Adding an additional 13 amp plug socket

[discipleofsketch]

in the van I have a single 13 amp plug socket, linked to the hook-up socket and the original wiring for the fridge etc. done by Devon when it was converted back in the day.

I want to put an additional plug socket on the wardrobe, so is it safe to "daisy chain" another socket by wiring an additional 3 core cable into the back of the first socket, or should I intercept the wiring before it reaches the first socket and add on some kind of junction box (and if so what type?).

I know this is a basic question, but i've not done much mains stuff before...

[ghost123uk]

Yes it is safe as long as you carefully observe your live / neutral / earth and use decent mains cable. Take care of any places where the new cable might chafe on metal parts.

No need for a junction box, though you could if it meant it was easier. You can get the standard round white junction boxes from any electrical place and the likes of B&Q for about £2.50.

[discipleofsketch]

Yes it is safe as long as you carefully observe your live / neutral / earth and use decent mains cable. Take care of any places where the new cable might chafe on metal parts.

No need for a junction box, though you could if it meant it was easier. You can get the standard round white junction boxes from any electrical place and the likes of B&Q for about £2.50.

cheers!

[California Dreamin]

Also...rigid household '3 core' 2.5 twin & earth is not considered suitable. You will need to use a suitably rated multi-strand (flexible) round cable instead (the sort of wire you might use on a heavy duty 13amp extension lead etc) I think Wilko's still sell it by the metre off the reel.

Martin

[ghost123uk]

Good point ^^^

[Jeff J]

Also...rigid household '3 core' 2.5 twin & earth is not considered suitable.

Martin

Why?

[ghost123uk]

Because if it is subject to constant movement or vibration, the type of copper core it uses is prone to fracturing. It's no where near as flexible as "mains flex" as we used to call it. As Martin says, the best stuff for a job like this is the same as is used on mains extension leads.

[CovKid]

That applies to any cables used in a camper or mobile home, whether 12v or 240v, whether clipped up or not.

[discipleofsketch]

This is all good info, cheers - I was planning on using some rigid cable that I have lying around, but flex it is then.

[Jeff J]

Because if it is subject to constant movement or vibration, the type of copper core it uses is prone to fracturing. It's no where near as flexible as "mains flex" as we used to call it. As Martin says, the best stuff for a job like this is the same as is used on mains extension leads.

I would agree with you that flexible cable is probably the best choice but only for ease of installation reasons. As the cable is likely to be running very short distances, if it is properly fixed ( clipped etc.) there is not going to be enough movement in it to cause stress fracturing of the cores, so I can't see why twin & earth should not be " considered suitable ".

[California Dreamin]

Jeff, agreed, chances are 2.5 twin & earth wouldn't ever fracture but it is commonly accepted practice only to use multi-stranded flexible 3 core wire inside a camper or cara-van installation. It is quite surprising just how much panels and cupboards flex when driving and for the sake of £3 - £4 worth of cable is it worth the risk, however remote?
If you would like to trawl through British Standard 7671,
2001 (I E E Wiring Regulations, sixteenth edition) incorporating amendments No 1 & 2, Part 6,
Section 608, Divisions One and Two, Part 7, Chapters 72-74 and IEC Standard 364. It clearly states the use of 2.5mm 'multi-core' flexible cable to socket outlets and RCD although there are some proviso's over running cables through conduit and rigid plastic trunking etc.

Martin

[Oldiebut goodie]

Look how starter cable that is made from those very thick strands fracture at either end connection point. Seen it loads of times. No way would I countenance using single core cable in a vehicle or boat.It only takes the continuous vibration from an engine to begin to fatigue a single strand at any junction. You cannot prevent it very easily so why would you want to use/risk it? How often have you had a dead light bulb where the filament has just fatigued due to vibration - I have seen far more fail due to that rather than having just blown. QED.

[Jeff J]

How often have you had a dead light bulb where the filament has just fatigued due to vibration - I have seen far more fail due to that rather than having just blown. QED.

I think it more likely due to constant heating & cooling than vibration

[CovKid]

All getting a bit hypothetical now. Best practice is stranded throughout - end of. That said people fit what they want - fixed plenty where that appeared to be the approach of the owner. Stiff cable may be trouble-free - might not. Up to the owner. If I wired it, it would be stranded. Wouldn't want it coming back - thats the difference I suppose.

Lots of things work that aren't standard practice including twisting wires together and insulating with sellotape etc. Just not very professional. I guess if it was mine (not someone elses) and I had nothing else, two core & earth would have to do but if I also had flexible stuff I'd opt for that every time. Its also far easier to clip up frankly.

I've even seen telephone cable used to wire up LPG installations.

[Oldiebut goodie]

How often have you had a dead light bulb where the filament has just fatigued due to vibration - I have seen far more fail due to that rather than having just blown. QED.

I think it more likely due to constant heating & cooling than vibration

We have stronger filaments for boats to counteract the vibration not heating and cooling. Fact not thought.