Please help, I can't explain to my boss ! RCD protection

[preppar]

Good afternoon gents and ladies.

So I am having an argument, I say if I do any work on nearly any circuit, namely lighting and power, commercial
I have to upgrade protective devices so the circuit would be up to regs and on this case have either RCBO or RCD,
I ask you kindly to help me and tell me am I right or am I not right in saying that ?

Many thanks for your answers.

 

[malcolmsanford]

Good afternoon gents and ladies.

So I am having an argument, I say if I do any work on nearly any circuit, namely lighting and power, commercial
I have to upgrade protective devices so the circuit would be up to regs and on this case have either RCBO or RCD,
I ask you kindly to help me and tell me am I right or am I not right in saying that ?

Many thanks for your answers.[/QUOTE

There are a whole host of regs that I think you and your boss need to get on speaking terms with

Your a trainee so I can understand your not as yet familiar with the regs.

Answer no there is not nearly every circuit that requires RCD protection, but there are quite a few circuits/equipment that do

 

[Spoon]

Do you have a reg book to hand? As Malcolm says, there are exceptions to the rule for using RCD's.
Do you have a specific installation in mind?

 

[malcolmsanford]

As spoon said just a quick 4 that do

Domestic sockets under 20amp
Cable buried in a wall less than 50mm unless certain conditions are met
Agricultural Installations for fire protection (not though 30mA but 300mA)
Telephone Kiosk, bus shelters etc

And also quite a few other special locations

 

[preppar]

Thank you for a prompt answer, i mean nearly all, and we are having an argument ring main, had a mcb protection, one otlet cracked, if it is to be replaced, do you add aditional protection or leave it as it is ?
That is if the new amendment requires RCD.

 

[hightower]

You can do like for like repairs/replacements so long as the circuit is no less safe than before.

 

[preppar]

And what if circuit was 12v 50w dichroic and you change to LED ?

 

[preppar]

Lighting circuit 12V dichroic to be replaced with LED + drivers, at the moment only MCB - overcurent protected

 

[Spoon]

Do you have a reg book to hand mate?
Where are the lights situated?
Check out Section 715 or the regs.

 

[preppar]

Only the green one :/

 

[Deleted member 26818]

To list all the situations where RCD protection would not be required would take too long.
All you really need to know, is that your work has to comply with the REGs, it doesn't matter if the existing wiring does or doesn't.
Replacement of accessories or light fittings would not require RCD protection be provided.

 

[davesparks]

Lighting circuit 12V dichroic to be replaced with LED + drivers, at the moment only MCB - overcurent protected

Lighting circuits don't need RCD protection unless they have cables without earthed metal covering buried less than 50mm deep and are unsupervised or if they are in a special location

 

[Hawk]

Or if it's a TT system

 

[Simonslimline]

Or if it's a TT system

What if the TT system had an Ra low enough to achieve the required disconnection times without the use of an RCD!

It is possible after-all.

 

[davesparks]

Or if it's a TT system

Not necessarily, it's not all that difficult to get the electrode resistance low enough for a 6A MCB to provide fault protection.