RCBO lights?

[harrisonline]

No. just a new CU. I wanted some extra protection with a toddler running around.

He only gave 3 years as even though he got great readings. He said he had do do that as I had no earth in my light circuit.

 

[harrisonline]

Anyway. I think I will change my MCB's on the lighting circuit to RCBO's. What is the best make to use with my CU (pictured) and what would i gain from having the circuit tested? You don't test a circuit after changing a fuse. If there are any IR problems with the wiring it will just trip wont it? and the RCBO would have been tested in the factory.

 

[sparkyspike]

...what would i gain from having the circuit tested? You don't test a circuit after changing a fuse. If there are any IR problems with the wiring it will just trip wont it? and the RCBO would have been tested in the factory.

You must test a new RCBO. There is no guarantee that a new breaker will work. I fitted a Crabtree RCBO last month and it wouldn't trip under test! It turned out to be faulty. Plus you need to test the whole circuit for nuisance tripping as well as fault triptimes. You need to know that the circuit can be disconnected in 0.4 secs (if required). IR faults won't necessarily trip an RCD.

Plus, you need to check your work. You may have a loose connection, you may have made things worse, not better. How do you know what your disconnection times are if you don't test? You may even make a stupid mistake, like forgetting to reconnect the main earth cable or something. Testing will cover your back for you.

And that's not to mention building regulations and the law.

 

[harrisonline]

If I fitted it myself. Would a spark be prepared to test it for me? I know I could short neutral to earth to test if the RCD worked. But I know that won't tell me how fast it tripped.

 

[sparkyspike]

Possibly. You can always ask. Changing a single MCB to an RCBO just takes a few minutes. You may as well get a spark to do the whole lot for you - fitting and testing.

Unfortunately though, this could be a can of worms!

 

[sparkyspike]

I know I could short neutral to earth to test if the RCD worked. But I know that won't tell me how fast it tripped.

It also wouldn't tell you if it was tripping at the minimum and maximium specified current.

 

[harrisonline]

I purchased some LED bulbs for a kitchen fitting and they lit up (dimly) without any power on!! is that a bad sign?

 

[ericmark]

RCBO is better due to it only taking down the 1 circuit, a RCD will take down everything thats on the RCD side.

An RCBO is an RCD

Regards

Pedantic- An RCBO has the functionality of a RCD but control only one circuit.
So teaching you to suck eggs, would you care to accept that 6 x RCBO's are better than 6 x MCB's on a RCD rail

Sorry no as in at least one place (caravan) this would not be permitted as the RCBO does not switch off all live supplies it only switches off the line. Yes I know there are some specials that will but not the type fitted in normal consumer unit.

Although in many cases it may be better because of tripping problems it can't be done in all cases.

Sorry if I am posting too often. I can't help myself!

I have just been reading through some old posts. And I read that the 17th edition requires un-earthed lighting circuits to be RCD protected.

No! 17th edition does not allow unearthed lighting full stop.

522.6.x covers the cable installation and it will be near impossible to comply with no earth in a cable.

411.3.1.1 Protective earthing
. . . A circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a lampholder having no exposed-conductive-parts and suspended from such a point.

Note it says lamp holder not ceiling rose. The rose must be earthed.

In other words not required in the flex dropping down to each lamp.

But Electrical Safety Council do seem to allow the practice.

416.2.4 ceiling rose is about the only item where you don’t need a tool for access.

And because a lamp holder will normally have a bulb fitted it is about the only socket allowed without a shutter over the pins.

What you are asking is what are the regulations for when you break the regulations? And of course there are non.

It is like asking:- “Is it true if my seat belt is missing I should not exceed 30 MPH.”

Possibly. You can always ask. Changing a single MCB to an RCBO just takes a few minutes. You may as well get a spark to do the whole lot for you - fitting and testing.

Unfortunately though, this could be a can of worms!

Of course it will he can’t sign it off. He was lucky to get board changed and most sparks will consider it is not worth the hassle involved and will just say no.

You may get one who thinks he is doing you a favour but it is apparent it is not a temp fix as already you have know about the fault for a couple of years.

 

[harrisonline]

No! 17th edition does not allow unearthed lighting full stop.

Of course it will he can’t sign it off. He was lucky to get board changed and most sparks will consider it is not worth the hassle involved and will just say no.

It was may 2007. So 16th edition.

Rightly so as time goes by. People think of more and better safety features. But I don't think they meant that anything done in an older way has to be ripped out now as its no longer safe.

Surely that is there for information so people know that there has to be an earth. If you were having an extension built for example and your lighting had no earth you would be expected to have the extension lighting earthed.

The information has to be there or someone could wire the extension without an earth and say "Nothing about earthed lighting in the 17th edition!"

I dont think it is meant to be read as " I can't work on your property if you don't let me earth your lights! otherwise I can't sign it off"

Half the houses in the country have no earth in the lights!

So if I want a part-p electrician to work on my house I have to agree to have my house ripped apart so I get an earth in my lights? like hell!

So basically I have to do all my own electrical work from now on! Or get a non part_p electrician to do it. Thats what part-p is telling me here.

I'll let you know how I get on with the kitchen electrics.

 

[harrisonline]

Phoned my council building regs type dudes today and told them I was thinking about doing some notifiable work in my kitchen.

They said do the work and get an electrician to test/certify it. Fill out a form and post it with the cert and a cheque for £60 and bobs yer uncle. Or they could send out an electrician to check my work/test and certify for £150

So much for notifying them before hand. They don't want to see it till its finished?

 

[hairyben]

I fitted a Crabtree RCBO last month and it wouldn't trip under test! It turned out to be faulty. Plus you need to test the whole circuit for nuisance tripping as well as fault triptimes.

Yeah I've returned a few wylex for failing trip times out-the-box. Same manufacturer as crabtree. Quite concerning.