I've looked through the Wiki on taking power outside and read the bits about
single external socket on an existing ring and RCD protection.

I can't immediately find anything about installing the single external
socket.

What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an external
wall near to an internal 13A socket so I can take a spur through the wall.

This to replace the current arangement where the cable goes through a partly
open window and has a [round pin - 13A] adapter to plug into an internal
socket.

The sockets themselves look reasonably priced, e.g.
http://www.screwfix.com/prods/40962/...ocket-16A-240V
assuming this is the sort of thing I should be using.

As far as I can tell I have only MCBs (MEM M6) in the fuse board and a
single whole house RCD so presumably I will have to add an RCD to stop the
whole house tripping should there be a problem.

Plan is therefore roughly to install a switched spur internally
incorporating an RCD, take a cable through the wall and into the back of an
external socket.
Interesting part may be sealing the back of the external socket to the wall
as the wall is a sharp shell pebbledash.

Oh, and if I do this in the (very long) kitchen/diner in the diner part is
this something that falls foul of Part P?

Cheers

Dave R
--
No plan survives contact with the enemy.

Helmuth von Moltke the Elder

David WE Roberts wrote:
I've looked through the Wiki on taking power outside and read the bits
about single external socket on an existing ring and RCD protection.

I can't immediately find anything about installing the single external
socket.

What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an
external wall near to an internal 13A socket so I can take a spur
through the wall.


not sure that's appropriate - aren't the blue sockets more amps than
13A? all I did was get waterproof 13A sockets for outside, and spur em
off the inside by drilling through the wall.

This to replace the current arangement where the cable goes through a
partly open window and has a [round pin - 13A] adapter to plug into an
internal socket.

The sockets themselves look reasonably priced, e.g.
http://www.screwfix.com/prods/40962/...ocket-16A-240V

assuming this is the sort of thing I should be using.

As far as I can tell I have only MCBs (MEM M6) in the fuse board and a
single whole house RCD so presumably I will have to add an RCD to stop
the whole house tripping should there be a problem.


RCBO is better. replaces the MCB.



Plan is therefore roughly to install a switched spur internally
incorporating an RCD, take a cable through the wall and into the back of
an external socket.
Interesting part may be sealing the back of the external socket to the
wall as the wall is a sharp shell pebbledash.

lots of favorite goo. Hot glue, mastic, silicone, car body filler...



Oh, and if I do this in the (very long) kitchen/diner in the diner part
is this something that falls foul of Part P?


I pee on part P.

Who honestly cares?.




Cheers

Dave R

On 08/06/2010 14:22, The Natural Philosopher wrote:
What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an
external wall near to an internal 13A socket so I can take a spur
through the wall.

not sure that's appropriate - aren't the blue sockets more amps than
13A? all I did was get waterproof 13A sockets for outside, and spur em
off the inside by drilling through the wall.

The blue sockets are rated to 16A.

Not that that particularly matters. We have been running a caravan from
a 13A three pin plug for 14 months without blowing any fuses.

"David WE Roberts" wrote in message
...
I've looked through the Wiki on taking power outside and read the bits
about single external socket on an existing ring and RCD protection.

I can't immediately find anything about installing the single external
socket.

What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an
external wall near to an internal 13A socket so I can take a spur through
the wall.

Problem here is, the normal caravan sockets are only rated to 16A, and your
ring main will be potected to 32A - you either need to install a new circuit
back to the consumer unit, and protect it at 16A, or supply it from the
ring, via a FUSED spur, fused at 13A (I guess you won't be drawing more than
that in the van?)

This to replace the current arangement where the cable goes through a
partly open window and has a [round pin - 13A] adapter to plug into an
internal socket.

Sounds sensible.

The sockets themselves look reasonably priced, e.g.
http://www.screwfix.com/prods/40962/...ocket-16A-240V
assuming this is the sort of thing I should be using.

As far as I can tell I have only MCBs (MEM M6) in the fuse board and a
single whole house RCD so presumably I will have to add an RCD to stop the
whole house tripping should there be a problem.

If you do that, then you will have two RCD's the main one being more loaded
would probabaly still trip first. Unless your cusumer unit is a split type
already, which you say it isn't, you will need to either replace the
existing one, or add another consumer unit with either another RCD, or
preferablly a main switch and an RCBO, plus some spare ways for future use.

Plan is therefore roughly to install a switched spur internally
incorporating an RCD, take a cable through the wall and into the back of
an external socket.

As I siad before, if the ring is already on an RCD, this second one is
pointless.

Interesting part may be sealing the back of the external socket to the
wall as the wall is a sharp shell pebbledash.

I would make sure the hole from the inside to the outside slopes downwards
slightly, so water cant flow into the house, put the cable through and then
squirt silicone seaent in the hole, once this is set, mount the backplate
for the blue socket, and then seal this on the inside with more silicone,
then wire it up once this has set.

The other option, is to install a single waterproof standard socket directly
to the ring, then keep the adaptor, but it would then be plugged in
outside. - One that still seals when in use, like the MK ones here
http://www.tlc-direct.co.uk/Main_Ind...ets/index.html


Oh, and if I do this in the (very long) kitchen/diner in the diner part is
this something that falls foul of Part P?

Probabaly

Cheers

Dave R
--
No plan survives contact with the enemy.

Helmuth von Moltke the Elder

David WE Roberts wrote:
I've looked through the Wiki on taking power outside and read the bits
about single external socket on an existing ring and RCD protection.

What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an
external wall near to an internal 13A socket so I can take a spur
through the wall.


OK.

The sockets themselves look reasonably priced, e.g.
http://www.screwfix.com/prods/40962/...ocket-16A-240V

assuming this is the sort of thing I should be using.

Yes.

As far as I can tell I have only MCBs (MEM M6) in the fuse board and a
single whole house RCD so presumably I will have to add an RCD to stop
the whole house tripping should there be a problem.

You could add a local RCD, except that there will be no guarantee that
the local RCD will trip in preference to the whole-house RCD.

If you supply the spur from a ring main, then the ring main is going to
need an rcd anyway, so you are always going to have a discrimination
problem if you use a local RCD unless you pull in a radial circuit just
for the outdoor socket from a non-rcd-protected MCB in the consumer
unit. Except that you don't have any non-RCD protected ways in the
consumer unit. ;-(

So, either you would need to change the consumer unit for a split-load
jobbie, or add Henley blocks and a second consumer unit, or you would
need to change the whole-house RCD for a main switch and then change
some of your MCBs for RCBOs.

If you did any of these, you could (if you wanted) ditch the RCD spur
and have an RCD in the consumer unit.


Plan is therefore roughly to install a switched spur internally
incorporating an RCD, take a cable through the wall and into the back of
an external socket.

OK, but you would need to ensure that the RCD spur is fused at 13A.

Interesting part may be sealing the back of the external socket to the
wall as the wall is a sharp shell pebbledash.

Use flexible cord 1.5mm2 to connect the spur to the socket outlet. Drill
as small a hole as possible in the back of the socket. fit the cable to
the socket. Seal up the hole with flexible silicone and then fit the
whole assembly to the wall. Finally, terminate the flex to the spur.


Oh, and if I do this in the (very long) kitchen/diner in the diner part
is this something that falls foul of Part P?

;-)

Dave Osborne wrote:
David WE Roberts wrote:
I've looked through the Wiki on taking power outside and read the bits
about single external socket on an existing ring and RCD protection.

What I want to do is to put a female blue round pin outlet with a
spring cover and pointing downwards (just like you get on campsites)
on an external wall near to an internal 13A socket so I can take a
spur through the wall.


OK.

The sockets themselves look reasonably priced, e.g.
http://www.screwfix.com/prods/40962/...ocket-16A-240V

assuming this is the sort of thing I should be using.

Yes.

As far as I can tell I have only MCBs (MEM M6) in the fuse board and a
single whole house RCD so presumably I will have to add an RCD to stop
the whole house tripping should there be a problem.

You could add a local RCD, except that there will be no guarantee that
the local RCD will trip in preference to the whole-house RCD.


go for 100mA main trip in the house, and 30mA RCBO's where needed.

On 8 June, 14:13, "David WE Roberts"
wrote:

What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an external
wall near to an internal 13A socket so I can take a spur through the wall.

Needs protection for that circuit alone (it _might_ not, but probably
will). This is most conveniently obtained through a packaged solution
in one IP-rated box that can screw directly to the outside wall. This
also puts the RCD test button and the overcurrent reset on the
outside, where you can get to them most easily.

In article ,
David WE Roberts wrote:
I've looked through the Wiki on taking power outside and read the bits
about single external socket on an existing ring and RCD protection.

I can't immediately find anything about installing the single external
socket.

What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an
external wall near to an internal 13A socket so I can take a spur
through the wall.

I take it you want to use a 16 amp BS socket like camp sites so you can
use an existing lead? I'd give some thought to using a 13 amp one as it
can have other uses. And weatherproof combined 13 amp outlet/RCDs are
readily available.

--
*Re-elect nobody

Dave Plowman London SW
To e-mail, change noise into sound.

"John Rumm" wrote in message
o.uk...
On 08/06/2010 14:13, David WE Roberts wrote:

I've looked through the Wiki on taking power outside and read the bits
about single external socket on an existing ring and RCD protection.

I can't immediately find anything about installing the single external
socket.

Installing the sockets itself is usually straight forward if you can drill
straight through from the back of it.

What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an
external wall near to an internal 13A socket so I can take a spur
through the wall.

Yup, that's ok.

John,

Is it OK to feed a 16A socket from a 32A ring?

I assumed not, seen as there isn't a fuse in the blue plug or socket!

Toby...

Toby wrote:

"John Rumm" wrote in message
o.uk...
On 08/06/2010 14:13, David WE Roberts wrote:

I've looked through the Wiki on taking power outside and read the bits
about single external socket on an existing ring and RCD protection.

I can't immediately find anything about installing the single external
socket.

Installing the sockets itself is usually straight forward if you can
drill straight through from the back of it.

What I want to do is to put a female blue round pin outlet with a spring
cover and pointing downwards (just like you get on campsites) on an
external wall near to an internal 13A socket so I can take a spur
through the wall.

Yup, that's ok.

John,

Is it OK to feed a 16A socket from a 32A ring?

I assumed not, seen as there isn't a fuse in the blue plug or socket!

Toby...

The IEE Wiring regulations don't cover this situation for domestic ring
final circuits.

The basic principle is that you fuse (at the consumer unit) to protect
the installed cables, as fire caused by overheating in installed cables
(not electric shock or anything else) is about 90% of the risk in a
fixed electrical installation.

At the point where you connect the socket outlet to the installed cable,
you have to consider the continuous current carrying capacity of the
plug/socket outlet and the breaking capacity of the plug/socket combination.

In the case here, the continuous current carrying capacity is 16A and
the breaking capacity is 125% of nominal or 20A.

In a domestic environment I would consider any of the following: -

1. A 16A radial circuit supplying one or more 16A socket outlets.
2. A 20A radial circuit supplying two or more 16A socket outlets.
3. A 32A ring final circuit supplying a 13A fused spur for each 16A
socket outlet.
4. A 32A ring final circuit socket supplying one or more outlet combi
boxes[1] with local provision for 16A MCBs.

[1] e.g. http://www.lewden.net/lewden/catalog...ook/combin.htm

"Dave Osborne" wrote in message
...
Toby wrote:

"John Rumm" wrote in message
o.uk...
On 08/06/2010 14:13, David WE Roberts wrote:

I've looked through the Wiki on taking power outside and read the bits
about single external socket on an existing ring and RCD protection.

I can't immediately find anything about installing the single external
socket.

Installing the sockets itself is usually straight forward if you can
drill straight through from the back of it.

What I want to do is to put a female blue round pin outlet with a
spring
cover and pointing downwards (just like you get on campsites) on an
external wall near to an internal 13A socket so I can take a spur
through the wall.

Yup, that's ok.

John,

Is it OK to feed a 16A socket from a 32A ring?

I assumed not, seen as there isn't a fuse in the blue plug or socket!

Toby...

The IEE Wiring regulations don't cover this situation for domestic ring
final circuits.

The basic principle is that you fuse (at the consumer unit) to protect the
installed cables, as fire caused by overheating in installed cables (not
electric shock or anything else) is about 90% of the risk in a fixed
electrical installation.

At the point where you connect the socket outlet to the installed cable,
you have to consider the continuous current carrying capacity of the
plug/socket outlet and the breaking capacity of the plug/socket
combination.

In the case here, the continuous current carrying capacity is 16A and the
breaking capacity is 125% of nominal or 20A.

In a domestic environment I would consider any of the following: -

1. A 16A radial circuit supplying one or more 16A socket outlets.
2. A 20A radial circuit supplying two or more 16A socket outlets.
3. A 32A ring final circuit supplying a 13A fused spur for each 16A socket
outlet.
4. A 32A ring final circuit socket supplying one or more outlet combi
boxes[1] with local provision for 16A MCBs.

[1] e.g. http://www.lewden.net/lewden/catalog...ook/combin.htm


Thanks for all the input.
I assume this is similar:
http://www.screwfix.com/prods/71686/...-2P-E-RCD-IP44
It is also over £100 and so is slightly OTT for my simple domestic needs.
The 13A fused spur sounds the best option as it replicates the current more
informal arrangement with the 13A plug and adapter.
Double pole fused switch to allow it to be turned off from indoors is also
good - this would be essential if the socket was on the front wall to
prevent someone 'borrowing' electricity when we were away.
I am still slightly puzzled by some of the Screwix listings as they
sometimes seem to list what looks like the same thing from the same
manufacturer at slightly different prices.

Is there scope for a specific Wiki entry for all those caravan and camper
owners who keep their outfits at home?

Cheers

Dave R
--
No plan survives contact with the enemy.

Helmuth von Moltke the Elder

On 09/06/10 09:12, David WE Roberts wrote:



Thanks for all the input.
I assume this is similar:
http://www.screwfix.com/prods/71686/...-2P-E-RCD-IP44

It is also over £100 and so is slightly OTT for my simple domestic needs.
The 13A fused spur sounds the best option as it replicates the current
more informal arrangement with the 13A plug and adapter.
Double pole fused switch to allow it to be turned off from indoors is
also good - this would be essential if the socket was on the front wall
to prevent someone 'borrowing' electricity when we were away.
I am still slightly puzzled by some of the Screwix listings as they
sometimes seem to list what looks like the same thing from the same
manufacturer at slightly different prices.

Is there scope for a specific Wiki entry for all those caravan and
camper owners who keep their outfits at home?

Cheers

Dave R

The IEE 17th regs do not approve of unshuttered power sockets (or
specifically they only approve a few particular BS standard sockets that
happen to all be shuttered) in a domestic installation (I will find the
reg reference if you'd like proof).

However, I would say that use of the interlocked socket would meet the
spirit of the regulations (ie cannot have live holes) - ie I would be
totally happy to justify that to the face of a BCO, NIC inspector or
anyone else.

100 quid sounds expensive. Lets look:

http://www.reconelectrical.co.uk/ind...roductId=27069

http://cgi.ebay.co.uk/Gewiss-GW66206...35a635ffd2f75c

(Gewiss is a good make BTW)

http://www.gwsupplies.co.uk/p/5467/i...p44+iec309.htm

If you don't use one of these, I would suggest at the very least
mounting it high, out of reach of kids.

Obviously, you *must* have it RCD protected (30mA/40mS - standard RCD)
as it is feeding outside.

As others have said, you get no guarantees with cascaded RCDs unless the
head end is a time delayed type used on TT supplies.

However, with a double pole isolator it would not be dangerous to rely
on the house RCD - just inconvenient if it trips, which IME is rare
enough to live with if the alternative is impractical. At least make
sure you can isolate it on both poles, preferably from within the house
(eg at the fused spur) because if it does get full of water you will
have a means to restore the rest of the house power.

On the subject of a 13A fused spur - perfectly OK and approved to do
this (this is even mentioned in the IEE Wiring Matters magazine for a
whole shed supply as a possibility. You are underfusing rather than
overfusing a 16A socket, so the worst that happens is the fuse goes. Not
dangerous. Incidently, you'll pull 16A through a 13A fuse for quite a
long time before it blows. But for your setup I doubt you will get
anywhere near that.

BTW - I've been through the theory because I fancy a couple of these
under the soffits on their own 20A combined RCBO feed.

HTH

Tim

--
Tim Watts

Hung parliament? Rather have a hanged parliament.

Tim Watts wrote:

BTW - I've been through the theory because I fancy a couple of these
under the soffits on their own 20A combined RCBO feed.

That must be some Xmas display you are planning ;-)

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

On 09/06/2010 12:17, Chris J Dixon wrote:
Tim Watts wrote:

BTW - I've been through the theory because I fancy a couple of these
under the soffits on their own 20A combined RCBO feed.

That must be some Xmas display you are planning ;-)

Chris

Hmm. Animated neon of Rudolph and Santa...

"Daady - Santa keps trying to jump up onto Rudolph and he can't manage
so he's trying again"

"Err I don't think that's what he's doing son..."

Or a massive laser display onto the clouds

Couple of comments,

#1 exporting PME (TN-C-S) to a caravan may upset the DNO, however
since it is a camper van I do not think it is perhaps practical to do
a local earth rod since by its nature the van is somewhat mobile
(unless it is essentially stationary?).

#2 You can get interlocked sockets cheaply online such as the compact
IP55 Geweiss unit at www.discountelectrical.com & from Ebay too.

#'3 Do you really need a BS4343 outlet, most likely interlocked, on
the side of the house? Why not use an MK Masterseal 13A socket (usable
with everything), and make up a simple lead with 13A plug on one end
going to BS4343 inline-socket on the other with a BS4343 appliance-
inlet on the caravan? You can use the outdoor socket for anything.

Cable can enter the rear of an MK socket via their special backbox -
it has no top/side knockouts and instead has a single rear hole that
takes MK's own 20mm conduit grommet. The conduit is used to sleeve the
cable through the wall. As for pebble dash, use long screws with small
plastic spacers (check Ebay, various diameters & depths) which will
standoff the socket from the wall yet mechanically retain it via all 4
fixings.

Interlocked BS4343 tend to be quite big ugly beasts, the Geweiss
compact unit is an exception but still about "a foot".