Domestic electrics: understand it, and know where to stop

Cue 1 Notifiable versus non notifiable work, sorted into two columns.

AMARA 00:00 Am I allowed to do electrical work in my own house?

NADIA 00:04 Yes, which surprises people, and it is a heavily qualified yes. Part P of the Building Regulations covers fixed electrical installations in dwellings in England and Wales, and some work is notifiable.

AMARA 00:17 Meaning?

NADIA 00:17 Meaning building control has to be involved. A new circuit is notifiable. A consumer unit replacement is notifiable. And work in a special location, which in practice means within the zones around a bath or a shower, is notifiable.

Cue 2 Bathroom zones diagram showing where work becomes notifiable.

AMARA 00:33 And changing a socket?

NADIA 00:34 Not notifiable, on an existing circuit outside a special location. But hear the distinction, because this is where people go wrong. Non notifiable does not mean unregulated. It still has to comply with the standard and it still has to be tested.

AMARA 00:51 So how do I lawfully do notifiable work?

NADIA 00:54 Three routes. Use an electrician registered with a government authorised scheme, who self certifies and notifies for you. Notify building control yourself before you start, pay their fee and let them inspect. Or use a registered third party certifier, which is rare.

Cue 3 Three lawful routes, with the unnotified fourth crossed out and its consequences.

AMARA 01:11 And the fourth route, which is doing it and saying nothing?

NADIA 01:16 Is not a route. And it catches people years later, not at the time. It shows up in a conveyancing search when you sell, it can hold up the sale, and it can invalidate your insurance if there is a fire.

AMARA 01:32 Which route is actually cheapest?

NADIA 01:34 Almost always the registered electrician. People assume notifying building control themselves saves money and it very often costs more, because the fee is substantial and they may require third party testing anyway.

Cue 4 BS 7671 shown as a standard sitting beneath the Electricity at Work Regulations.

AMARA 01:47 Where does BS 7671 fit? People quote it like law.

NADIA 01:51 It is not law. BS 7671, the IET Wiring Regulations, is the national standard. Complying with it is the accepted way of showing you have complied with the Electricity at Work Regulations and with Part P, which are the legal bits.

AMARA 02:07 Does that mean my old wiring is now illegal?

NADIA 02:11 No, and this matters because people get frightened into unnecessary rewires. The standard changes, and an installation that complied when it was built does not become illegal when a new edition lands.

Cue 5 Old but acceptable beside genuinely dangerous, with photographs of each fault type.

AMARA 02:24 Then how do I tell old from dangerous?

NADIA 02:27 That distinction is the most useful thing in this module. Old but often fine: no RCD on every circuit, an older metal consumer unit, sound wiring in pre 2004 colours.

AMARA 02:39 And dangerous?

NADIA 02:40 Rubber or lead sheathed cable, which is pre 1970 and perishes until the insulation literally crumbles off in your hand. No earthing to metal accessories. Scorching or arcing marks at the fuse board. Any sign of amateur additions in a bathroom.

Cue 6 Warm socket and scorched consumer unit as stop signs.

AMARA 02:56 What about the smaller signs?

NADIA 02:58 A socket that is warm to the touch. A burning smell you cannot place. Cracked accessories. Any of those, stop using that circuit and get somebody in. Warm sockets are loose connections, and loose connections are how electrical fires start.

AMARA 03:14 So what is the honest advice?

NADIA 03:16 Learn this properly so you understand your own house, can judge a quote, and can spot something dangerous. Then use a registered electrician for anything notifiable. That is not me being cautious for the sake of it. It is cheaper, it is certified, and it does not surface when you try to sell.

Cue 1 Six step safe isolation sequence, with the second prove highlighted.

AMARA 03:38 If there is one thing in this whole course, what is it?

NADIA 03:42 Safe isolation. It is not a technique, it is a discipline, and it is what keeps electricians alive. Six steps, fixed order, never shortened.

AMARA 03:52 Take me through it.

NADIA 03:54 Identify the circuit. Isolate it at the consumer unit at the correct device. Secure the isolation with a lock off and a label, so nobody switches it back on while your hands are in there. Prove your voltage indicator on a known live source. Test the circuit at the point of work. Then prove your indicator again.

AMARA 04:16 Why prove it twice? That feels like belt and braces.

Cue 2 Failed indicator giving a false dead reading on a live circuit.

NADIA 04:20 It is the most important step in the sequence and it is the one everybody drops.

AMARA 04:27 Explain.

NADIA 04:27 Suppose your indicator fails between the first prove and the test. You put it on a live circuit, it shows nothing, and you conclude the circuit is dead. You have just been given a false negative by a broken instrument. Proving it again afterwards is the only way to know the reading you trusted was real.

AMARA 04:50 What about a neon screwdriver? Everybody's dad has one.

NADIA 04:53 Throw it away. They give false readings from induced voltage, they can fail to indicate a genuinely live conductor, and their whole design puts your body in the current path. Two pole voltage indicator to GS38, and prove it.

Cue 3 Neon screwdriver crossed out beside a GS38 two pole indicator.

AMARA 05:09 Can I not just turn the light switch off?

NADIA 05:12 No, and this is where people get hurt in their own homes. A switch interrupts the line in normal operation. It does not guarantee the fitting is dead.

AMARA 05:24 Why not?

NADIA 05:24 Older installations sometimes have the neutral switched instead of the line, so the fitting is live with the switch off. Then there is two way switching, borrowed neutrals between circuits, shared lighting circuits. A fitting can be fed from somewhere you did not expect.

AMARA 05:42 So isolate at the board.

Cue 4 Switched neutral fitting: switch off, fitting still live.

NADIA 05:44 Isolate at the board, and test at the point of work rather than trusting the label. Consumer unit labels are wrong more often than they are right, especially in a house that has been extended.

AMARA 05:58 Let us do protective devices, because I have never understood the difference.

NADIA 06:03 Then here is the sentence that fixes it. A fuse or an MCB protects the cable. An RCD protects you.

AMARA 06:11 The MCB does not protect me at all?

NADIA 06:14 Not from a shock, no. Its job is to stop the wiring in your walls overheating and catching fire. It will not operate anywhere near fast enough to save a person.

Cue 5 RCD comparing line and neutral current with 30mA leaking through a person.

AMARA 06:26 And the RCD?

NADIA 06:28 It compares the current going out on the line with the current coming back on the neutral. If there is a difference of around thirty milliamps, that current is going somewhere else. Through you, into the earth. It disconnects in well under a second. That device is the difference between a fatal shock and a very unpleasant one.

AMARA 06:51 And an RCBO?

NADIA 06:52 Both, for one circuit. Which is why a modern board with RCBOs does not black out the whole house because a kettle faulted.

AMARA 07:01 Last one. Earthing and bonding. Same thing?

Cue 6 Earthing path back to source beside bonding holding pipes at equal potential.

NADIA 07:04 Different jobs, constantly confused. Earthing gives fault current a low resistance path back to the source so the protective device trips quickly and clears the fault.

AMARA 07:14 And bonding?

NADIA 07:15 Bonding connects the metal things you might touch, incoming water and gas pipes, to the main earthing terminal. Not to carry fault current away, but to hold them all at the same potential, so there is no voltage difference between the pipe and the tap and you standing between them.

AMARA 07:35 So earthing clears it, bonding stops the difference in the meantime.

NADIA 07:40 That is exactly it, and if you remember that one line you are ahead of a lot of people who work on this for a living.