Wiring up garage lighting

[TJ Anderson]

Thank you.
The simple truth is you are not going to stop people from doing DIY jobs on their own house, particularly if they are confident they understand what they are doing and work in other trades. Wiring the swa to the garage and wiring lights to a garage consumer unit couldnt have been more straightforward - 100% confident about the work I did. With the switch I was concerned that I might short the circuit if I got it wrong; without a ceiling rose I couldnt see a way of avoiding running the switched live to a neutral. This is why I asked the question to qualified trusted tradesmen rather than making a stupid mistake. Many thanks to everyone who replied and especially those who have helped.

You're welcome. Regarding my last..... What do you think about RCBO & RCD though?

 

[Spoon]

Why a 20 amp MCB for a 16 amp socket?

It's to power a single phase table saw. When I had this set up in my old garage it kept tripping on start up. I changed the MCB to a type C with higher amps to account for the surge when it starts up.

100% confident about the work I did

So now you have a 16A socket wired to a 20A circuit..... Interesting....

 

[TJ Anderson]

So now you have a 16A socket wired to a 20A circuit..... Interesting....

It is prob one of the new type fused industrial sockets so it's all cool

 

[Joe]

Why have you got 2 x 30ma d

18th edition RCD back up back up. Discrimination is so 17th Edition you know lol

Why have you got 2 x 30ma devices in series Joe?

The rcbo in the house was just to isolate the circuit from the rest of the house. If the cable gets cut or damaged in the garden, I don't want anything else being affected in the house. I could have fitted another rcd + MCB instead but there wasn't room on the board. The RCD in the garage is for the garage circuits. I didn't see the need to add another main switch in the garage. Is that against regulations?

 

[Joe]

So why a 20 amp now? Do you understand the difference between B & C curves?

No I don't! This is what I have always used with this table saw. From my rudimentary understanding a type C can cope with a surge in power twice as well as a type b!

 

[davesparks]

The rcbo in the house was just to isolate the circuit from the rest of the house. If the cable gets cut or damaged in the garden, I don't want anything else being affected in the house. I could have fitted another rcd + MCB instead but there wasn't room on the board. The RCD in the garage is for the garage circuits. I didn't see the need to add another main switch in the garage. Is that against regulations?

The point is that you have put two RCDs in series which does not comply. It raises the question of why you have provided RCD protection to the SWA distribution circuit which is normally unnecessary?

 

[davesparks]

Purely to keep any moisture out. They are installed inside the garage but my sockets, switch and cu are all waterproof. OTT maybe but I'd rather play it safe

You say you’d rather play it safe but you won’t even pay for an electrician to check the work you have done? This is nonsense, if you wanted to play it safe you would employ a competent electrician.
Instead you have carried out the work yourself and created an installation which, based on what you have said, is non-compliant and dangerous.

 

[Joe]

The point is that you have put two RCDs in series which does not comply. It raises the question of why you have provided RCD protection to the SWA distribution circuit which is normally unnecessary?

Thanks Dave. If it's against regs ill change it.

 

[Joe]

You say you’d rather play it safe but you won’t even pay for an electrician to check the work you have done? This is nonsense, if you wanted to play it safe you would employ a competent electrician.
Instead you have carried out the work yourself and created an installation which, based on what you have said, is non-compliant and dangerous.

Non compliant; fine. I can change it. I can't see that's in any way dangerous though

 

[davesparks]

Thanks Dave. If it's against regs ill change it.

Good, what will you change it to?
What is the EFLI of the distribution circuit?

 

[davesparks]

Non compliant; fine. I can change it. I can't see that's in any way dangerous though

If you cannot see what is obviously dangerous then how can you consider yourself competent?
An OCPD rated higher than the connections on a single point radial is dangerous.
A lighting circuit with no functional switching and relying on the mcb for functional switching is incredibly poor design.

 

[Joe]

So now you have a 16A socket wired to a 20A circuit..... Interesting....

Ok. Again, this how it was set up previously. Can you explain to me then why it's ok to wire 13a sockets up to a 32a circuit?

 

[Joe]

Good, what will you change it to?
What is the EFLI of the distribution circuit?

Looks like I'll need to use another MCB on the distribution board then.
If you think I need a 16a type C for the 16a socket that's easily changed too. Can you explain why its ok to run 13a sockets through a 32a circuit then?
I obviously wouldn't have the first clue about how to calculate the efli of the distribution board and I don't need to. As I said Ill get a qualified electrician to check everything before powering on. Thank you though. You've given me some useful advice

 

[Toneyz]

Non compliant; fine. I can change it. I can't see that's in any way dangerous though

No, but if you want a third party to test and sign it off it needs to be compliant.
If you have a 16A socket fed from radial circuit you want the protective device to be no higher than 16A.

 

[Deleted member 26818]

Deleted.

 

[Pete999]

I didn't ask for advice. I asked if my wiring would work and if there was an easier way. You have advised me to pay for an electrician to do my donkey work though. Thanks for taking the time to reply but Ive explained that I've already done the work. You could save yourself the trouble next time.

Well that's that then.

 

[Pete999]

Thanks for the advice Pete but if I need a 20mm hole drilling through the wall of MY house, a hole jigsawed through the ceiling of MY bathroom and a trench dug through MY garden, I'll be doing that myself thanks.

OK well that's me told then

 

[telectrix]

Can you explain why its ok to run 13a sockets through a 32a circuit then?

because the 13A BS1363 plugs are fused.

 

[Spoon]

As I said Ill get a qualified electrician to check everything before powering on.

I can't see this happening, as you didn't do it for the original install, as the electrician would have commented on the 20A breaker on a 16A socket. This is entirely up to you at the end of the day...

 

[Andy78]

I think everyone is wasting their breath here. The OP has made it clear they will do what they want, and the forum has made it clear that they shouldn't be.
Neither side is likely to change their tack, one through ignorance and stubbornness, the other through an educated and experienced view and stubbornness.
Let's call it a draw.