Adding to light circuit

[typonaut]

I have a “dull” spot in a corridor, where I want to add an additional light. The light will be a small LED downlighter, at an angle, in ceiling cornice. There is enough space behind the cornice to run the necessary cable (still not absolutely certain I can get a light that is low profile enough). I understand the difference between series and parallel circuits, and will put the new light in parallel with the old one.

However, the bit that is confusing me at the moment is, given the ever changing regulations, whether I can do this myself… or not? If I cannot do this myself, what knowledge or qualification do I need in order to be in a position that I can do it myself?

Just to make another couple of things more obvious: this is in a flat with concrete walls/ceilings/floors, where it isn't really practical to have ceiling lights (because the ceilings are relatively low and routing a cable would mean surface mounted trunking or going through the upstairs flat).

I am confident that the lighting circuit has adequate power, as it was setup for multiple incandescent bulbs (at least 10 bulbs on the circuit) and now has only LEDs - so is probably drawing around 20% of its previous capacity.

 

[ericmark]

Competent person. A person who possesses sufficient technical knowledge, relevant practical skills and experience for the nature of the electrical work undertaken and is able at all times to prevent danger and, where appropriate, injury to him/herself and others. This is a little dated now as Skilled and Competent now combined, but there never has been a fix qualification requirement to be an electrician, although to be a member of a scheme so one can self certify the scheme providers do have a minimum requirement and also annual fee.

Although my own house does not have concrete ceilings, there is an access problem, what I am looking at is lighting track so it looks as if there to allow flexible lighting, but really it is because no ceiling access.

The power is not the only consideration, one of the problems is anything new needs RCD protection, so although old stuff does not need updating, new stuff must comply with current regulations, in real terms we need to make a judgement, I found my consumer unit fitted 2019 is now out of date, type AC RCBO's no longer allowed, I have decided since a TN-C-S supply so the RCD part of the RCBO is secondary protection, and I have 14 of them, that the chance of DC causing a problem at the same time as a fault which should trip the RCBO is unlikely so I have decided not to renew them all. But this is what I have personally decided, some one else could take a different view.

 

[typonaut]

So, if you cannot "self certify" you have to get someone else to inspect the work?

Unfortunately I think a lighting track would not be suitable, because the ceilings are relatively low - I can touch the ceiling without standing on tiptoes.

Looking at the consumer unit I have MCBs on every circuit and an RCCD on four circuits that include the outlet sockets (but not the lighting).

If you are saying that I need to install a new consumer unit in order to put an additional light on an existing circuit, then I think that project is not going to happen! However, you mention DC, and I'm not really considering installing a transformer/low voltage lighting.

Thanks

 

[Murdochcat]

Adding a light and complying with the regs in the OPs case is tricky as anybody who claims to be a spark will be duty bound to point out that this change does require RCD protection for the circuit

 

[flameport]

If you are saying that I need to install a new consumer unit in order to put an additional light on an existing circuit,

Not necessarily. Depends on what consumer unit you have got, and if parts exist for it.

 

[SUNRAY]

Not necessarily. Depends on what consumer unit you have got, and if parts exist for it.

Or fit a post CU RCD unit

 

[typonaut]

So, potentially, one could replace the MCBs with RCDs (RCBOs)?

Or fit a post CU RCD unit

You'd do that on the lighting circuit?

 

[ebee]

You can do that on any circuit.

Once upon a time, not really that long ago, the only way to fit any RCD was pretty much as a separate unit in an enclosure and the use it inline with the tails or use them on the outgoing ways of each circuit you wanted to protect. Then along came consumer units with front end RCDs (RCCBs) built in as the Main Switch. There was even an article in Wiring Matters giving the opinion that a front end or a collective RCD does not clash with the "Each Circuit .... Separate ......." reg requirement (personally, I did not really agree with that stance) but front end RCDs were a very common configuration for quite a long while before splits (some non-RCD circuits and some RCD circuits to dual RCD circuits, when RCBOs started to become readily available they were very expensive, nowadays their price is nearer to the MCBs of a few years back.

I myself am a Front Ender (yes type AC) .

Do I feel unsafe? no, not in comparison to the many rewires of installations with BS 3036 fuses and no RCD no OPD. A little in comparison to todays standards but I leave the updating to the next person in and will advise the accordingly "Yes it would be a good Idea to RCBO therefore change consumer units (one for normal and one for off peak)

 

[SUNRAY]

So, potentially, one could replace the MCBs with RCDs (RCBOs)?

You'd do that on the lighting circuit?

You can do that on any circuit.

Once upon a time, not really that long ago, the only way to fit any RCD was pretty much as a separate unit in an enclosure

It certainly was.

I myself am a Front Ender (yes type AC) .

Me too in several buildings I manage and in one of my rental properties.

Do I feel unsafe?

No