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Anyone know how to prevent this.....

Started by FarmingSawyer, December 02, 2014, 06:02:00 PM

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FarmingSawyer

Winching some cedars out today and I looked down and notice the negative terminals on my winch battery was melting......
I'd only used the winch a 1/2 day, but it was running hard part of the time--I wasn't using a block to double the force like I usually do.

I caught the negative wire heating up the other day, but nothing like this.....


 
Thomas 8020, Stihl 039, Stihl 036, Homelite Super EZ, Case 385, Team of Drafts

dgdrls

check your connections at both ends of each cable and just below the connections to be sure there is no acid build-up on the cable
under the insulation.
Resistance test your cables and make sure they are sized to carry
the full amperage load the winch will pull.

I would use the pulley block just to make life easier on the Winch/Battery  too.

DGDrls

thecfarm

Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

Ludo

Cool! A Physics question!  As current is increased heat is produced not at the same rate but at a rate 4x's greater.  The actual equation is Q=I^2Rt, it would be read as Heat (Q) is equal to the current squared (measured in amperes) times the resistance (measure in ohms) times the time (measured in seconds). So when you are really pushing an electric motor the current goes up to supply the power, when that happens the amount of heat generated not only increases but is increased at a rate of 4:1 when compared to the ampere draw.  Not only that but when you increase the temperature of the wire (because of more current) the resistance also goes up causing more heat- a vicious cycle!! Let's say that a motor running at 4 amperes produces 1,000j (joules) of heat, if that same motor is pushed and draws8 amperes, it then produces 4,000j of heat!  In the real world it would be even more. 

So, the fix....  yes, make sure that you have a nice and clean ground but more importantly, make sure that the contacts between the battery and motor are solid and in full contact, not just a little "metal on metal".  If it happens again, replace the leads to and from the battery with larger diameter copper wires.  Why? Because resistance is inversely proportionally to the cross sectional area of a wire.  If you replace a wire that has twice the area, the resistance is halved, cutting the heat produced.  Remember that the area of a circle is 2pi r^2, so you only need a slightly bigger wire to double the surface area (the radius is squared like the heat equation). If you double the size of the wire in cross section, the resistance would be 1/4th, thus negating the production of the heat. 

Sorry for all of that.  Clean all the connectors and replace the leads with larger wires!   :D

beenthere

south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

kelLOGg

Quote from: Ludo on December 02, 2014, 07:14:34 PM
Remember that the area of a circle is 2pi r^2

pi r^2. You must have "fat fingered" that.
Cook's MP-32, 20HP, 20' (modified w/ power feed, up/down, loader/turner)
DH kiln, CatClaw setter and sharpener, tandem trailer, log arch, tractor, thumb tacks

Ludo


drobertson

It's just nice to see some real stuff on here with numbers and proof!  Really, facts are facts, thanks ludo, good stuff there!
only have a few chain saws I'm not suppose to use, but will at times, one dog Dolly, pretty good dog, just not sure what for yet,  working on getting the gardening back in order, and kinda thinking on maybe a small bbq bizz,  thinking about it,

Chuck White

Yea!  Whatever Ludo said, I think!   :-\

Make sure all connections are clean and tight.
~Chuck~  Cooks Cat Claw sharpener and single tooth setter.  2018 Chevy Silverado and 2021 Subaru Ascent.
With basic mechanical skills and the ability to read you can maintain a Woodmizer  LT40!

thecfarm

I think he said to make sure you have a good ground and the wire is the right size for the job.  ;D
Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

Lonely Sawer

To Ludo......WHAT???? Just sayin. Not really. Larger cables and clean terminals. Clean the terminals with baking soda and water while stroking with a wire brush. Works good. 1/4 cup soda to 1 gallon warm water. Take sand paper to the cable ends to clean them up. Just my 2 cents worth.
Norwood LM29
Sthil 020 16" bar
Sthil 039  24" bar
Kubota L3130 HST W/Backhoe
78 Ford F-800 Boom truck
2017 Ram Laramie Longhorn 3500 Cummins 4x4 crew
Yamaha Viking SXS

Brucer

Expanding a bit on Ludo's post -- the formula he gave (Q=I2Rt) applies to the entire circuit, and it also applies to individual sections of the circuit.

The current (I) will be the same through the entire circuit. The time (t) the winch is running will also be the same. That leaves the resistance as the only variable. The most heat will be generated where the resistance is greatest. If that happens to be in a long wire, there will be lots of surface area to dissipate the heat. If it happens to be right at a connection, the heat won't dissipate and temperature will rise.

When I see a battery terminal overheating I first check that the connection is tight. A loose connection increases the resistance which means more heat.

Next I check that the two surfaces in contact are absolutely clean. Dirty terminals means more resistance which means more heat.

If I still have a problem, it may be because there isn't enough contact area between the connecting surfaces. In your case it might help to get a conventional battery cable clamp and use the post connection on your terminal.
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

backwoods sawyer

When using the threaded post I sandwich in two large flat washers, helps with the surface area thing when tightened down real good.

I also use two batterys when running the winch.
Truck battery 25' of cable rated for the distance second battery close to the winch conection. Less peaks and valleys. Others can explain this in more tecnical terms ;D 
Backwoods Custom Milling Inc.
100% portable. . Oregons largest portable sawmill service, serving all of Oregon, from our Backwoods to yours..sawing since 1991

FarmingSawyer

I'm using the factory supplied winch cables.....but perhaps I didn't tighten the terminal nuts down like I shoulda......something about a wrench being frozen to the bed of the truck and frozen fingers......

I'll clean the terminals, add some washers, and scrink things down better today and see how it goes.... Hoping the bolt doesn't melt out of there any more....it's barely in.
Thomas 8020, Stihl 039, Stihl 036, Homelite Super EZ, Case 385, Team of Drafts

Magicman

Quote from: FarmingSawyer on December 03, 2014, 08:10:18 AMHoping the bolt doesn't melt out of there any more....it's barely in.
Then forget the bolt and go to the unused battery terminal.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

woodworker9

Quote from: Magicman on December 03, 2014, 08:45:33 AM
Quote from: FarmingSawyer on December 03, 2014, 08:10:18 AMHoping the bolt doesn't melt out of there any more....it's barely in.
Then forget the bolt and go to the unused battery terminal.

Without sounding like a broken record, Ludo hit the nail on the head.  Just because the cables and connectors are what was supplied with the winch doesn't make them right for your job.  As already stated, and just re-iterating it here, you need to at least change your connectors to clamp on the bigger round battery posts.  The threaded post terminal is obviously not giving you the surface area connection that you need, which is why the resistance is causing your heat, and thus failure.

If it were mine, I'd......

1. Change the connectors to copper post connectors, and see what that does for you.

2.  If still creating heat, go to a larger diameter copper wire.

3.  I would not ever use the threaded terminal that is melted again.  You're just asking for a problem.

Good luck.

Ludo, when I read your post, I had a good chuckle, as it made me remember all that time I spent in EE classes 30+ years ago.  Time flies......

03' LT40HD25 Kohler hydraulic w/ accuset
MS 441, MS 290, New Holland L185

Nate379

Get a good vattery, not that auto zone cheapie.

hackberry jake

Something else that hasn't been mentioned is the voltage on the battery. As the battery gets weaker, the volts drop off. As voltage drops, amps increase. Ever seen a vehicle with a weak battery that cranks over too slow? When people notice that, they should replace it. I have seen too many times where people just wait for it to go out and that is really hard on your starter and your wires. The circuit is held in for a longer time and the amp draw goes through the roof. Make sure you have a good hot battery.
https://www.facebook.com/TripleTreeWoodworks

EZ Boardwalk Jr. With 20hp Honda, 25' of track, and homemade setworks. 32x18 sawshed. 24x40 insulated shop. 30hp kubota with fel. 1978 Massey ferguson 230.

Skidder Kev


reswire

Forget the hoopla and all the physics stuff.  Take it to a retired electrician.  We need to make a living too!! ;D ;D
(We need a little Christmas money) 8)
Norwood LM 30, JD 5205, some Stihl saws, 15 goats, 10 chickens, 1 Chessie and a 2 Weiner dogs...

ozarkgem

Ludo you are a brain! If a 2 trains leave at 2pm---------------------
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

Brad_bb

In addition to good connections and proper wire size for lower resistance, running two batteries would be helpful by cutting the load on each in half, and increasing the amount of power available to run longer.
When using 2 batteries, 1. try to use two of the same battery.  They will have properties close to each other to evenly split the load.  2. Connect the two batteries in parallel, NOT in series.
Anything someone can design, I can sure figure out how to fix!
If I say it\\\\\\\'s going to take so long, multiply that by at least 3!

Ludo

In my other life I teach High School Physics.... lately it's been getting in the way of my milling!  :D

Holmes

Quote from: Ludo on December 04, 2014, 06:43:43 PM
In my other life I teach High School Physics.... lately it's been getting in the way of my milling!  :D
I was wondering where I forgot all those formulas from
Think like a farmer.

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