Re-wiring - a psychological hurdle

[sarabande]

It's about time that my wiring was rationalised and replaced. I want to know where all the watts and coulombs go, and that the fuses, RCDs, etc all work properly.

The previous owner wired in all sorts of extras over time, and I want to take out all the physical computer wiring and replace all the incandescent bulbs and lights with LEDs, and renew all the instrumentation (mainly Autonnics), and renew the instrument panel, and replace the shore power units and all the 13 amp sockets...

OK, so I know Ohm's law, and have copies of the 12v Handbook, Boat Electrics, Energy Unlimited, etc, but...

WHERE do I start ?


There's no existing wiring diagram; I do not have a list of electrical kit and its ratings; I am not sure if I should plan to install extra (unused) circuits for future use; and above all I have never done a 24/12v rewire before.

Is there any training course the Forum can, in its collective experience, recommend ?

or

Do I buy a good boat electrician's time for a day to show me how to plan the wiring, run cabling, make connections, install kit, etc ?

Finally (just in case the insurance co is listening in (/forums/images/graemlins/grin.gif) Hello Pataneous, or Newton or St Margarets or GJW or Bishop), I want to have the new electrics checked out and "approved". Who does this please ?

 

[damo]

"Do I buy a good boat electrician's time for a day to show me how to plan the wiring, run cabling, make connections, install kit, etc ?"

Sounds like a sensible approach /forums/images/graemlins/smile.gif

The whole thing seems very daunting to start with, but with the books (don't forget Calder) I did the whole lot myself: 2 batt banks, split charging, smart regulator, new distribution panel, inverter etc. I made a distributed system ie a single run of bigger cable to a fuse box in eg the forecabin, then smaller stuff to the lights. It saves on wire, and it is easier to thread

If there are 2 things I would emphasise they are

1) Run extra conduits and cables and mouse lines for future expansion, while you have lockers and linings etc exposed.

2) Make the distribution panel twice as big as you think, with spare busbars. (The wiring seems to expand as you fit it!)

3) Run extra conduits and wires etc (I've used mine up already and wished I had fitted more)

 

[oakleyb]

I've recently rewired my boat, i'm no expert but used the following approach.
1, Made new fuse panel - used hinged box that came with oil paints from argos
2, Made a list off all electrical devices, and started to rewire each in turn
3, utilised existing wiring for lights etc

Overall very pleased with the project and now have the satisfaction of knowing where all wires go etc

 

[shmoo]

May I add a couple of rules of thumb (or, in the case of a duffer like myself, rule of thumbs)

1) Never join wires
2) (If Rule One can't be followed) Never join wires in out of the way places.

 

[simonfraser]

gas solder & shrink wrap all the joins, especially the out of the way ones.

set up a small temporary circuit to power the essentials before you rip out the existing circuits, than you can still go sailing and it doesn't have to be finished asap.

label at least the main wires as you go.

i did mine this winter, well worth the effort, now i know it is sound and i understand it.

run extra nmea / seatalk or whatever you think you may use, wires too.

 

[savageseadog]

Where to start? Rip the lot out.
Make a note of anything out of the ordinary.

 

[PembrokeshirePromise]

Also - suggest once you have your head round what you want and what the various bits do yoo could do worse than look at:

http://www.power-store.com/index.asp

They sell some nice integrated switches, VSRs etc - which I'm sure isn't the cheapest way to go - but certainly can make installation of some of teh bits easier / tidier. They are also very helpful if you need to talk things over.

No connection etc etc

 

[Salty John]

Start with a schematic wiring diagram. Next, make an installation drawing. These don't have to things of great beauty - just so you can understand them.
Note any wire runs that you wish to retain and show them on your drawing.
Make a schedule of each new wire run noting the wire size, colour, type of termination, marking etc.
Build or acquire any new panels, circuit breakers, switches, etc.
Go for it.
There is a modern trend away from soldered joints based on quite convincing evidence that the soldering consolidates the individual strands of stranded wire and causes it to behave like solid wire. These wires break at the joint through metal fatigue.
Get yourself a good quality ratchet crimper - Ancor makes one - and use good quality marine terminals, cover them with adhesive coated shrink tube.
Have fun, the end result can be very satisfying.

 

[pmyatt]

Am just coming to the end of a lengthy refit, including all wiring, pumps, instruments, switches and fittings. Don't start just by ripping out everything that exists at the moment - that's the mistake I made. To start I would suggest getting some A3 paper and doing an outline of the boat with all bulkheads. Make a list of all the facilities you are going to fit and then mark them on the diagram - from there it is relatively easy to plan wiring. Once the wiring is planned, take measurements and tot-up how much you need of each type of cable - old fittings are usually a good guide to the gauge needed. At this point remove all removable panels which conceal wiring ducts, also, remove all flooring, doors, cushions and berth bases if you want to make life even easier - but keep a place to sit down - you will need it when it all gets too much of a puzzle! You are now at the point where you can remove equipment, but, label each piece of wire with its old function; a hand-held label machine is a god-send here. Once you are that this point you can start pulling out the old wire and using it to pull through all the messenger lines you are going to need; add a few extra as has been mentioned already. From then on start pulling through the new wires, labeling each end as you go - leave enough slack at each end to connect to whatever equipment you are fitting. It also helps to start at each end of the boat and work towards the instrument panel.

 

[Tranona]

Support talking to Merlin (powerstore) as they will plan your system for you and provide all the parts including a wiring diagram. Probably not the cheapest but saves a lot of hassle and you get top quality gear. You will still save over getting somebody to do it for you as there is a lot of labour involved in fitting.

As usual, happy customer recommendation

 

[VicS]

[ QUOTE ]
WHERE do I start

[/ QUOTE ] Rip out all the stuff that has been added and get back to the original which hopefully will not be too bad. If thats no good then that will have to come out as well.
Then build up with good kit, decently routed and installed cables from there.

 

[sailinglegend420]

I would recommend that you use proper marine grade tinned wire that will last a long time. It will cost a lot more, but you don't want to be re-doing it all again in 5 years time.

Merlin/Powerstore are the best and can supply everything - including good advice.

You'll also need a very large crimping tool for battery and starter/alternator cables. Can be hired for about £10/day - but probably cheaper to buy one - you can then hire it out to others.

It's a big undertaking if you are not elecrically minded, but there's a lot of manual work that is not too difficult. Do find a friendly electrician you can hire by the hour when you need help.

 

[pvb]

Couple more random thoughts. Use circuit breakers, not fuses, on your main switchboard. Separate your interior lighting into 2 or 3 separate circuits, so that if one circuit trips you still have light available. Don't forget to add a MegaFuse right next to the domestic battery bank.

 

[djh1962]

Hi ,
some good advice, as this is sort of my discipline I did it slightly differently. Moved all electrics to new panel I built for the job.

Planning is everything -
See attached, draw/design for what you want for your boat.
Plan some redundancy & service loops i.e dont make everything tight as possible.
Mark up all existing wiring as best you can for reference.
Rip out in managable chunks and replace and test.
I found 7 core trailer cable ideal, with an 2mm sqr return perfect (it is designed for 12Volt use on cars etc).
Dont joint cables unless you have too, terminate in a IP proof box of some description , which is accessible and spray with WD40 annually, will last for decades!

Hope this helps
Tight sheets

DJH /forums/images/graemlins/laugh.gif

 

[lw395]

Couple of points:
A decent auto electrical place will do any heavy crimping for a few quid, around Portsmouth Furneaux are v helpful.
Not sure about the 'breakers not fuses' post, I don't know that I trust breakers as they are going to sit in a slightly salt atmosphere for 10 years and never get tested- will they be stuck on when needed?
I would use them for anything that has an overcurrent fault mode, like a motor that can stall, but backed up by a fuse that will protect the wiring.
If you have shore power then the RCD is a different matter, it's easy to test and an absolute must have imho.
The other thing is that to make a neat job of wiring, it takes up more space than you thought!
Cheers,

 

[peterb]

It's not always easy to make a neat job of naming all the cables. Draw a wiring diagram, number all the cables, then use the ring type numbered markers (eg ex-Maplins) to identify the cables. Much neater than Dymo tape, and you can pull the marked cable through conduit.

 

[ghostlymoron]

I recently had some re-wiring done - I took the easy way out and hired a professional.
Some thoughts on DJH wiring diagram.
There seems to be no way of charging the domestic battery from the alternator, is the solar panel sufficient when you are running the fridge?
I wouldn't recommend trailer multi-core, it is neat but the cable would need to be downrated over the equivalent single core and may not be large enough.
If charging both battery banks from the alternator, you need to include diodes or other gadget to avoid the possibility of flattening your 'engine start' battery.
I like the format of your wiring diagrams - what software did you use?

 

[pvb]

[ QUOTE ]
Not sure about the 'breakers not fuses' post, I don't know that I trust breakers as they are going to sit in a slightly salt atmosphere for 10 years and never get tested- will they be stuck on when needed?

[/ QUOTE ]The switch panel should be in a fairly sheltered position inside, so shouldn't be subject to excessive moisture. Good quality breakers (Blue Sea, etc) are extremely reliable over many years of use. If the switch panel is in an exposed position, a weatherproof panel must be used. Shorepower circuits typically use breakers too.

 

[bryeomans]

Having just done the job on my own 34ft sailing yacht here are a few thoughts:
Agree that best to sketch wiring diagram but do not be surprised if reality is slightly different. Write everything you do down on a wring list as you do it and redo the actual wiring diagram afterwards.

Estimate carefully - we needed over 300 metres of 16AWG alone and we still ran out twice in the middle of the job and had to wait for the mail order to arrive.

Thoroughly recommend Merlin Equipt - very helpful, vast product range and all of the kit we had was v.good indeed. They also supply connects in bulk and you will need lots more than you think! Buying 5 at a time from your local chandler not recommended.

haven't done the shore side power yet, but am considering getting that done by a pro. It is difficult to kill yourself with 12V (though it can be done) but 240V different matter.

It is a very long job indeed. An electrician for a day won't be much good to you(unless for 240V side?). It took us the best part of a couple of months working 3-4 days a week toget the job done.

Good LED lights are expensive (£100 per lamp for at least one type!!!), cheap ones susceptible to voltage surges and most do not give bright enough light - decorative but not effective. Red night lighting is about only sensible LED application I would suggest.

Worth getting good ratchet crimpers for connections , but shop around - I bought ours at Trago Mills for £14 - but equivalent near identical crimper from ANCOR priced at £60 plus!!! We did buy full on pro crimpers (£100+) for battery circuit connects - we were quoted £2 per crimp locally (we needed over 30 connects) and found no source prepared to hire them out. I like having the proper tools!

Buy a pair of good wire stripping pliers and an insulation stripper for larger cables.

Avoid chocolate box ("EU") connector strips like the plague- proper ring terminal blocks much better proposition

It is fun to do , very satisfying when complete and even more so when you have your first fault and know exactly where to look for the problem!

PS we did ours because the original (automotive type) wiring was over 30 years old, was becoming very badly corroded in places and the insulation had gone brittle. When the job began, we found short circuit burn throughs in wiring runs inside conduits. I wonder how many fires in older boats are caused by that sort of problem?

 

[pappaecho]

I did a complete rewire ona 25 year old boat 3 years ago.
I used meter tail cable to provide a complete sub mains from Auxillary battery bank to master switch and thence onto the centre of the boat.
From there I got 24 volt lorry cable in 12 different colour bundles, all insulated in an outer sheath, which were run from the main area to each cabin in turn,and cockpit. All negative returns were returned to a large negative busbar, and the positives to switch or mcb banks on the console. I identified 24 separate circuits, largely for lights but equally for electronic gear, and a few reserves, which have miraculously been used up!
In addition I put two "marine quality cigar" points in the wheelhouse and main cabin and a third in the cockpit. They were total rubbish!
I replaced with red/black gold plated terminal system from Maplin, which take both banana plugs and spade connectors ( and at a pinch bare wires!) and these have been proved faultless and take twice the load as the cigar sockets which over heated on load ( Inflatable dinghy pump for example (-uses 12 amps)

Good luck