Old windlass tripping breaker

[adwuk]

I have an old Simpson Lawrence 519 windlass installed, and all of last year it was tripping the circuit breaker, so over the winter I took the thing apart, removed the motor and cleaned up the contacts, brushes. I have also replaced the terminal connectors on the main 50mm2 cable that runs the 8m or so from the batteries to the windlass. I still have to test the voltage drop while the windlass is running, but I have a number of questions, if anyone can help:

- does anyone know what size breaker I should be using for this windlass? The installation is a bit odd as there are 2 breakers, one on the supply and the other on the return. They are both 40amps which seems low and there is nothing in the original book of words that states the size.
- should I remove one of the breakers and only keep a breaker on the supply side?
- when testing the voltage drop at the windlass end, does the windlass need to be under load (i.e. lifting something) or just running?

Another possibility is to simply replace it! The advantage is that I would then be able to use a newer windlass to lower the anchor, rather than simply slip the gypsy - which is certainly safer. That said, the SL519 is pretty simple (old Land Rover starter with belt to WORM drive and onto the gypsy shaft) which makes me think it could go on for a lot longer if the breaker issues are sorted.

 

[CalicoJack]

There is a chap on 01418874122 who used to work for Simpson Lawrence and now sells spares who might be able to advise you.

 

[pvb]

As you say, there seems to be nothing in the SL manual to indicate the motor wattage. But let's assume it's around 1000W, so might draw 100A or so. On this basis, your breakers are underspecified. I'd suggest replacing one and removing the other. With 50sqmm cable, you're unlikely to have an excessive volt drop over only 8 metres.

 

[adwuk]

There is a chap on 01418874122 who used to work for Simpson Lawrence and now sells spares who might be able to advise you.

Thanks for the phone number. Very helpful. Apparently the motor is an old Lucas motor, which draws around 100W when lifting 100kg, and the stall current is around 400W. So the 40 amp breakers are correct - however I only need one of them, and I need to make sure that it is a thermal breaker, which allows short periods (read milliseconds) of very high current.

Other than that, the recommendation was to get the motor rewound, and then it will be good for another 40 years. Need to find a local rewinding service now then!

 

[pvb]

Apparently the motor is an old Lucas motor, which draws around 100W when lifting 100kg,

100W? Sounds incredibly low.

 

[adwuk]

That's what I thought, but apparently it is correct. I guess the WORM gearing means that a lower power motor is ok.

 

[adwuk]

So after some testing with a multimeter, voltage at the battery with the windlass running was 12.25v and at the windlass end 11.30v. This was with the windlass running but not lifting any weight. The circuit breaker tripped after about 15 seconds. The at rest voltage for the batteries was around 12.8v. So I work out that about 1v is being lost in the cable, but why would the windlass motor be drawing over 40amps when simply free wheeling. This is around 480watts!

 

[pvb]

So after some testing with a multimeter, voltage at the battery with the windlass running was 12.25v and at the windlass end 11.30v. This was with the windlass running but not lifting any weight. The circuit breaker tripped after about 15 seconds. The at rest voltage for the batteries was around 12.8v. So I work out that about 1v is being lost in the cable, but why would the windlass motor be drawing over 40amps when simply free wheeling. This is around 480watts!

If you're experiencing a 1.0v drop over 16 metres of 50mm2 cable, the current flowing is much more than 40A - nearer to 100A in fact.

Has this windlass ever worked properly? You don't say whether you've recently acquired the boat or not.

I'm still surprised that a windlass like yours only has a 100W motor; some windscreen wiper motors use close to that.

 

[adwuk]

I've had the boat just over a year, and no, the windlass has never worked properly. Over the winter I removed it, stripped it down and cleaned all the terminals. When I removed the motor there was no plate that indicated wattage, model number etc. The installed circuit breakers were 40 amps, which I replaced like for like, thinking that they may have been the cause. I think you are right though - although I have no way of testing the current, it does seem that for whatever reason, the motor is drawing something like 100 amps. Anyway, the windlass has been removed again (I nearly dropped it over the side ) and will be taking a trip to the local rewinding service tomorrow morning.

 

[TSB240]

I've had the boat just over a year, and no, the windlass has never worked properly. Over the winter I removed it, stripped it down and cleaned all the terminals. When I removed the motor there was no plate that indicated wattage, model number etc. The installed circuit breakers were 40 amps, which I replaced like for like, thinking that they may have been the cause. I think you are right though - although I have no way of testing the current, it does seem that for whatever reason, the motor is drawing something like 100 amps. Anyway, the windlass has been removed again (I nearly dropped it over the side ) and will be taking a trip to the local rewinding service tomorrow morning.

I may have come too late to this thread.

Our business is to specify and replace MCB's or breakers in new control panels for all types of motors single phase three phase or DC.

In our experience if a breaker has been tripped repeatedly (just a couple of times is sufficient) it should be thrown away as if you had a fuse fitted and blown it.

They are no longer operating to their design specification and will trip at much lower current settings than when new.

I am sorry if you are going to the expense of rewinding or refurbishing without trying ANOTHER replacement breaker first.

The chinese imported Chint brand are supposedly made from the old Telemecanique tooling. Cheap as chips but keep a spare . I can get them for a tenth of the price of a more well known brands! The quaility apears to be standing the test of time but I only use them with my "budget " customers....

Steve

 

[Billjratt]

I had one of these on my last boat. It also had a double breaker system although only one ever tripped. My main issue to begin with was belt breakage and jamming due to dirt build-up in the cogs of the pulleys. Once that was cleaned and the push switch repaired, it went fine on the original (1972) wiring and breakers. The battery was over 30 feet away from the windlass and the cables were not overlarge from memory.

 

[adwuk]

Well the thing is already at Anstee & Ware in Stonehouse, who assure me that if there is a problem with the motor, they can sort it. Point taken on the circuit breaker. The ones I have been using are these: http://www.force4.co.uk/carling-switch-40amp-circuit-breaker.html#.V1Wdu5MrKi4
If 40 amps is confirmed as what it needs (that is one of the questions I have asked), I will go and buy another two (both of the ones I have must have tripped more than a few times).

 

[pvb]

If 40 amps is confirmed as what it needs (that is one of the questions I have asked), I will go and buy another two

You only need one breaker in the circuit.

 

[davidpbo]

I have very simple low current electrics on my boat until now. I have installed a 9.9 Electric Start outbboard, as the cable is single walled (think admitedly) about 2m long and runs through 2 lockers I feel best practice is to fuse it. I will probably work to the gauge of the cable and maybe try 30 amp fusing to start with. The O.P's mention of two fuses one in the +Ve and one in the -ve made me think that is what I should do, although I probably won't as it is a bit OTT. for my installation and many consider a fuse unecessary.

I would imagine the winch is switched at the winch end of the cable either directly or indirectly by solenoid/relay and that the other end of the cable is pretty much connected to the battery directly. Effectively there are 2 live cables in this type of installation. One fuse would protect the circuit when motor is in use but it would not protect both cables when the switch is open.

Fusing the +ve only in a vehicle where -ve is now normally through the chassis is fine, but on a boat where +ve and -ve are run LIVE through 2 cores of large single walled cable a relatively long way through various bulkheads, lockers etc. fusing both would seem to me to me to be best practice although again possibly a little over the top as the likelihood of the negative cable getting damaged in such a way as to short against a different cable's positive is fairly low but a manufacturer has to do what they can to minimise ANY risk.

 

[pagoda]

I had one of these on my last boat. It also had a double breaker system although only one ever tripped. My main issue to begin with was belt breakage and jamming due to dirt build-up in the cogs of the pulleys. Once that was cleaned and the push switch repaired, it went fine on the original (1972) wiring and breakers. The battery was over 30 feet away from the windlass and the cables were not overlarge from memory.

SL windlasses - due to gearing, do not pull as many amps as many more modern devices. So voltage drop is less critical. Stripping and cleaning followed by new breakers (if necessary) should have you fixed for years.

 

[adwuk]

So the motor has been given a clean bill of health, after some new brushes and cleanup. I have also treated myself to a DC capable clamp meter, which shows that the windlass is drawing about 38-40 amps when free wheeling, and up to 50 amps when I try and slow the capstan with my hands. Anyway, that explains why the 40 amp breakers were tripping! I have an 80 amp breaker which I can use, but is that too much?

 

[TSB240]

50 amp will probably still have nuisance trips even with a D rated MCB. 63 amp is usually the next size up but I would suggest a C rated MCB as this will trip earlier than a D and give a bit more protection than your 80amp which seems a bit large given your measured current....

If you can wait until I am back at work I can see what we have left over in our stores!

 

[adwuk]

I put the 80 amp breaker in, and sure enough it didn't trip when pulling in 30m of chain and breaking a 20kg spade out of the sand. Unfortunately, as there were only two of us, I couldn't also measure the current used. The windlass did slow to a crawl at the breakout, which I guess is the point where it will use most power. When we connected the windlass up at first we did do some tests and the highest current we saw used was when the motor starts, and the max measurement was just over 61 amps. Is the start current going to be similar to the stall current?

And thanks for the offer TSB. What is the differenc between C and D ratings?

Anyway, a very happy camper as it was the last thing to get working after buying the boat last year.

 

[TSB240]

I put the 80 amp breaker in, and sure enough it didn't trip when pulling in 30m of chain and breaking a 20kg spade out of the sand. Unfortunately, as there were only two of us, I couldn't also measure the current used. The windlass did slow to a crawl at the breakout, which I guess is the point where it will use most power. When we connected the windlass up at first we did do some tests and the highest current we saw used was when the motor starts, and the max measurement was just over 61 amps. Is the start current going to be similar to the stall current?

And thanks for the offer TSB. What is the differenc between C and D ratings?

Anyway, a very happy camper as it was the last thing to get working after buying the boat last year.

Type B - trips between 3 and 5 time full load current

Type C - trips between 5 and 10 times full load current

Type D - trips between 10 and 20 times full load current

http://www.protekuk.co.uk/10ka-mcbs.pdf

Sorry the old stock has been sold off!

Did you check to see if your cables got hot?

We use a "heat gun" to detect for overheating cables and bad contacts on screw connections etc especially on older installations..

A great way of persuading customers that a new machine control panel would be better than a replacement factory after a fire!


Steve

 

[adwuk]

Thanks for the explanation Steve, and for checking your old stock. I'll stick with the 80 amp for the moment until I have enough people on the boat to measure current while retrieving the anchor. I haven't checked the cables for heat yet either, so will make sure that to do that soon. I have replaced all of the cable terminals in the last year, and as the cable is over-specified I can't think it will be a problem.