nordelettroica consumer unit

[GStockton]

To David L if you have a copy of bs7671 in front of you have a read of Definitions of Live conductor? you will find it is now called Line conductor and included within this is the neautral conductor,hence why both poles are required to be switched.
There are even quite a few questions on the Caravans and Mobile homes section of the City & Guilds 17th edition exam now.
And comming soon there wil be no main RCD fitted to caravans but will be going to a double pole main switch and 2 or 3 circuits of RCBO,s pos of 10 milli amp rated to eliminate nuisence tripping of the pillar RCD.
I have yet to test and inspect a site which complys with the 17th edition requirement for rcd protection for each 16a socket,but at least we know that BS 7671 is not retrospective

 

[paulthomas]

I am completely overpowered by all these technical responses!As an amateur everything I am totally impressed.......but my understanding has now dipped to below zero.
.and I thought caravans should be user friendly!

 

[Damian]

Paul, caravanning is easy, the equipment within it is not when it comes to rules and regulations, which is why it is so important to get up to date professional help with many of the items.
There may only be two or three "services" in a van, but two of them will kill without even thinking about it, given the chance, the other will make you very wet !!!

As G Stockton has pointed out, both conductors in a cable are considered to be potentially "Live", which is why both must be fully isolated when a switch is set to OFF, simply to protect the end user.

 

[paulthomas]

Fairenoughski!
MERRY CHRISTMAS
PS I appear to have a problem with the Christmas tree's lights.

 

[Damian]

LOL,,,,,,,,,dosent everyone at this time of year.

Tesco,half price replacements if your quick!!

Have an "illuminating" and happy Christmas

 

[GStockton]

Lets go back to my first caravan, a Thompson Glen, my name is Glenn thats why I bought it.

No electrics, no fridge, a 2 ring gas burner, and 2 gas lights with mantels Simples

Did it give us fun? you bet

happy christmas to all

 

[xtrailman]

Lets go back to my first caravan, a Thompson Glen, my name is Glenn thats why I bought it.

No electrics, no fridge, a 2 ring gas burner, and 2 gas lights with mantels Simples

Did it give us fun? you bet

happy christmas to all

Our first caravan was a Monza 1200s, we loved it, no electric, no lights, except two gas points on the wall with parts missing.
And the best part, the foot pump for the water. Later upgraded to an electric pump, operated by a push button fitted on the side of the sink. Which i was very proud of !.

When we towed in rain i had to limit speed to 40mph, or the front seams would open up and water weeped into the caravan!
And then if we wanted to reverse the caravan i had to get out of the car and move the reverse lever over!

 

[Clive-Cardiff]

With all this talk of double pole switches being mandatory in caravans, does this mean I can throw the polarity checker out the window.
I always check polarity when setting up in UK and abroad, am I wasting my time?

 

[Damian]

Clive, as far as AC is concerned, it makes no difference which conductor is connected to which terminal as the polarity changes every half cycle anyway, which is why it is called Alternating Current.
The only reason to use a standard (for domestic use) wiring systemm with brown being determined Line (or Live as most call it) is to ensure the single pole switches acually disengage the Line feed. The actaul appliances connected to it dont care which is which.

The same is not the case for DC where polarity is very important

 

[xtrailman]

Clive, as far as AC is concerned, it makes no difference which conductor is connected to which terminal as the polarity changes every half cycle anyway, which is why it is called Alternating Current.
The only reason to use a standard (for domestic use) wiring systemm with brown being determined Line (or Live as most call it) is to ensure the single pole switches acually disengage the Line feed. The actaul appliances connected to it dont care which is which.

The same is not the case for DC where polarity is very important

Not quite true Damian.

The line or live conductor isn't connected to earth.

While the neutral is, usually only a few volts exist between earth and neutral, while full volts are between live and earth.

Which is why the live is fused.

 

[JohnGriffiths]

Damian, don't know whether that answers Clives question and I would like to know as well. Are all current touring caravans DP sockets? When did the change occur? My year 2000 Bailey was certainly not as I used to check for reversed polarity by prodding a meter into the neutral with the switch off. My current Swift 2010 has a warning light on the consumer unit, but in fact I've had an occasion in France where it has lit up both with a straight cable and a L-N swapped cable.

 

[Damian]

Ray I was trying to keep it simple, I do not think many people actually know that there is no "earth" as such and that it is connected straight to the neutral, which acts as an "earth, or reference.

John, I do not know when changes were made, but every switched socket "should" be DP, however I would not be surprised to find SP fitted in some vans , but I have not come across any yet.

 

[Guest]

After the transformer on the post feeding our site blew up, I was talking to one of the guys fixing it, they refer to live and neutral as line and earth, because that is what it is, but remotely earthed back at the substation or even at the power station itself.
What we know as 'earth' then is simply a 'local' earth and often a copper stake driven into the ground. More modern installations connect 'our' 'neutral' and 'earth' together at the meter?!

 

[WatsonJohnG]

Swift have got round this by fitting unswitched sockets
You unplug and then its got to be OK
It surprises me that caravan makers used nice coloured single pole switched sockets rather than cheaper double pole white ones ---or does it

 

[WatsonJohnG]

"
"After the transformer on the post feeding our site blew up, I was talking to one of the guys fixing it, they refer to live and neutral as line and earth, because that is what it is, but remotely earthed back at the substation or even at the power station itself.
What we know as 'earth' then is simply a 'local' earth and often a copper stake driven into the ground. More modern installations connect 'our' 'neutral' and 'earth' together at the meter?! "
I couldn't understanf that when I first saw it in the meter box but it works

The RCD measures difference in current in the live and neutral circuits and trips out if they are out of balance by milliamps
see below
http://www.greenbrook.co.uk/pdf/pbcatpg21-22.pdf
I still like to play safe and check polarity as a converter lead costs little anyway
Belt and braces

 

[GeorgeNeil]

And comming soon there wil be no main RCD fitted to caravans but will be going to a double pole main switch and 2 or 3 circuits of RCBO,s pos of 10 milli amp rated to eliminate nuisence tripping of the pillar RCD.

I can't see this happening as caravan manufacturers are too cost conscious, The idea is good but the additional cost of 3 10ma RCBO's against 1 30ma RCD and 3 MCB's will probably too much for the manufacturers to swallow

In other posts in this thread the double pole MCB is mentioned in reality very few caravans actually have double pole MCB's fitted most are single pole MCB's with a switched neutral

 

[xtrailman]

And comming soon there wil be no main RCD fitted to caravans but will be going to a double pole main switch and 2 or 3 circuits of RCBO,s pos of 10 milli amp rated to eliminate nuisence tripping of the pillar RCD.

I can't see this happening as caravan manufacturers are too cost conscious, The idea is good but the additional cost of 3 10ma RCBO's against 1 30ma RCD and 3 MCB's will probably too much for the manufacturers to swallow

In other posts in this thread the double pole MCB is mentioned in reality very few caravans actually have double pole MCB's fitted most are single pole MCB's with a switched neutral

I have what i assume are double pole Cb's on my 2004 Bailey, i haven't had one fail, so couldn't say.

But i do know that both poles break on a fault, so whats inside isn't really important?

 

[GeorgeNeil]

I can't see this happening as caravan manufacturers are too cost conscious, The idea is good but the additional cost of 3 10ma RCBO's against 1 30ma RCD and 3 MCB's will probably too much for the manufacturers to swallow

In other posts in this thread the double pole MCB is mentioned in reality very few caravans actually have double pole MCB's fitted most are single pole MCB's with a switched neutral

I have what i assume are double pole Cb's on my 2004 Bailey, i haven't had one fail, so couldn't say.

But i do know that both poles break on a fault, so whats inside isn't really important?

What an interesting comment !!!
In a reverse polarity situation a switched neutral will not provide fault protection where a double pole MCB provides both poles with the necessary fault / overload protection
If what is inside isn't really important then why did Electruim (Wylex) recall a lot of Domestic MCB's last year

 

[xtrailman]

i only tour in the UK. Most unlikely to ever have reverse polarity?

Should they be a fault with a reverse voltage, the RCD would detect the current unbalance and trip.
Unless the fault is current overload, then the part of the CB that is not switched will still trip with the CB, as they are mechanically connected.
I haven't got a clue why wylex had a recall, usually its because of a faulty batch?
Perhaps you would like to let us know?