Crimping t/y splice into 16mm2 cable

[BMC problems]

And yes, planning to fuse everything.

If anyone has a measurement for the inside diameter of a 25mm crimp thay would be super useful!

If anyone has a measurement for the inside diameter of a 25mm crimp thay would be super useful!

 

I could google that for you if you want;

 

http://ie.rs-online.com/web/p/crimp-butt-splice-terminals/0119211/

[towpathrider]

 

I could google that for you if you want;

 

http://ie.rs-online.com/web/p/crimp-butt-splice-terminals/0119211/

Ok great, thabks. I guess that was obvious but for some reason didnt think the specs would be out there.

Edited April 12, 2016 by towpathrider

[RLWP]

The cable is actually a 50m drum of earth wire that i got a good price on.

 

How many strands has it got?

 

Richard

[Guest]

 

Clumsy? How so? in a box they look like a fairly neat solution - do you use rings once the tap is bolted tight?

The main argument would seem to be one of cost, at £10 the pair for 16mm

 

I think rings to a bus bar in an IP65 box at 4 or 5 locations is the way to go. Then have a fuse in each box, a clever solution would be an LED bridging each fuse so if it blew the LED would light although fault finding is not complicated - "the saloon lights are out, it's probably the saloon junction box fuse" not beyond the wit of man.

I mean that the "line taps" that we used to use would be clumsy. The principle however is similar. I have no experience of the ones illustrated.

My post is edited to avoid confusion.

Edited April 12, 2016 by Guest

[GUMPY]

 

 

Hmmmmm.......not so sure........a 50mm crimp slips easily over the insulation of a 25mm tri-rate. I don't have any 16mm tri-rate on board to check but I would have thought a 35mm would go over it

35 doesn't go over that's what I tried!

May work with thin insulation but.......

I could start an argument now by making the statement "voltage drop is not as important as it's made out to be"

For one Chris I might just agree with you.

Now most are using LED lighting there is very little volt drop as the current is so low.

[MtB]

I could start an argument now by making the statement "voltage drop is not as important as it's made out to be"

 

 

Oh no you couldn't!

[towpathrider]

 

How many strands has it got?

 

Richard

I think it has 6 strands, will have to check. But it would be hard to cut through one with a stanley knife.

 

I know i could probably have gotten away with using smaller cable, but using this method I would still have the same problem, unless the cable was small enough to solder, and in my experience getting larger cables hot enough to flow solder is impractical and melts insulation.

 

Maybe im just doing it wrong. . .

Edited April 12, 2016 by towpathrider

[GUMPY]

If it only has six strands its not suitable for use in a boat!

The 16mm I use has over 100 strands

Edited April 12, 2016 by Loddon

[John V]

Agree ....sounds like BS6004 conduit cable. not recommended for marine use

16mm2 tri rate has 126 strands has 1.55mm insulation and an external diameter of 9.05mm

[Tony Brooks]

 

I would take issue with that as a categorical statement.

 

Often the cable dimension on a 12v circuit are way in excess of the fused ratings as often it is determined by the permissible volt drop as opposed to the current carrying capacity. As long as the carrying capacity of the spurs is in excess of the main fuse this is not the case

 

I would not unless the OP is going to rewire ALL the cables fixed to equipment by the manufacturer in 16 sq mm CCSA. It will be almost impossible to fuse the 16 sq mm CCSA cable to allow for the thin wires fixed to things like certain light fittings, shaver sockets etc. so they do not blow when several loads are on together.

 

I am sure that you know as well as I do that on any circuit the fuse must be rated for the thinnest cable.

I

If it only has six strands its not suitable for use in a boat!

The 16mm I use has over 100 strands

 

and if its to have an RCD probably illegal - not that its likely to be checked.

[John V]

 

I would not unless the OP is going to rewire ALL the cables fixed to equipment by the manufacturer in 16 sq mm CCSA. It will be almost impossible to fuse the 16 sq mm CCSA cable to allow for the thin wires fixed to things like certain light fittings, shaver sockets etc. so they do not blow when several loads are on together.

 

I am sure that you know as well as I do that on any circuit the fuse must be rated for the thinnest cable.

I

 

and if its to have an RCD probably illegal - not that its likely to be checked.

 

I think you need to go and read the OP instead of jumping off.

 

1 ) it is a 12V circuit .......you don't use RCD's on 12v DC circuits

 

2 ) He says he will be installing sockets not lights

 

3 ) Your first part about fusing the 16mm2 cable is totally wrong. It has already been stated that it is purely because of the voltage drop.....for all you know he might be fusing the system at 10A in which case he could use 0.5mm2 spurs safgely

[Guest]

 

I think you need to go and read the OP instead of jumping off.

 

1 ) it is a 12V circuit .......you don't use RCD's on 12v DC circuits

 

2 ) He says he will be installing sockets not lights

 

3 ) Your first part about fusing the 16mm2 cable is totally wrong. It has already been stated that it is purely because of the voltage drop.....for all you know he might be fusing the system at 10A in which case he could use 0.5mm2 spurs safgely

I took RCD to mean Recreational Craft Directive.

[John V]

If that is so I stand corrected but when talking about electrics it pays to be precise

 

however the op talks about re-wiring so I would think it unlikely to be required

Edited April 12, 2016 by John V

[towpathrider]

Agree ....sounds like BS6004 conduit cable. not recommended for marine use

16mm2 tri rate has 126 strands has 1.55mm insulation and an external diameter of 9.05mm

Can anybody point me towards the documentation?

 

Is this a recommendation or a requirement for BSS

 

"marine" gets a lot more extreme than interior under gunwhale wiring on inland waterways.

 

The cable won't be going inside the engine room, 12v distribution is on engine room bulkhead in rear cabin.

 

Yes this is a rewire, its not a new boat.

Edited April 12, 2016 by towpathrider

[WotEver]

I took RCD to mean Recreational Craft Directive.

As did I. Even if it's not going to be RCD certified surely one should attempt to emulate RCD best practice?

Can anybody point me towards the documentation?

 

Is this a recommendation or a requirement for BSS

 

"marine" gets a lot more extreme than interior under gunwhale wiring on inland waterways.

 

The cable won't be going inside the engine room, 12v distribution is on engine room bulkhead in rear cabin.

 

Yes this is a rewire, its not a new boat.

It's a recommendation. Depending on the examiner he could fail it as unsafe (because it would be).

 

Tony

[Tony Brooks]

 

I think you need to go and read the OP instead of jumping off.

 

1 ) it is a 12V circuit .......you don't use RCD's on 12v DC circuits

 

2 ) He says he will be installing sockets not lights

 

3 ) Your first part about fusing the 16mm2 cable is totally wrong. It has already been stated that it is purely because of the voltage drop.....for all you know he might be fusing the system at 10A in which case he could use 0.5mm2 spurs safgely

 

Perhaps I am not the only one who needs to read what the OP originally wrote. he specifically refers to "and a couple of wired in static/stationary 12v devices".

 

Now, you may know exactly what those couple of devices are and how their wiring is attached but I do not.

 

I think suggesting that spurs with a reduced cable size need not be fused is not very responsible.

[John V]

N

 

It's a recommendation. Depending on the examiner he could fail it as unsafe (because it would be).

Tony

 

To say it is unsafe is not correct.

 

If it was unsafe it wouldn't be still listed in the BSC as acceptable if already installed.

even Solid core cable is acceptable in an existing installation so that terminology is not correct.

There are many wiring methods that are not described as "best practice" and are perfectly safe.

The only problem is that if there is ever an insurance claim involved, it might be necessary to prove the method safe in court, whereas if something is installed to "best practice" it is automatically deemed to have been a safe installation (even if badly executed)

 

If a system as that described by the op was in a boat owned by myself, providing the joints were well made and insulated and the fusing correct and correctly supported. I certainly wouldn't bother to change it (I might grumble about it's inflexible nature as a system but I would sleep quite happily at night sure that it was quite safe)

[John V]

 

I would take issue with that as a categorical statement.

 

Often the cable dimension on a 12v circuit are way in excess of the fused ratings as often it is determined by the permissible volt drop as opposed to the current carrying capacity. As long as the carrying capacity of the spurs is in excess of the main fuse this is not the case

 

Tony I refer you back to my post #7 when I first took issue with your statement about fusing every spur

[ditchcrawler]

 

 

Really? Can you (or anyone) cite the rule please?

 

Thanks.

I did say think, I will look

[GUMPY]

The OP is seems set on doing it "his way" with unsuitable cable and a dodgey connection methods.

Yet another rank amateur bodging boat electrics..........

[towpathrider]

The OP is seems set on doing it "his way" with unsuitable cable and a dodgey connection methods.

Yet another rank amateur bodging boat electrics..........

Hmm. . .

 

I think there are a lot of people on here who like to throw regulations at a problem (often without referencing them) perhaps to prove they know better etc. . .

 

First of all, the cable type is a recommendation. There was a lot of solid strand cable in the boat already, and it got through a BSS, no problem. Does that mean the BSS inspector/surveyor is a "rank amateur" ?

 

Maybe we coukd have a constructive conversation about why the recommendation is in place?

 

From what I have read, and please correct me, the problem with solid strand wire is mainly due to stress fracturing, and I certainly would not use solid strand 1.5mm twin mains wire for 230v, due to this, even though plenty was fitted in my boat when it passed BSS, and i have subsequently replaced it.

 

I cant imagine 16mm fracturing under stress though.

 

But are there any other reasons is this recommendation is in place?

 

http://www.clevelandcable.com/products/658tq-marine-cable-offshore-cable-bs6883-ukooa-6mm300mm-p/

 

How many of you can honestly say your 30 year old boats are fully wired with bs6883 cable?

 

I'm not trying to say that just because other people flout regulations means that its ok, but lets have a constructive argument about why its a recommendation.

 

If people know why they shouldn't break rules, then they will more likely follow them.

 

As to the connection methods, whats so dodgy about them?

 

 

I will be running several sockets, and a couple of 12v applicances directly from this 16mm2 circuit, each socket is fused, and each appliance will be fused as well. I plan to use 6mm or 4mm cable for the spurs.

 

Max current draw from any one socket will be 10a (occasional use of powerful laptop)

 

The appliances will be a small tv/monitor, 12v stereo, and maybe a couple of 5v usb devices via a buck converter.

 

 

I'm not set on doing it "my way", otherwise I wouldn't have bothered with the post,

If you were to wire 16mm2 12v to "best practice" standards how would you do it?

Edited April 12, 2016 by towpathrider

[WotEver]

Q: Why is it a recommendation?

 

A: Because solid (or even 6 strand) cable isn't flexible and therefore will eventually suffer from vibration-induced fracture. That might take decades or it might take a month but it will (not might) happen.

 

Tony

 

The tinned copper wire you linked to above is great for the salty types (and superior to un-tinned in any situation) but that's not what folk are saying here. They're simply saying that boats should be wired with flexible cable just like cars are.

[towpathrider]

Q: Why is it a recommendation?

 

A: Because solid (or even 6 strand) cable isn't flexible and therefore will eventually suffer from vibration-induced fracture. That might take decades or it might take a month but it will (not might) happen.

 

Tony

 

The tinned copper wire you linked to above is great for the salty types (and superior to un-tinned in any situation) but that's not what folk are saying here. They're simply saying that boats should be wired with flexible cable just like cars are.

Ok, thanks. I checked and the wire is 7 strand, BS EN 50525-2-31 which I believe replaces BS6004.

[ditchcrawler]

Ok, thanks. I checked and the wire is 7 strand, BS EN 50525-2-31 which I believe replaces BS6004.

It would be 7, they lay 6 round the centre one .

[GUMPY]

I said earlier how I would do it if I had to do it with 16mm. The 4x 12v oulets that I inherited on this boat are wired in 6mm, daisy chained using 30amp terminal block one run down each side of the boat, voltage drop has not been a problem.

Personally I don't use 12v for high current items prefering to use 230v for that. I run my USB chargers, dongles etc from 12v but that's about it. My last boat had no 12v sockets at all.

As for choice of cable I use tri-rated which is overspeced for the job but is of a consistent standard unlike many "auto" cables.

Edited April 12, 2016 by Loddon