Rewiring a centaur

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Swanrad2

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Hi,

I have started to plan 2017 winter refit and its rewiring. I know nothing, but this is how we learn. Any suggestions as to where to start? Maybe a good YouTube link or a book for the absolute beginner. Before anyone panics my (aged) father in law is a sparky and although I can't ask him to crawl around inside lockers, I can get him to make sure I'm not going to kill anyone!

Cheers.

S
 
Can't you just follow and replace old cabling with new, or is it a complete new layout? Follow all the original circuits and extend where necc? Just a suggestion, probably useless though. It's just that when I rewired my snapdragon, I used all the same circuits with new cabling and extended where necc. to fit in with my plans.
 
Swanrad2 said:
Hi,

I have started to plan 2017 winter refit and its rewiring. I know nothing, but this is how we learn. Any suggestions as to where to start? Maybe a good YouTube link or a book for the absolute beginner. Before anyone panics my (aged) father in law is a sparky and although I can't ask him to crawl around inside lockers, I can get him to make sure I'm not going to kill anyone!

Cheers.

S
Click to expand...

One thing you may have to get across to FiL is the need for the wiring of 12 volt circuits to be over rated, compared with mains wiring, to avoid unacceptable volts drop if he has no experience of boat wiring.

Another book which may be worth considering is "Essential Boat Electrics" by Pat Manley https://www.amazon.co.uk/Essential-...qid=1497378503&sr=1-2&keywords=boat+electrics

The ultimate "Bible" is of course Nigel Calder's book, https://www.amazon.co.uk/Boatowners...qid=1497379029&sr=1-3&keywords=boat+electrics

You should really follow the latest editions of the standards

"EN ISO 10133: Small craft - Electrical systems - Extra-low-voltage d.c. installations" , for the 12 volt wiring

and "EN ISO 13297: Small craft - Electrical systems - Alternating current installations", for the shorepower wiring, assuming you are installing a shorepower system
 
I rewired Snark with untinned cable. If you do this, leave long tails at connection points to allow you to cut back to good core cable from time to time. +1 on "fat" core cables to reduce voltage drop. I'd use trips instead of fuses if i did it again and ensure the "consumer unit" was easily accessible. I have three fuse "boxes" hidden in various places which seemed sensible when I did it (keeping them dry and away from spray) but when a fuse "blows" replacing it is a bigger headache than it needs to be. Also do not use auto fuses of the blade variety. I have had them corrode to the fuse holder. If nothing else is to hand, smear all contact surfaces with vaseline.
 
I am not an electrician but employ them and work with them often. The problem is that often they believe that because they know all about one aspect of their craft that they are experts in other areas. My favorite industrial electrician who wires up complex automation and robotics systems for me is an exception: He admits he doesn't know very much about wiring houses or boats.
My own boat when i bought by it had been rewired by the previous owners mate who was "an auto electrician, so he knew what he was doing!"
Nope! a boat full of un-tinned wire of small gauge and inappropriate instruments and fittings. It was Carp!
Tinned wire, and marine rated fittings. Settle for no less.
Over spec the wire diameters.
Crimp or solder? There are many threads passionately arguing the pros and cons. Whatever you choose, do it to the best standard you can.
Having rewired my own 26 ft boat i can say that the cost of materials to do it right will be more, but actually not too much and also that there is a lot more complexity to it than i for one anticipated!
Its only a sailing boat after all so how complicated can it be?
Well then, circuits for navigation lights, anchor lights, cabin lights(split so a single fuse failure doesn't kill all the lights in the boat!), Instruments, VHF, 12 Volt power outlets, entertainments system, water pump, bilge pump.
Add in engine charging circuit, solar charging and possibly split battery banks.

None of its really difficult, but its worth having a plan before you start.
Good luck
 
Swanrad2 said:
Hi,

I have started to plan 2017 winter refit and its rewiring. I know nothing, but this is how we learn. Any suggestions as to where to start? Maybe a good YouTube link or a book for the absolute beginner. Before anyone panics my (aged) father in law is a sparky and although I can't ask him to crawl around inside lockers, I can get him to make sure I'm not going to kill anyone!

Cheers.

S
Click to expand...

Cracked the back of a "start from scratch" installation on my H20 last winter... purely f.w.i.w., as almost certainly someone will point out the shortcomings of something or other I've done (;)), the story is here...

http://hurley20sparrow.blogspot.sk/search/label/12v

..start at the bottom/first post and work up/back...
 
Using tinned wire throughout is a good aim. Making sure each circuit is readily identifiable from its colour is also a good aim. It's pretty near impossible to achieve both unless you have a simple installation that doesn't use many colours. Try to use tinned anywhere that the wiring is going to be exposed to damp.
 
One thing that I found with my Centaur was that over the years the wiring had been modified to the point of confusion! I would follow a wire from the switch or fuse box to find that it had been cut off and left to dangle! I must confess that I got a marine electrician to tidy up some of it and a very nice job he made of it! Good luck!
 
Humblebee said:
I found this website very helpful, see link below.
Best book I've come across is Miner Brotherton The 12V Bible.
For specific advice re the Centaur, try the Westerly Owners' Association. Plenty of advice and experience there to draw on.

http://www.tb-training.co.uk/index.htm
Click to expand...

Yep, Miner Brotherton every time - The 12V Bible doesn't look as exciting as some of the other colour illustrated versions, but they are there to entertain, whereas the 'Bible' tells you exactly how to do it and in language the amateur understands.
Good luck.
 
lpdsn said:
Making sure each circuit is readily identifiable from its colour is also a good aim.
Click to expand...

I would not attempt that. Too many colours needed on anything but the simplest boat, and a very inefficient way of buying wire as you'll need lots of cut lengths instead of a reel or two - and you'll end up with lots of offcuts.

Buy a reel of 1.5mm2 tinned flat twin thin-wall to use for nearly everything, and set it up on a stick somewhere convenient inside the boat to pull off lengths as needed. Buy cut lengths for the odd bit of heavier wiring or three-core that might be needed. Label it with either numbers referenced to a list (which you'd also need for colours) or directly with names. Ideal system is printable heatshrink, but you can also use printed label tape (e.g. Brother) with clear heatshrink over, or just sharpie on tape flags for a messy but cheap job.

Don't forget that wiring does take up an appreciable amount of space and you do need to consider the physical layout as well as the electrical connections.

Pete
 
lpdsn said:
If I ever buy another boat I'll thoroughly check out the electrics. And if it's all black and red I suspect I'll walk away.
Click to expand...

Seems a silly reason to walk away from an otherwise good boat. Especially if the wiring is well-made, neatly installed, and accurately labelled, but you just don't like the colour.

Or let's say you do find a boat with rainbow wiring - what are the three purple wires connected to?

What about a house wired in all blue and brown?

Pete
 
My comments re wiring might be conflicting with others advice. However I would use the heaviest tinned wire you can reasonably use and afford. Heavy means longer life in corrosive atmosphere and resistant to physical damage.
This will mean that just a few fuses indeed just one can protect all your domestic and nav gear. The fuse or breaker must be of a lower current rating than the wire but more than the total current drain. This will not be a problem if you go for LED lights.
I would go for an engine start battery and completely separate wiring for the engine circuits. The engine instrument wiring may be OK. Fit an isolator switch (high current) for the engine battery. All assuming you have an inboard engine.
Fit a separate deep cycle battery for domestic and navigation gear and lights. Wired to a switch board with fuse/ circuit breaker. Or as many as you think you need. As I said one should do. Because actually failure of circuits and subsequent fuse blow is very rare and while it will disable all your nav and domestic electrics I reckon this would not be a disaster.
You need an isolation switch for domestic battery circuits.
You need a way of charging the domestic battery. You can have a paralleling switch for charging also good for jump starting the engine off the domestic battery in an emergency. But better is a Voltage sensing relay that will operate when engine is charging to connect domestic battery for charge.
I would suggest an amp meter for checking charge into domestic battery and a volt meter built into your switch board which you can make your self. All very simple really good luck olewill
 
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