a significant time delay compared to typical marine style magnetic breakers.

https://www.mikesjeep.com/articles/choosing-a-winch
 
Last edited:

Recommended books for Overlanding

Jupiters Travels: Four Years Around the World on a Triumph
by Ted Simon
From $17.54
Morocco Overland: A Route & Planning Guide - Southern Mor...
by Chris Scott
From $21.1
Tschiffely's Ride: Ten Thousand Miles in the Saddle from ...
by Aimé Tschiffely
From $10.99
Deep Survival: Who Lives, Who Dies, and Why
by Laurence Gonzales
From $9.99
4WD Driving Skills: A Manual for On- and Off-Road Travel
by Vic Widman
From $17.27

DaveInDenver

Expedition Leader
I've used a 250 amp MRBF on my XD9000 in a previous installation. Never had an issue with nuisance opening in a handful of winch sessions. The XD9000 has a max current of 478 amps and the MRBF will hold 200% of rating for up to 60 seconds and 135% of rating for 900 seconds. The 135% rating is where my winch is producing about 6000 lb line pull and by that point I'd need to be concerned with heat anyway after the 15 minutes. I've toyed with going down to 225 A or even 200 A, but that's not enough margin in my mind for under hood temperatures.
 
Last edited:

Nikkormat

New member
Thanks Everyone, Especially Comeup Winches! I've decided to go with a Superwinch Tigershark instead of my existing harbor freight junk. It's max amp draw is only 320 so it should be less taxing on the electrical system and easier to breaker.
 

IdaSHO

IDACAMPER
At the end of the day, a fuse/breaker is designed to protect one thing. The wiring.

Just like a starter motor.... wire your winch with wire that will support greater current than the winch is capable of drawing, and forget the fuse/breaker.
 

Nikkormat

New member
At the end of the day, a fuse/breaker is designed to protect one thing. The wiring.

Just like a starter motor.... wire your winch with wire that will support greater current than the winch is capable of drawing, and forget the fuse/breaker.

My reason to put a breaker or physical disconnect in the circuit is to prevent an electrical fire in the event of a short due to damaged insulation. This can happen due to wearing against a sharp edge or if the wire is pinched in the event of a collision. I've seen a TJ burn to the ground after hitting an elk back when I worked for a friend's tow company. The impact pushed a piece of the radiator frame through the insulation on the winch wiring. No one suspected anything was wrong until flames were licking out of the bent hood, the steam of the punctured radiator concealed the smoke...
 

DaveInDenver

Expedition Leader
At the end of the day, a fuse/breaker is designed to protect one thing. The wiring.

Just like a starter motor.... wire your winch with wire that will support greater current than the winch is capable of drawing, and forget the fuse/breaker.
If you're in an accident or someone deliberately crow bars your winch controller with no fuses you haven't protected your wiring since the battery isn't self current limiting like an alternator. Every conductor should be over current protected ideally.
 

Happy Joe

Apprentice Geezer
If you're in an accident or someone deliberately crow bars your winch controller with no fuses you haven't protected your wiring since the battery isn't self current limiting like an alternator. Every conductor should be over current protected ideally.
...do what you want; when I had uses for a winch, I always installed the relay boxes under the hood (mostly for aerodynamics but also for a cleaner look) the normally open relays keep current from the winch when not in use.
I do all my high current wiring using 2-0 welding cable... Overkill, need to modify the relay boxes to make it fit.

Enjoy!
 

IdaSHO

IDACAMPER
Yep, if you are that concerned, use a switch or a continuous duty relay.

A fuse/breaker is not the solution.
 

mobob

Member
I used a 400A MEGA fuse and holder on my 10k Smittybuilt. It has done some tough pulls over the last five years without any issues. I was mostly concerned about a short due to a collision and it’s cheap insurance.
 

Recommended books for Overlanding

Overlanding the Americas: La Lucha
by Mr Graeme Robert Bell
From $20
Sailing Alone Around the World: a Personal Account of the...
by Joshua Slocum
From $26
The Essential Guide to Overland Travel in the United Stat...
by TeriAnn Wakeman
From $64.95
Road Fever (Vintage Departures)
by Tim Cahill
From $6.99
Top