Boat (River/canal) wiring - Re-wiring advice needed

[SparkyChick]

Hi all,

Long story short, I'm in the process of helping a friend get a boat ready for sale. It was her Mum's, she's no longer with us, and is in need of an electrical refit because too many people with zero clue have cobbled in new stuff.

In general, I'm happy with my plan but I'd just like a bit of feedback from people more experienced than I in this field.

The installation, aside from the ignition/charge circuit, is quite limited. It has running lights, an upfront head light, a car stereo, cabin lights, water pump and some power outlets. The power outlets are some old fashioned square plug/socket arrangement, never seen anything like it before, but I'm going to install cigarette lighter sockets (3 off) and USB outlets (2 off). Cabin lights will be LED, running lights and headlamp LED also.

It also has a 240v shore hookup.

My thinking is that everything will be a radial, except the power sockets. I'd rather not spend loads of money on varying sizes of cable, so I'm looking at 1.5mm Tinned Copper (rated at 21A) for nearly all the wiring, with the power circuit connected in a ring so effectively having a 42A capability. It will be fused down to 20A but I don't like the idea of running the cable just under it's rated maximum. The cable is this:-

Single Core Tinned Thin Wall Cable - 1.5mm² 21A - http://www.12voltplanet.co.uk/single-core-tinned-thin-wall-cable-1-5mm-21a.html

My plan is to build a custom wiring loom and wrap it in fabric tape, pull it into place and terminate.

Currently the water pump is directly switched by the sink taps, my feeling is I'm going to add a drive relay so the taps switch the relay. I have no idea of the spec of the taps or their usual rated current and I have no idea on the rating of the current water pump, I'm just being cautious.

Can anyone see any problems with what I've suggested so far?

It has a single 12v battery, for starting and powering the equipment. This is charged by the engine when it is running. I'd like to add a charge/power option so that when it is connected to the shore line, the battery is being charged or that unit can power some equipment (like cabin lights, power outlets and stereo). Does anyone have any suggestions for the charger that don't cost the earth? I'm looking at using a Rovert RE25A12PS.

I have no idea if there are any special regulations I should follow aside from things that may be appropriate in BS 7671, so any advice would be greatly appreciated.

If you need more information, don't hesitate to ask and I'll do my best to answer.

Thanks

Christina

 

[westward10]

Sounds interesting I like doing something a bit different but not done anything on a boat. I have done some work for Midland Chandlers who have branches dotted about on the waterways but not sure if there is one in your neck of the woods, they stock a whole plethora of boat bits including electrics.

 

[Spoon]

First of all I don't know a lot about marine wiring. I'm sure someone will correct me if I put anything wrong.

but I don't like the idea of running the cable just under it's rated maximum.

If the cable is rated at 21A then I don't see a problem with sticking 20A through it.
With regards to the 21A, it doesn't say what installation method. I presume this still counts for your job.

My plan is to build a custom wiring loom and wrap it in fabric tape,

Would this not affect the rating of the cable? EG like cables going through insulation material...

 

[Wilko]

My inclination is to over spec the cable, i.e. 2.5mm. Also I'd not do ring, too many variables for a boat

Edit : don't forget to ventilate all spaces esp. anywhere with fuel ...

 

[SparkyChick]

The difficulty with compensating for the tape is I can't find anything appropriate in BS 7671. But grouping could be an issue, there will be one part of the loom that has 4 circuits in it which results in a Cg of 0.65, so the 21A becomes 13.65A, but for the majority, Cg is 0.7. That's a bit too close for my liking.

If I switch up a size and go for 2.5mm rated at 29A (which to be fair is more like the size I see all over my car), it's 18.85A and 20.3A respectively. Most circuits will be fused at around 5A or 10A. I can't say anything about the water pump because I have no information on it, it's just there, but I'd take a punt on it being 0.75mm cable (it's wired in some twin core mains flex).

I think I'm going to go for the 2.5mm, for the bulk of it and do the power outlets in 4mm without the ring to err on the side of caution, but having just looked, there is an electrical standard for small craft. I'm allowed a 10% voltage drop (2.5mm complies easily up to 15A and 5m - it's not very long), but it even stipulates maximum battery movement, somehow I don't think the battery cage I've built complies

The annoying thing is, most of what is there is original, but it's just chucked in. When I took a panel off to get at the existing wiring, it revealed a multi-colour patchwork of what looks like old doors that make up the cabin framing! The cables run down from the switch panel through blocks of wood, so whatever goes back in is going to be a far better solution not least because at present the wiring is unprotected single cores slung behind cupboards and such.

The battery and the fuel tank are outside, although the seals between the battery compartment and the cabin aren't great, so they'll be replaced.

Thanks for suggestion @westward10 will have a look on-line and see if they have a local branch.

I'm quite looking forward to getting it done. Just need to hope that the outboard motor I rebuilt (it dropped a valve head off the stem) runs smoothly once I've backed the cam followers off a little. It ticks over lovely even with a rewound alternator coil (embarrassingly, undoing the flywheel nut, screwed a bolt through the wheel for leverage, it moved and I sliced the coil in half with it) but if you give it any throttle, it starts to miss and backfire. Last time I adjusted cam followers, I had my Dad around and being a mechanical engineer he was far more adept with feeler gauges then me. I think I've been a little over eager and not given them enough clearance resulting in premature opening and delayed closing.

Anyhow, thanks for the advice so far fella's much appreciated.

 

[Wilko]

It ticks over lovely ... but if you give it any throttle, it starts to miss and backfire. Last time I adjusted cam followers, I had my Dad around and being a mechanical engineer he was far more adept with feeler gauges then me. I think I've been a little over eager and not given them enough clearance resulting in premature opening and delayed closing.

Hi - not being able to hear the motor, but my guess is this is either timing or fuelling (too lean?). Proper backfire (that activates one's ptsd) most likely from ignition timing. Popping more likely from fuelling.

 

[SparkyChick]

The timing is fixed, by a blob of steel welded to the flywheel. There's absolutely no adjustment that I can see. Even the pick up is fixed. There is so little adjustment on the engine as a whole, but then it's hardly surprising when they have service intervals measured in 25 hour increments. That would just about get me from Goytre Wharf to Brecon on a leisurely 5 day run. Have it serviced, chug back, have it serviced again. It's crazy, but it is and old engine.

I am a little concerned because it's now a combination of two engine revisions. Based on a part number assessment, the head and block changed (along with some of the parts obviously) to address some cooling and oil pathway issues. Things like the timing belt, alternator, ignition etc. are all the same for both revisions as best as I can tell. It's a bit of a frankensteins motor though

The explosive exhaust and kind of chuffing from the inlet gets progressively worse as the engine speeds up which makes me think it's the valve clearances. I thought at the time I was being a bit over eager with it and I should have backed the followers off slightly. Will soon find out.

Got a busy few weeks on it, fibre glassing needed on the hull, roof linings got to come out for some repairs, got to make a new step for the back, possibly a new window frame for the front and somehow got to get it off it's trailer so I can repair the trailer runners and paint the bottom (if it doesn't scrub up nice)

 

[PEG]

Hi,if it is on a trailer,i'm guessing it is not a big un' - What engine is it?

I have recently been doggin' up an old river cruiser,and it sounds like a similar job.

 

[SparkyChick]

It's a Wilderness Water Rat Gypsy, just over 5m long I think. Designed as a trail boat, supposed to be easy to take on and off the trailer. But it's not so easy to take out of the water, can hardly see the trailer once it's on the ramp. Had to don my waders just to make sure it was lined up properly. But the runners on the trailer were supposed to have been replaced as they were rotten. It's now off one of the runners because it's given way so am a bit concerned about the possibility of a bolt having gone through the bottom.

Someone's told us we can stack it on bales but it's pretty low and I'm going to need to get under it to give it a good inspection. It needs some minor work on the hull, mainly on the corners where it's bumped the banks of the Mon and Brecon. It's a fibreglass hull so repairs are going to be fairly straightforward. Although someone has already had a go with plastic padding. Overall, it's in fairly good nick, but there are some bigger issues with it like the fact the upper half of the cabin sits on top of a rib around the top of the hull and it's pulling away from the rib. I suspect there is wood encapsulated in the glass fibre that's gone rotten and the screws are just pulling out, similar thing on one of the roof bars. Could be a problem. Bit concerned about the transom board for the same reason. Had to replace the rail at the back, which was fun, cutting and welding steel stock

Some of the windows are just fixed in with rubber window beading, possibly shaped specifically, but they aren't well fitted so it's got a bit of a mildew issue at the front in the cabin and the lining carpet has suffered as a result.

The engine is a Yamaha F9.9A (can't remember exactly, but it is electric start, remote throttle/direction with a tiller style handle). I think the bulk of it is a 1987 vintage, I think the head and block are about 1990 vintage, and the gearbox, god knows But all the seals, gaskets etc. have been replaced. It does have an issue with the oil warning light as in I can't decide if the light/sensor itself isn't working or it's not getting up to pressure.

We've been told we could sell as is for a reasonable sum, but were advised that with a bit of TLC the price would nearly double. Trying to get it ready for the start of boating season, as we think it will sell quickly.

 

[PEG]

Hi,i hope that old fibre-glass hull is not suffering from the old osmosis curse...

Did you have a cam belt issue,to lose that valve head? The valve clearances will be tight on that,probably 5-10 thou,old money,so it could be chuffing due to being tight.

It could also be a bent valve,which sometimes only shows during grinding-in.

Always remember that a boat is just a boat shaped hole,in the water,to shovel money in to...

And the two best days of a boat owners life?

The day that you got it....and the day that you sold it

 

[SparkyChick]

I'm not familiar with the osmosis curse, but I think I can guess because I have been concerned about water in the fibre, but sounds like you might have some useful info

The head of the valve sheared off where it joins the stem. Looks like a fatigue crack. It didn't get much use and she was 5 days in running up to Brecon, warming it up and it just stopped with a thump. Couldn't turn it over as the head of the valve had just come off and fallen into the cylinder. Unfortunately due to age, spares were difficult and the valve head had smashed the spark plug port a little. I managed to pick up another block/head from a chap who's workshop had been flooded out the last time the Thames had a moment. But it was lacking some parts, so both units got stripped down and rebuilt as one. As I mentioned, there were some significant changes to cooling and oil pathways in the newer head/block, looks like to keep temperatures down in the head by improving cooling, and it had a much improved oil filter. I reground the valves and that went alright, no sticking, so fingers crossed, when I tinker with the clearances a little it will improve things.

As for it being a money pit, tell me about it. We tried to put her off buying it, but she didn't listen and it has cost a lot of money. Don't get me wrong, part of me would like her daughter to keep it, but being realistic we just wouldn't use it enough to warrant the costs or time commitment.

 

[PEG]

Hi,I have worked on Yamaha stuff,since childhood and a fatigue crack would be rare, but not unheard of,but usually after a slight bending incident. A possible cause,is if stood for a length of time,in an open position,is the exposed part rusts up and the piston has to "help" closing it,as it runs tight.

A quick compression test on both cylinders,would show up any valve problems.

I have had this twice last year,where one friend got left a boat,and felt beholden to keep and use- it was a disaster.

The second one,a pal still has,it was a very expensive,wooden cruiser,in it's day,teak,mahogany,brass....

I got it's Perkins diesel running (8 years after last run),the boat itself is a wet,rotting nightmare,not suitable for a viking funeral (wouldn't burn) and there is a growing angry mob of wealthy pensioners,pretending to want to buy it,for the mooring...

I would endeavour to keep the electrics,as simple as possible,LED's everywhere,small charger/monitor for top up when on shore power,no need for 12V psu as you won't have that much off the single battery.

The Yamaha charge output will be minimal,but will put back enough. Maybe a small inverter for some short term 240V use.

Hopefully,in time,she will swap it for a race-horse or F1 racing car....and she can save some money

 

[SparkyChick]

The previous owner (my friends Mum) has left us and we're under the instruction of her will to sell it, so no chance of acquiring another money pit, thankfully

She very rarely took it out, so what you've said about being left standing could make sense.

The electrics side of things, I'm thinking pretty much exactly what you've said. The biggest question I have (apart from the cable sizing discussed earlier in the thread) is any recommendations for a charger, I'm looking at a Rovert 20A unit that can function as a PSU if needed. I did consider an inverter, but we're trying to keep costs down to an absolute minimum.

Thanks for the info

 

[HandySparks]

The electrics side of things, I'm thinking pretty much exactly what you've said. The biggest question I have ...is any recommendations for a charger, I'm looking at a Rovert 20A unit that can function as a PSU if needed.

I'm not a boatie, but why would you need a charger that can act as a PSU, supplying loads directly? Surely it would be easiest just to run the DC loads off the battery full time and fit a good sized charger to top it up when power's available?

 

[PEG]

Hi,the thinking in the boat world,is to use the same supply for the lighting,so 12V on the waves,and the same,via PSU/charger when on hook-up.

There are many units now,which can monitor and supply 12V loads,whilst still maintaining active charge control,of the batteries.
In the OP's instance,i would not bother getting too techy,with a cheap charger/conditioner being wired full time.
Just ensure ventilation requirements,fusing,etc,is attended to.

If the engine has pull start capability,it won't matter so much,when lounge-lizard teenager laptop types,flatten the battery,playing Candycrush,instead of loading tippers with a wheelbarrow,like i did,at that age