How much juice does a winch solenoid draw?

[BogMonster]

It's not strictly a LR question, but I need to know roughly how much current a typical 4x4 winch solenoid as fitted to an 8000lb+ electric winch will draw through the handset. I've no idea if the coil takes a fraction of an amp or 20 amps when energised? I know the Milemarker hydraulic solenoid only takes a couple of amps, but not sure about electric winches.

I'm not talking about the current drain of the winch, just the solenoid itself.

Any thoughts please - or actual measurements? What I want to do is use a cheap £25 wireless winch controller to control the tipper mechanism on an Ifor Williams tipping trailer to do away with the wired remote which is a pain. The Ifor remote is similar to a winch remote, and appears to switch a larger solenoid powering the tipper motor. I can measure the actual draw, but I don't know how it compares to a typical winch solenoid and I'm struggling to find out what the cheap remotes are rated at. The Lodar I have switches up to 15 amps, but it's also ten times the price of the one I am looking at, so assuming the cheap ones can cope with the same might be silly.

[Bowie69]

Pretty sure I measured an albright-type solenoid at 10A, and therefore didn't bother relaying it.

[Boydie]

The coil will only draw a fraction of an amp. If you have a good multimeter it's easily checked. I would guess at less than .25 amps

[Bowie69]

Er, but I measured it at around 10A ...

[Les Brock]

V I

----

R

Volts Divided by coil resistance in ohms, should give you current !

Eg

12.8v Divided by 0.5 Ohm = 2Amps

Plus a bit of current inrush when it energised

[AMB]

V I

----

R

Volts Divided by coil resistance in ohms, should give you current !

Eg

12.8v Divided by 0.5 Ohm = 2Amps

Plus a bit of current inrush when it energised

Slipped a decimal point Les! I suspect that the confusion between 10A and 0.25A is that between a solenoid/contactor and a relay. 2-3A for a 200A contactor seems about right

[Les Brock]

My maths was always pants, and it's not improved with age !

[BogMonster]

Winchmax have replied and said "The remote controls are designed to produce a 12v signal only and are not really designed to be used as a stand alone switch - they would however be able to manage 2-3 amps."

I guess I'll need to measure the current drain on the Ifor with a meter and see where it falls in the range of outcomes. I assume it's a solenoid/contactor for the pump unit and a solenoid for releasing pressure to drop the box again - you can hear that clunk when it energises. I was thinking 2-3 amps would be about right for a typical Albright type solenoid, but wasn't sure. Thanks.

[Anderzander]

Er, but I measured it at around 10A ...

Strange !? I'm pretty certain mine is running with a 5 amp fuse.

[Bowie69]

Curiouser... Giving it more thought, IIRC it was 8A, and I fused to 10, so not as far from 5 as it might be, but.... 5A fuse for you, well if it works

[zardos]

Given the specs of a DC88 (http://www.albrightinternational.com/files/downloads/catalogues/DC88P-1000.pdf)

It says the coil power dissipation will between 7 and 30 watts depending on the exact model

Thus using the worst case power figure would give a current of 2.5Amps at 12V but as we know that while winching it is possible for the voltage to drop, so on the safe side lets say 30W / 10v = 3 Amps

[zardos]

My guess from there descriptions of the coil types they would be
Intermittent (INT): Up to 70% duty cycle, up to 15 minutes continuous

or possibly

Highly Intermittent (HO): Up to 25% duty cycle, up to 3 minutes continuous
energisation

I don't think companies that order these go for
Prolonged (PO): Up to 90% duty cycle, up to 54 minutes continuous
energisation
or
Continuous (CO): 100% duty cycle. Continuous operation.

An Intermittent (INT): Up to 70% duty cycle, up to 15 minutes continuous
coil type would put the current at more like 1.6Amps

But unfortunately the coil type is probably encoded in the second number of the model number e.g. DC88-276P from Devon 4x4 http://www.devon4x4.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=7&category_id=127&option=com_virtuemart&Itemid=14
(the P part means Protected to IP66 Compliance, an L would mean Large contact tips)

The higher wattage of the range is probably the initial power need to oppose the return spring and move the contactor, the low wattage is probably the sustained power usage which just needs to oppose the return spring.

[Escape]

It's not strictly a LR question, but I need to know roughly how much current a typical 4x4 winch solenoid as fitted to an 8000lb+ electric winch will draw through the handset. I've no idea if the coil takes a fraction of an amp or 20 amps when energised? I know the Milemarker hydraulic solenoid only takes a couple of amps, but not sure about electric winches.

When I fitted a Milemarker to my Defender I added a (cheap) wireless control as well. But it didn't work, it would energise the solenoid and immediately cut out again because the currect demand was too high. It worked fine with electrical winches, so the solenoids in the valve block must have a higher current draw. You could have the same problem with the tipper, depending on the size of the valveblock.

[BogMonster]

OK, thanks, that's useful to know. I have a Lodar 9000 on my Milemarker which works perfectly but that has solid state switching for up to 15 amps so not a problem. But I don't want to spend over £200 on this, I don't use it often enough to justify that much. If I can't get a cheap wireless to work then I'll probably just hard wire a waterproof toggle switch into the metal box.

[mick the digger!]

Can you still not use a cheap wireless remote to trigger a relay which in turn energised the coil on the solenoid valve or am I missing something?

[BogMonster]

Yes I probably can, but given that it all lives in a not very weatherproof metal box under a trailer which will be damp from condensation, rain, road spray etc, I'm keen to keep the electrics to a minimum. Which I know makes it a dumb idea to fit a wireless remote, but I want one

I've ordered a couple of waterproof high current toggles as a backup, so that might even end up being the solution - as long as it gets away from the tanglefest of the current lead, I don't mind...

[Boydie]

My 12000Lb Warne winch control circuit is protected by a 2 amp mini CB. It hasn't yet popped. 2 amps being the smallest CB available. The winch motor power supply is protected by a 85 amp CB and that gets very warm but again has never broken circuit.

[zardos]

My 12000Lb Warne winch control circuit is protected by a 2 amp mini CB. It hasn't yet popped. 2 amps being the smallest CB available. The winch motor power supply is protected by a 85 amp CB and that gets very warm but again has never broken circuit.

The 85Amp CB probably has welded itself shut :-) as winch motors can draw up to 440Amps (http://www.warn.com/truck/winches/src/M1200.shtml) , OK given that you have a 12000Lb so the gearing is lower so power per Lb will be lower, but Warn state that it takes 67Amps just to do a no load line spool then 85Amps is far too low.

[BogMonster]

The 85Amp CB probably has welded itself shut

That was what I was thinking

[Boydie]

Nope, just checked it when I read your comment's, hit the button and it opened - zero power, closed it - manual re-set - operated said winch with a tree as a tether and it pulled the car forward.

[zardos]

Was the car on flat hard ground, or in mud or up a hill or did you have the foot on the brakes?
If just on flat ground then the effort the winch would need would be minimal with the brakes applied.
I would expect a winch to pull the car along with the brakes on, on anything but tarmac.

[Boydie]

In this instance, yes, slight uphill gradient and on tarmac, but the last time it was used in anger it dragged the car 150 meters up a hot soft sand dune in the Simpson desert using one of the spare wheels as a sand anchor. The car was bogged up to just below the differentials. The relay will take (according to the information sheet in the box) 450 amp spikes and 100 continuous amps without the circuit breaker breaking circuit. It quotes a 5 minute re-set period.

[zardos]

The detailed specs look of the circuit breaker look slightly better but still very under rated for the winch.
I would run 3/4 of these in parallel to give you the right load protection for the winch otherwise at some point you might find yourself stuck and the circuit breaker is tripping out.
With the type of circuit breaker you describe with parallel ones you can at least manually trigger some of the multiple number to give you selectable load protection, so you could run most of the time at 100Amps but can easily increase the capability if needed (of course if you are really stuck with just one circuit breaker then you could re-wire in time of need to bypass it)

The reason I suggest this is that a long time ago I bought a vehicle with a winch and hidden in the wiring was a bunch of auto resetting circuit breakers rated in total to 120Amp, when winching up a about 45degree hill with good going it just cut out half way up (the reason was the load had increase due to the number of wraps of rope on the drum).
I then had the fun of securing the vehicle so I could re-rig with a double line pull, which is not always easy and takes time.
After that the first thing I did was remove the circuit breakers when I found them.

[Mo Murphy]

Interesting, I have nothing protecting my winch.

What would you learned chaps recommend for a 10000lb winch, worst case scenario ?

[zardos]

So on my 3 winches I just have manual isolators no circuit breakers, as the possible current load could be as high as theoretical 1000Amps for one winch

So Given that most winch motors are rated to draw up to around 500Amps then if you want to get the max out the the winch then this is the level of protection you should aim for.
BUT you should take in to consideration the size of the wire used to connect the winch, it is common to use 35mm squared cable which usually has a constant current rating around 240Amps under normal cooling conditions (but it will take a higher load for shorter periods of time)

In the past I've not seen any suitable single circuit breakers, but a google today shows http://www.ebay.com/itm/300-AMP-12V-DC-CIRCUIT-BREAKER-REPLACE-FUSE-300A-12VDC-CAR-AUDIO-STEREO-300AMP-/280633585070

So may be 1 x the 250Amp version if you feel the need for circuit protection and want to protected within the constant current rating of the weakest component.
or
If you are like many winch users, using the thermal buffer of the components then protect against a load around the max expected load e.g. 2 x 250Amp circuit breakers would be OK.
(What I mean by thermal buffer is that 35mm2 wire is rated to carry 240Amps constantly, this means the heat generated by the load minus the heat dissipation of the cable stabilises at a temperature lower than the melting point of the cable/insulation, this temperature that it stabilise at take time to reach, you can draw more for a shorter period of time before it hits this temperature, but you can only do for so long before you have to let it cool or reduce the load and as winch power loads tend to peak for short period of times this is acceptable as long as you are aware that you will need to rest the winch when it is using a lot of power)