Permanent vs. switched live

[Roflcopter]

Morning all,

Straight to the question - in a one-way switch, does it matter if the permanent live and switched live connections are not the right way round?


I'm shifting a light switch before redecorating a bedroom. I've dropped new cable for the new switch location. To save time I could just cut into the old cable in the loft and connect it to the new cable drop, but I wouldn't be able to tell which wire was permanent live and which one was switched (the cable is twin red and earth)

If it's important for the permanent live to be in the right place then I'll run new cable to the ceiling rose.

Cheers,

Chris.

 

[Spark123]

If it isn't much bother, it will probably be worth replacing the whole length of cable from the ceiling rose anyway. You should sleeve the blue conductor brown to say it is being used as a switch wire, you might also need one of those wiring to two versions of BS7671 labels on your CU.

 

[ban-all-sheds]

Morning all,

Straight to the question - in a one-way switch, does it matter if the permanent live and switched live connections are not the right way round?

No.

I'm shifting a light switch before redecorating a bedroom. I've dropped new cable for the new switch location. To save time I could just cut into the old cable in the loft and connect it to the new cable drop, but I wouldn't be able to tell which wire was permanent live and which one was switched (the cable is twin red and earth)

That implies that you don't have a multimeter.

In which case you should be doing nothing with electricity except using it.

Do you bang nails in with the heel of a shoe because you don't own a hammer?

Do you use the point of a knife blade for screws, because you don't own a screwdriver?

Equip yourself with the appropriate tools before doing things.

 

[ColJack]

run it back to the ceiling rose..

this will do 2 things..

1. remove the need for a junction box that you would have to leave accessible for testing at regular intervals.
2. prevent future confusion when you find brown / blue at the switch and twin red leaving the light..

oh, and we'll all assume that the reason you NEED to change the cable is besause you have damaged it inadvertantly wilst decorating ( otherwise this is notifiable under part P of the building regulations.. )

 

[jossper]

I've found cables to be much more prone to damage since Jan 2005.
Must be something to do with global warming (everything else seems to be) or the phase of the Moon in Uranus or something.

Happy Christmas all,

Paul

 

[Roflcopter]

Thanks for the replies, I'll just put in a new run of cable to the rose while the insulation is out of the way.

Merry Xmas

 

[Barsteward]

oh, and we'll all assume that the reason you NEED to change the cable is besause you have damaged it inadvertantly wilst decorating ( otherwise this is notifiable under part P of the building regulations.. )

No it isn't.

 

[ColJack]

go on then, tell me why it isn't notifiable that he's changing perfectly good cable?

if that is the case, i can rewire my house from the first and last socket on a ring, and from the first light on the radial...

 

[Barsteward]

go on then, tell me why it isn't notifiable that he's changing perfectly good cable?

if that is the case, i can rewire my house from the first and last socket on a ring, and from the first light on the radial...

I suggest you read up on Part P then.

He ain't working in a notifiable area.
Still has to comply with IEE Regs mind

 

[ColJack]

as soon as you set foot inside the front door you're in a notifiable area....

it's just that some areas you can do certain things without notifying, and some specialist locations you can't even fart without notifying... ( ok that's and exaggeration )

The requirements of this Part apply only to electrical installations that are intended to operate at low or extra-low voltage and are -

(a) in a dwelling;

(b) in the common parts of a building serving one or more dwellings, but excluding power supplies to lifts;

(c) in a building that receives its electricity from a source located within or shared with a dwelling; or

(d) in a garden or in or on land associated with a building where the electricity is from a source located within or shared with a dwelling."

this is the exact text from the statutory instrument ( ie the law itself )

SCHEDULE 2B
Regulation 12(5)



DESCRIPTIONS OF WORK WHERE NO BUILDING NOTICE OR DEPOSIT OF FULL PLANS REQUIRED


1. Work consisting of -


(a) replacing any socket-outlet, control switch or ceiling rose;

(b) replacing a damaged cable for a single circuit only;

(c) re-fixing or replacing enclosures of existing installation components, where the circuit protective measures are unaffected;

(d) providing mechanical protection to an existing fixed installation, where the circuit protective measures and current carrying capacity of conductors are unaffected by the increased thermal insulation.


2. Work which -



(a) is not in a kitchen, or a special location,

(b) does not involve work on a special installation, and

(c) consists of -


(i) adding light fittings and switches to an existing circuit;

(ii) adding socket outlets and fused spurs to an existing ring or radial circuit; or

(iii) installing or upgrading main or supplementary equipotential bonding.



3. Work on -



(a) telephone wiring or extra-low voltage wiring for the purposes of communications, information technology, signalling, control and similar purposes, where the wiring is not in a special location;

(b) equipment associated with the wiring referred to in sub-paragraph (a).


4. For the purposes of this Schedule -



"kitchen" means a room or part of a room which contains a sink and food preparation facilities;

"special installation" means an electric floor or ceiling heating system, a garden lighting or electric power installation, an electricity generator, or an extra-low voltage lighting system which is not a pre-assembled lighting set bearing the CE marking referred to in regulation 9 of the Electrical Equipment (Safety) Regulations 1994[14]; and

"special location" means a location within the limits of the relevant zones specified for a bath, a shower, a swimming or paddling pool or a hot air sauna in the Wiring Regulations, sixteenth edition, published by the Institution of Electrical Engineers and the British Standards Institution as BS 7671: 2001 and incorporating amendments 1 and 2."

and this is the exact text from schedule 2B of the same statutory instrument..

as you can see, baring work in special locations, replacing damaged cables is not notifiable.. there is no mention of replacing good cables though, so we must assume that it's notifiable since it is not expressly mentioned as being non-notifiable..

 

[Barsteward]

You assume wrong.
The OP can carry on without worry. IEE compliant and he's fine.
http://www.planningportal.gov.uk/uploads/br/electrical_safety.pdf

 

[ColJack]

not mandatory and only their interpretation of the law..

same applies for the "approved document".. guideline only and not mandatory..

 

[Spark123]

I'd have thought non-notifiable too - it could be argued he is adding a switch to an existing circuit after removing the original one.

 

[ebee]

go on then, tell me why it isn't notifiable that he's changing perfectly good cable?

if that is the case, i can rewire my house from the first and last socket on a ring, and from the first light on the radial...

I suggest you read up on Part P then.

He ain't working in a notifiable area.
Still has to comply with IEE Regs mind

No it does not need to comply with IEE Regs

 

[securespark]

:
Must be something to do with the phase of the Moon in Uranus

Hey! My anus is pretty big, but you can't get the moon in there!!