Winch amparage question

[redrodant]

Anyone know how much amperage a winch will pull??? and is there a cutout switch rated hi enough???? what about multi motored winches "gigglepins" other brands are valable?? what do these draw????

Also do all winches come with overload safty's ????

[western]

use one of these big brass switches 6th from top

will happily handle the current draw of electric winches.

[errol209]

A six horsepower (6HP) 12 volt electric motor will pull just under 380 amps under full load (63 amps per horsepower at 12 volts).

[zardos]

A six horsepower (6HP) 12 volt electric motor will pull just under 380 amps under full load (63 amps per horsepower at 12 volts).

It depends on the motor and efficiencies (74 amps per horsepower at 10 volts)

But Warn quote 480Amps at full load (http://www.warn.com/truck/winches/95xp_winch.shtml) for their XP motor.

So there is no realistic way isolate or cable a twin motor winch for full load continuously (you would need about a 300sq mm conductor and 4 isolators )

So what happens if you run a cable or cut-off switch above it's continuous current rating capacity, it heats up to above the melting point of the insulation, but this takes time and depends on many factors (e.g. current temperature of the conductor, load, etc)

I have melted one of these 250A/2500A for 5 seconds cut-off switches using a twin motor XP winch, but then the contacts stopped connecting.

I've not had a problem with my 70sq mm cable (which is rated to 485Amps) on my twin motor setups.

Also note that a twin motor winch won't necessarily draw more power (with the same gearing) than a single motor winch, as the power require is proportional to how stuck you are

So be mindful of how hard and long you run your electric winch.

[errol209]

All points taken, but just for reference, this is heaviest duty isolator I could track down at a believable price. Not terribly user friendly though, but it's rated in excess of your cables?

[MrHT]

if you look deeper into your question and start to look at why people are running 24v through 12v motors.

it's ok saying the motor pulls this much ampage but you have to look at whats suppling? the connections between them? and how stuck you are. as it's been pointed out a twin motor will take less effoert to retrive a stuck motor than a single

[zardos]

Actually the lowest rating link in the winch wiring is the solenoid.

The AlBright DC88P sold by places like Devon, Gigglepin, etc is only rated to 100Amp continous (http://www.albrightinternational.com/lang/en/products.php?ID=587)

Even the Extra Duty version (L model number for Large Contact tips just increases the life not the current rating)

The biggest albright you can get handles only 400A continuous but that weighs in at 3.4Kg as is not Protected (P model number) to IP66 standard

It is also more common for the albright's to stop working, which is why I carry 2 spares. (they also tend to weld themselves ON, which is where the easy to reach cut-off switch comes handy )

[zardos]

If you are really stuck there is an easy way to help without increasing the strain on motors, wiring, battery, rope, etc.

That is to do a double line pull (then you just need to be worried about what your pulling against )

[errol209]

A little peripheral digging (sorry, but I find intriguing that the world can make a device capable (in theory, of course) pulling something around 1000A but doesn't make a device which can control it!) reveals that contactor continuous ratings are reliant on heat dissipation (no surprise) and this is acheived by setting minimum square areas for the connecting cables.

E.g. Tyco, who make a continuous 500A IP66-equivalent SPST contactor (yours for ~£100, and you'll need four) suggest that to actually run at 500A you need 150mm² cable to carry the heat away, bigger at higher currents.

I suspect that you could construct an 80% duty 600A reversing contactor (solenoid) if you wished...

[Boothy]

The only time you will pull full current is at a stall, so normally the current is a lot less.

I use the isolater that you refer to, but I use a pair in parallel so both switches actually only do half the work.

[western]

using 2 would IMHO be a bit of overkill, my husky hasn't worried the 250amp isolator

[zardos]

A little peripheral digging reveals that contactor continuous ratings are reliant on heat dissipation (no surprise)

Yes and 2 70sq mm cables are better than one 140sq mm cable (70sq mm circumference is 30mm vs 42mm for 140sq mm), so there is more area to conduct away heat.

But multi core, ducting, ambient temperature and bundling cables together affect the current rating as most are quoted as in free air current carrying capacity.

What also helps is the melting point of the insulation, as a higher temperature allows a bigger thermal gradient and thus more heat is transferred away.

[Boothy]

You may be right about the overkill but I've burn the contacts out on the switches before with a bit of extensive winching, espicially on a three winch set up,

so after I've spent a fortune on diesel dragging the motor half way around the country, an entry fee, followed by a weekend away, and to be put out by a £15 switch then yes overkill is a fantastic tool, a bit like reliabilty really, great when you have it, carp when you don't,,,,,

[redrodant]

You may be right about the overkill but I've burn the contacts out on the switches before with a bit of extensive winching, espicially on a three winch set up,

so after I've spent a fortune on diesel dragging the motor half way around the country, an entry fee, followed by a weekend away, and to be put out by a £15 switch then yes overkill is a fantastic tool, a bit like reliabilty really, great when you have it, carp when you don't,,,,,

Thank for all the info So what switch will best suit challenge trucks so they comply with the new MSA regd for jan 2011. Basicly it has to cut all electrical power, including all winches, and kill the engine.

[zardos]

Thank for all the info So what switch will best suit challenge trucks so they comply with the new MSA regd for jan 2011. Basicly it has to cut all electrical power, including all winches, and kill the engine.

I don't know what is "new" for 2011, but the regs have always said isolators to cut of all electrical power including winches, but most people do this with multiple isolators.

So I would use from VWP or other places.

Ref: BISALP

to cut off engine and main car electrics, protecting the alternator

Then one of Ref 60550

for each winch.

I also make sure that the albright solenoids are powered from the main car electrics, so that cutting the main car electrics also switches the winches off(the Ref 60550 isolators are an alternative and or backup isolator for the winches)

[redrodant]

The new rules seem to state 1 isolator for all electrics!

P58.2.4. Isolate all electrical circuits. If you have an electrical winch then yes that includes that. We haven't specified that the kill switch must be to K8, and yes you need to use an appropriate rated switch that is wired to do that job.

2011 regs link

[FridgeFreezer]

Could the kill switch disengage one or more HD solenoids for the winches though, or does everything have to go through one switch?

[Boothy]

This is how I have mine,

The main vehicle isolater switch also isolates the solonoids (albrights) so in theory kills the winches

So the 2 (in parallel) winch isolater switches just kill the 70mm power to all 3 allbright solonoids, which co-incidentally are fed of a seperate pair of Optima yellow's and a seperate 100Amp alternator.

The vehicle has its own red Optima and again another 100Amp alternator (which can in a moment of crisis) all be linked together if an alternator fails, this supply controls everything except the winches, i.e fans, ecu, lights, water pump, fuel pump, starter, in fact everthing.

Easy in it ????

[errol209]

The main vehicle isolater switch also isolates the solonoids (albrights) so in theory kills the winches

And in 99.999999% of practice too* - this is exactly how I'd do it, allowing you to kill the winches from any convenient stop switch too.

* You're very theoretically left with mechanical damage to the solenoids stopping them from disengaging, but I doubt this has ever happened?

[FridgeFreezer]

Just read the 2011 regs link above, bl**dy hell there's a six-pack of cans of worms right there!

Winch pull ratings, hydro steer max pressures, trayback legalities, compliance with C&U... and no indication of how organisers coud practically enforce / scrutineer any of it. Not that scrutineering seems to be done very thoroughly anyway from the state of some of the vehicles out there which are allowed to compete.

Also slightly concerning that the MSA Reg writes in dyslexic txt-speak

[errol209]

Just read the 2011 regs link above, bl**dy hell there's a six-pack of cans of worms right there!

Winch pull ratings, hydro steer max pressures, trayback legalities, compliance with C&U... and no indication of how organisers coud practically enforce / scrutineer any of it. Not that scrutineering seems to be done very thoroughly anyway from the state of some of the vehicles out there which are allowed to compete.

Also slightly concerning that the MSA Reg writes in dyslexic txt-speak

I wondered about some of this: I assume that hydraulic test points, regular winch rope proof tests and mandatory IVAs for un-registered vehicles (I can see HMGov just loving that one) are going to make it all a bit tedious

[redrodant]

I wondered about some of this: I assume that hydraulic test points, regular winch rope proof tests and mandatory IVAs for un-registered vehicles (I can see HMGov just loving that one) are going to make it all a bit tedious

Here's a reply from Ian for a question i posed. I read this as we need a lot more marchells on events!!!!!!! Or a lot less Punches

Dear Dave

Winches are not to used or deployed unless in an area made safe and under the direct control of an official of the event.

Punch Hunt type events are not Challenge Events per say and indeed this is where a lot of confusion is. The Cross Country Committee is currently preparing amendments to the Orienteering regulations which will allow for a Punch Hunt type of event although the purpose of the event is to navigate and drive to the objectives.

If the event requires the use of a winch then it is to be in an area exclusively for that purpose and suitably taped.

The reduction in the area when using a synthetic rope is in respect of the area to the side of the winch deployment and behind. There is no formula but that of common sense. The objective of the area is to exclude persons other than the competing crew and officials from the potential whip of a failed winch cable. Since a synthetic rope tends to discard stored energy with less drama and has little or no whip, the area behind the vehicle and to the sides may be reduced accordingly.

Regards

Ian R Davis

Regional, Rallies &

Cross Country Executive

The Royal Automobile Club Motor Sports Association Limited

DDI 01753 765039

www.msauk.org

MOTOR SPORTS HOUSE I RIVERSIDE PARK I COLNBROOK I SL3 0HG I ENGLAND

TEL: 01753 765000 FAX: 01753 682938

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-----Original Message-----

From: Dave Ellard [mailto:dave@rngp.org]

Sent: 16 August 2010 21:35

To: Ian Davis

Cc: Dave Middleton; Ian Potts

Subject: Re: Challenge rules changes

Please can you answer a queary i have.

Basicly we seem to be more and more Just hang punches on trees, not

using any tape,or boundries at all, and just letting the competitors

find there own way too and away from the punch the best way they think

is appropriate. How will this work with the steel cable rule?????? .

Also when u say "if synthetic rope is specified in the sr's then this

distance may be reduced" what sort og reduction do u have in mind???

[zardos]

The new rules seem to state 1 isolator for all electrics!

P58.2.4. Isolate all electrical circuits. If you have an electrical winch then yes that includes that. We haven't specified that the kill switch must be to K8, and yes you need to use an appropriate rated switch that is wired to do that job.

2011 regs link

Now is that the appropriate break current rating or thermal current rating?

As it is to isolate the electrical circuits then I would use the break current rating (on a DC88P albright this is 800A instead of the 100Amp to 180Amp thermal current rating)

[Daan]

And in 99.999999% of practice too* - this is exactly how I'd do it, allowing you to kill the winches from any convenient stop switch too.

* You're very theoretically left with mechanical damage to the solenoids stopping them from disengaging, but I doubt this has ever happened?

Not when you have the problem of contacter weld it wont.

[FridgeFreezer]

What Daan said.

The kill switch may be able to break 800A but if it melts when your winch draws over 180A for a few seconds no-one's going to be fitting them, or they'll be fitting them for scrutineering and either not wiring them as they should or bridging them out as soon as the scrutineer moves along.

From the e-mails above it seems to suggest that the MSA don't really cover winch challenges as they are currently run, which makes me wonder how legal/insured any of the previous events have been - if someone dies and the MSA are going to walk away things could get a bit sticky for organisers?