Jump to content

re wire


Guest SORREN

Recommended Posts

I think you will need to use flex not wire which has mutiple strands and will allow for movement after that 1.5mm 3 core for 240v lighing if any and 2.5mm 3 core for power outlets wired as a ring main or indiviual spurs with separate trips. 2.5mm heat resitent for imersion hater final conection. I would think any 2.5mm flex bought from b&Q etc would be stamped to the relevent british standard.Hope this helps

Regards Jonathan :Stinky

Link to comment
Share on other sites

Are we talking a complete 12v and 240v re cabling here? The major thing is to use cable (not wire, sorry for the pedantry) with as many strands as possible and to use fully tinned copper to reduce corrosion and high resistances and disintegration at terminals later in the installations life. There are calculations for making sure the system has the correct sizes for each unit requiring power. Get yourself a copy of the book “The12v bible†it will give you all the information you require in an easy to digest form.

Here’s a good site for the correct grade of supplies http://www.marineelectrics.co.uk/

Link to comment
Share on other sites

I can also recommend the 12v Bible For Boats - I bought one, started reading it and it found it not just informative but actually interesting. Unfortunately I lost it after just a few chapters! Mental note, buy another.

Having had first hand experience of what happens to standard autocable in a marine environment I would also back up David's suggestion of individually tinned cables. During my time owning Silver Dream more than once did I come across the joyous results of autocable and chock blocks. By the time I was looking at them much of the cable terminals had literally turned to dust - an annoying green dust for that matter (presumably copper oxide).

Link to comment
Share on other sites

Indeed Simon, it's not nice watching your stuff turn to dust before you eyes, usually when you need it to perform. It's a constant source of amazement to me that every broads chandler I’ve ever been into and asked for marine quality cable has offered auto cable and called it marine, good quality auto cable maybe in a couple of cases but still bare copper. Strip a tiny bit of insulation, if the strands are not silver it’s not fully tinned marine quality. It would be nice to think that nobody, but nobody would use anything less on a critical application but I have seen auto cable used on bilge pumps. :roll::roll:

The alternative is if you must use bare copper is regular thorough inspection of all terminals and replacement as needed, perhaps not so bad on a boat with very few systems. Adhesive lined heat shrink over the terminal crimp will help against moisture penetration but then it just hides the problem when it does occur. This is of course less of a problem on the rivers than in a true salt laden marine environment but the problem is still there, just not so quick to raise it’s head.

Link to comment
Share on other sites

Out of interest, any idea on how long a half decent copper cable might last (from new) on a river based cruiser? I realise there is a "how long is a piece of string" element to that so, for the sake of example, let's assume choc block terminals with a stretch of exposed cable going into it in away from actual water ingress for instance, in a head lining or roof lining, on the engine bay wall or something like that, but not actually somewhere that it would get wet like a bilge pump line might).

Link to comment
Share on other sites

You have answered your own question Simon, how long is a piece of string? but 5 to 25 years would be a realistic estimate. That said I’m sure there are examples out there with longer life if really well installed in a protected position. Even the quality of the copper is an issue in some cheaper cables. My view is that even in non critical applications a failure may affect other more critical areas of the overall installation and it's just another spoiling the ship for a hape'th of tar situation.

I don’t like stuff going tits up on a boat, it puts me off what I should be doing and in the wrong situation I might make a bad decision due to the distraction, lack of information or control failure caused by scrimping on the right bit of cabling.

Link to comment
Share on other sites

A big thank you to everyone,

i am about to strip out all the old wires on my first project and want to make sure i put all the right stuff back in, Any other advice on the electrical side of things would be recieved with gratitude.. :Stinky go baby go

Link to comment
Share on other sites

Is this corrosion caused by electrolysis as it occurs in the 12v wiring which is earthed to the engines etc through neutral, although most heat exchangers are copper and are fine with sacraficial anodes fitted. Or is it caused when saline carries a curent between live and neutral. I have had this problem but only in the bilge.

Jonathan

Link to comment
Share on other sites

Larger cable teminals (usually ring) above 6sq mm are difficult to obtain in fully tinned copper and expensive when you can. Screwfix have just begun to offer them in packs at a very good price up to 16 sq mm, also if you are doing any amount of work they offer the propper ratchet crimp tool for about £22.00. Just bought a selection and the tool for the cruising spares kit and can attest to the quality.

Link to comment
Share on other sites

12v is one matter 230v another

if you are rewiring your 12v then follow the good advice given by others on this thread.

if you are looking at 230v then as you said in your initial question domestic cabling and equipment is suitable (Caveat)

(AS long as) you remember it is a water environment so conduit or trunking is advisable where possible and cable routing should be as far away as possible from where water may affect the installation. A "proper" consumer unit should be fitted with breakers for earth leakage and live/neutral difference i.e. mcb and ecb breakers. this will protect any problems on the 230v system in the event of bad wiring or water influx etc..

as a recommended precaution i would also advise that fitted sockets/outlets be fuse protected as well .

With electricity (230v) always remember you can't see it smell it, hear it or feel it until it kills you! if you are not comfortable DON'T DO IT! get somebody qualified.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Sponsors

    Norfolk Broads Network is run by volunteers - You can help us run it by making a donation

×
×
  • Create New...

Important Information

For details of our Guidelines, please take a look at the Terms of Use here.