Hook up leads

Hook up leads are a pain  They are heavy and winding them up is no fun, even with a patent winding reel. More and more sites have EHU plinths situated at the back of each pitch or between pitches and so you must unreel your whole 10 metres or more in a pretty zig zag behind the Dandy, leaving it coiled is not an option the temperature will rise alarmingly fast with a few amps going through the coil

  Today I made a 4 metre lead, cost of two connectors and cable less than £10  

Why can't you easily buy one  Not everyone has the knowledge and capability to make their own, and and unless competent to do so should not try.

(No I'm not going into the EHU lead business  )

The Wiring Regs say the lead should be 25 metres long plus or minus 2 meters. So between 23 & 27metres. This probably explains why they are all that length in the shops.

I suspect this is to ensure it is long enough without the user having to extend it. However I don't see any problems caused by having a shorter lead provided you also have a lead long enough for sites where it is needed. Longer than 25metres may cause a problem.

The problem with joining leads is two fold:

1 The join must be using a proper waterproof plug & socket. I don't think the standard blue plugs and sockets are sufficiently waterproof to lie on the ground in pouring rain or in puddles. A plastic bag round them also won't be good enough.

2 If there is a cross in the wiring in two extension leads used together it can result in a very dangerous situation. If neutral and earth are crossed in one and live and neutral in the other, the pair together have a live earth cross. All exposed metal will be live as soon as you plug it in. If the leads are used individually, the user would not be aware of any problem at all. This has resulted in deaths.

I'm not saying do not use a short lead. Just be aware of the problems of using two together.

navver



1) Are the 17th edition regs that prescriptive? I thought the 17th became less prescriptive and more suggestive. (For what little I know) Sorry I accept I might be pedantic on that and to be pedantic again is that within the bit that corresponds to specialist installations. [You must be registered and logged in to see this link.]
I was about to say that a Dandy is not a caravan and there are no regulations for other camping arrangements. I'm acutely aware of this after contacting the C&CC about an advert that implied an RCD fitted device was as per C&CC guidance and current regulations. Alas the ad didn't specifically mention the C&CC and there are no regulations specifically applying to other camping electric fitments.

Found this in the tlc piece:

Where a caravan appliance may be exposed to the effects of moisture, it must be protected to lp55 (protected from dust and from water jets). Every caravan which includes an electrical installation must be provided with a flexible lead not more than 25 m long fitted with a BS EN 60309-2 plug and a BS EN 60309-2 connector with the keyway at position 6h. The cross-sectional area of the cable must be related to the rated current of the plug as shown by {Table 7.6}.

Table 7.6 - Cross-sectional areas of flexible cables
---------------- and cords for supplying caravan connectors
Rated current of plug (A) Cross-sectional area (mm²)
16 2.5
25 4.0
32 6.0
63 16.0

So the 17th edition prescribes a 25m length not a maximum of 25m?

Joining Leads

navver wrote:The problem with joining leads is two fold:

1 The join must be using a proper waterproof plug & socket. I don't think the standard blue plugs and sockets are sufficiently waterproof to lie on the ground in pouring rain or in puddles. A plastic bag round them also won't be good enough.

2 If there is a cross in the wiring in two extension leads used together it can result in a very dangerous situation. If neutral and earth are crossed in one and live and neutral in the other, the pair together have a live earth cross. All exposed metal will be live as soon as you plug it in. If the leads are used individually, the user would not be aware of any problem at all. This has resulted in deaths.

I'm not saying do not use a short lead. Just be aware of the problems of using two together.

I have seen devices like this for commando leads but can't find one at the moment I think they may be IP56. I realise this 13amp one is only IP44

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Faults on two hook up leads. First of all the statistical approach. If there was a 1 in 50 chance of a wrongly wired hook up then the chances of having two is 1 in 2,500. So am I better of having two leads? No because the chance of one of the two being faulty is now 1 in 25.
Sorry now the serious point. If a lead is wrongly wired it is wrongly wired there might be evidence of a certain type of error being more prevalent but surely I could have just executed a live to earth cross?
Just thinking about this further. There is no protection from this as the RCD doesn't cut off the "earth" supply? Have I got this right.

Have the NICEIC done any research about a greater chance of neutral and earth cross wires since armoured cable became brown, black and grey?
Test not for navver, Jake, John or Perridot oh or Vicky if you are reading this how would you guess (don't look up) brown, black and grey is wired if used on single phase?
Or is this another good reason why we need to be wired or inspected by a professional electrician?  

navver Not trying to give you a hard time just being picky. It's nice to have people who know enough that I can ask picky questions.

Public apology to navver. navver PMed me some items on electrics. Unfortunately I was tied to other things and just realised I've not gone back and looked at them. If they are still readable can you resend please. Sorry

[

Have the NICEIC done any research about a greater chance of neutral and earth cross wires since armoured cable became brown, black and grey?
Test not for navver, Jake, John or Perridot oh or Vicky if you are reading this how would you guess (don't look up) brown, black and grey is wired if used on single phase?
Or is this another good reason why we need to be wired or inspected by a professional electrician?  ]


I haven't a clue and have been taught never to guess therefore I would look it up  

NEVER ASSUME........CHECK


PS I've got an orange torpedo but I can't remember its IP rating and its under the discovery seat at the moment. (and I've never needed to use it, leads are always too long  )

Many questions. Yes the IEE are absolutely prescriptive on the length of the lead. The lead shall be supplied with the caravan and shall be as described blah, blah. Too long and there are voltage drop and impedance problems. Too short and someone may try joining two together. I fully sympathise with Jake's point about trying to neatly lose 20metres of excess cable without tripping anyone up though.

As I said I don't think there is a problem as long as folks are fully aware that any join must be waterproof and correctly made and the cables must be correctly connected.

Faults on leads.
Live neutral cross, no-one would know without physically testing or inspecting. RCD will not trip.

Neutral earth cross, an RCD would trip if lead used on it's own as it would appear as a live earth fault, but if used at home with no RCD you would not know.

Both leads together gives a live earth cross. The RCD in the site EHU point may or may not trip. Current would flow from the RCD via live, cross to earth so into dandy chassis via bond. I don't think there is a return path for it to get back to the supply neutral, but not sure on this point.

New colours are a shambles. Europe didn't bother, we had a perfect system with red yellow & blue for the 3 phases, black for neutral and green for earth. Europe agreed to colours but insisted on brown, black & grey for the 3 phases, blue for neutral and green/yellow earth.  For single phase we just use brown for live, some may use the other colours in large 3 phase installations but we don't.

Yes, the fact blue can be neutral or live is a worry. Yes the new phase colours, brown black & grey are difficult to see in poor light on building sites. New and old colours are mixed in buildings when we build an extension. We have to use notices to that effect.

When doing circuit charts we used to use circuit DB1/1R. Now we have to meter lighting & power we split the boards to DB1L & DB1P then have way 1/ L1 instead of 1/R. Brown & Black have the same initial so L1, L2 & L3 are used instead.

So a simple DB1/1R becomes DB1L/1/L1. But it might be DB3L/1/L2 or was that DB2L/3/L3. My head hurts.

I think the risks of cross connections are much greater in the blue plugs and sockets. No fuse, just 3 pins. Probably fairly easy in a 13Amp plug.

If using 3 core cable coloured brown, grey & black you should fit coloured sleeves at each end to indicate their true colours. Not sure what colour the orange cable is. Some 3 core is brown, grey & black when intended for a 3 phase supply only without a neutral.

Jake

I haven't a clue and have been taught never to guess therefore I would look it up study

Yes well how do I argue against someone who is right only to say that the UK had a set of wiring colours. We changed them for flex notionally because of the possibility of colourblindness. We then many years later changed our cable or twin and earth colours to the same scheme ish. Earth still had to be sleeved at the ends. Then we accept a pan European colour scheme where the colours are hard to differentiate and one of them was previously used for another purpose. Then just who approved what we do is a bit circumspect as well. There is nothing like sensibly derived pan European regulations and this looks nothing like......  

navver

D'oh I was only considering the RCD on the Dandy forgetting that the hook up points RCD will then trip.
I've just spent half an hour considering your second hook up even with a third set of hook up cables can we have a point were both RCD's don't trip only to realise that there is no imbalance when Live and Neutral are transposed but in all other cases at least one of the RCDs would trip.  Please correct me if I'm wrong. I can though see it's relevance if you only have the site (or 1 home RCD) YES YES YES just got this. Though I think you have to have the cables in the opposite order you just said. Live Neutral mix up then N (live) to E (live) L (neutral) to L (neutral) E (earth) to N(earth) hence  no I'm still wrong the only fault I can see is Live to Erth with just the Dandy RCD (No site RCD) will have a live earthing on the Dandy and you can trip to an actual Earth.
If I'm wrong navver you will have to spoon feed me and if you are spoon feeding me I'd expect you need to help others.

Oh I'm tired after that the circuit designation questions will have to wait.

P.S. Saw the big copper earths in Wales near the hook ups last week. A bit worrying that the ground round them was so cracked and dried.