BS 1363 Socket Outlet Switching

Joined
20 Feb 2017
Messages
644
Reaction score
72
Location
Melbourne, Australia
Country
Australia
Although NOT required, most UK BS 1363 Socket-Outlets have a switch for each "Outlet".

Are some, mostly or all of these switches "Double Pole"?
If "some" or "mostly" is the answer, is the inclusion of a "Double Pole" switch an "indication" of the quality of the device?

The reason for this question is that (with a few exceptions) Australian/NZ "Socket-Outlets" are required to have a switch associated with each of them BUT "Double Pole" switches are required only in "Caravans", "Mobile Homes" etc.,
where the temporary connection may be via a wrongly wired flexible connecting cable, with the Line and Neutral reversed.
(https://en.wikipedia.org/wiki/AS/NZS_3112 refers)
 
Sponsored Links
Joined
27 Jan 2008
Messages
19,688
Reaction score
1,895
Location
Llanfair Caereinion, Nr Welshpool
Country
United Kingdom
Some and single and some double pole and some not switched, it is common to use a non switched to supply items like washing machine, oven, tumble drier mounted under counter often with a separate switch above the counter, the use of single pole switching can cause problems with earth - neutral faults, in the UK caravans are a special case, with boats and petrol stations TN-C-S supplies not allowed, so in the main this means TT, so need to be double pole due to being TT, there has been a change I think, Mobile Homes were not considered as caravans, I think that has changed this year.

132.14.2 No switch or circuit-breaker, except where linked, or fuse shall be inserted in an earthed neutral conductor. Any linked switch or linked circuit-breaker inserted in an earthed neutral conductor shall be arranged to break all the related line conductors.
In a TN-S or TN-C-S system the neutral conductor need not be isolated or switched where it call be regarded as being reliably connected to Earth by a suitably low impedance. For supplies which are provided in accordance with the Electricity Safety, Quality and Continuity Regulations 2002, the supply neutral conductor (PEN or N) is considered to be connected to Earth by a suitably low impedance. Amended July 2008

There are a host of referances to neutral and earth, and the electric vehicle seems to have caused problems, never before have I seen it where the earth is switched, the TN-C-S supply seems to be causing a problem, although rare, the PEN can be lost, so we have a problem once outside of the equipotential bonding zone. We are seeing there is a real problem in the garden, or any other area outside the zone, so the rules seem to be changing, I don't have latest edition, and it takes some wading through, and we have seen requirements being clarified, which is a real problem, the BS 7671 has always stated the date when it comes into force, and points out it is not retrospective. That is OK for some thing new, but when it clarifies, then clearly the regulations was there before, just not written in a way people understand, so "Every installation shall be divided into circuits, as necessary, to: (iii) take account of danger that may arise from the failure of a single circuit such as a lighting circuit (iv) reduce the possibility of unwanted tripping of RCDs due to excessive protective conductor currents produced by equipment in normal operation, has shown the RCD was considered as forming a circuit, but since this has been reinforced, and it brings into question is a duel RCD consumer unit complaint.

However "The Regulations are non-statutory. They may, however, be used in a court of law in evidence to claim compliance with a statutory requirement." so since non statutory if we don't comply that in its self is not a crime.
 
Joined
28 Jan 2011
Messages
50,478
Reaction score
3,405
Location
Buckinghamshire
Country
United Kingdom
Although NOT required, most UK BS 1363 Socket-Outlets have a switch for each "Outlet". Are some, mostly or all of these switches "Double Pole"?
If "some" or "mostly" is the answer, is the inclusion of a "Double Pole" switch an "indication" of the quality of the device?
Yes, "some", perhaps "mostly", is probably correct in terms of new sockets today. I wouldn't say it has anything to do with the quality of the device - it's just 'different'. Switched "FCUs" have all (or virtually all) had DP switches for very many years.

I have to say that I have never really understood the point of DP switches in sockets. As a means of isolation, or as a means of prevented connected equipment with N-E faults tripping and RCD they are (functionally) preferable - but that seems a silly argument in the case of a socket, since the ultimate in isolation can be achieved by pulling the plug out of the socket!

Kind Regards, John
 
Joined
28 Jan 2011
Messages
50,478
Reaction score
3,405
Location
Buckinghamshire
Country
United Kingdom
... so in the main this means TT, so need to be double pole due to being TT ...
I presume that you are thinking of BS7671's requirement (still present in Amd3) that isolation must be of 'both live conductors' in the case of a TT installation.

However, as I've just written, that is irrelevant in terms of switches in sockets, since one can always achieve the ultimate in terms of 'DP isolation' by pulling the plug out!

Kind Regards, John
 
Joined
28 Jan 2011
Messages
50,478
Reaction score
3,405
Location
Buckinghamshire
Country
United Kingdom
I seem to remember there is a current limit after which there needs to be a switch, think 32 amp sockets normally switched.
You may be right, but I am personally unaware of any such requirement - if one existed, I would expect it to be in 553.1, but it isn't.

We are surely all familiar with sockets rated at 32A and above which are not switched, aren't we? In fact, I have personally seen very few such sockets which are switched.

Kind Regards, John
 
Sponsored Links
Joined
28 Mar 2004
Messages
9,852
Reaction score
439
Country
United Kingdom
AIUI sockets up to 32A are considered suitable for "functional switching", those above that level are not.

TABLE-2.jpg


It would presumably be up to the designer to determine if functional switching is required and if-so make provision for it.
 
Joined
17 Aug 2010
Messages
2,248
Reaction score
301
Country
United Kingdom
According to that table 32A plug and socket outlets are both suitable for functional switching and not suitable for functional switching.
 
Joined
28 Jan 2011
Messages
50,478
Reaction score
3,405
Location
Buckinghamshire
Country
United Kingdom
AIUI sockets up to 32A are considered suitable for "functional switching", those above that level are not.
Indeed, and that's almost the opposite of eric's suggestion that sockets of 32A and above are 'required' to have switches1

Kind Regards, John
 
Joined
28 Mar 2004
Messages
9,852
Reaction score
439
Country
United Kingdom
I'm assuming the socket outlet itself is what is being discussed in the table and not any associated switch.
 
Joined
28 Jan 2011
Messages
50,478
Reaction score
3,405
Location
Buckinghamshire
Country
United Kingdom
According to that table 32A plug and socket outlets are both suitable for functional switching and not suitable for functional switching.
Indeed, presumably either the "less than or equal to" sign was meant to be "<" or the "greater than or equal to" one was meant to be ">"!

Mind you, whilst it could be just a typo, it might also indicate a lack of thought - I have seen many cases (in many fields) of a pair of "less than or equal to" and "greater than or equal to" statements leaving the "equal to" situation ambiguous!

Kind Regards, John
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Top