converting DB to comply with 17th edition

[leep82]

Been to look at a job and the customers consumer unit is split load 100a 100ma time delay rcd, which is acting as the main switch and 80a 30ma rcd. Upstairs and downstairs lights are protected via the 100ma rcd, with the rest of the installation via the 30ma. Ive been asked to do some work on the upstairs lighting circuit including in the bathroom. What i want to do is remove the 100ma rcd and replace it with a 100a double pole main switch and then install an additional 80a double pole rcd.

Obviously i am going to use up an extra two ways in the board, but there is the capacity to do this. Just wondered if i would need to buy any extra kit, additional bus bar or maybe links to feed the new rcd?

 

[Pete999]

Are you an Electrician, or a DIYer

 

[R G]

Whats the earthing arrangements , why not keep the unit as it is and install RCBOs for the lights ??

 

[Leesparkykent]

Is the 100mA RCD time delayed?

 

[R G]

Is the 100mA RCD time delayed?

He says so...

 

[Leesparkykent]

He says so...

Haha oh yeah...skim reading

 

[leep82]

TT system, doing it the way i suggested would still leave spare ways for any future work whilst already having rcd protection in place. Didnt want to go down the rcbo route and make the board look a mess. In an ideal world i would like everything on an rcbo, just seemed easier and tidier to essentially make the board a dual rcd one

 

[Leesparkykent]

TT system, doing it the way i suggested would still leave spare ways for any future work whilst already having rcd protection in place. Didnt want to go down the rcbo route and make the board look a mess. In an ideal world i would like everything on an rcbo, just seemed easier and tidier to essentially make the board a dual rcd one

What make is the board?

 

[leep82]

Another reason for me wanting to go down this route is that i have a 80a 30ma wylex rcd on my van from a recent strip out, its good as new.

 

[leep82]

Wylex DB

 

[Leesparkykent]

Wylex DB

SPSN RCBO jobs a goodun.

 

[Andy78]

What's the reason for getting rid of the 100mA RCD ?

 

[davesparks]

Another reason for me wanting to go down this route is that i have a 80a 30ma wylex rcd on my van from a recent strip out, its good as new.

So put it at the far end of the CU and route the lx circuit that you are working on through it.

 

[Welchyboy1]

Should really be a double pole rcbo with an upfront 100mA rcd

 

[Leesparkykent]

Should really be a double pole rcbo with an upfront 100mA rcd

How come? What's wrong with a single pole switched neutral RCBO? When you have a 100mA S type upfront.

 

[leep82]

What's the reason for getting rid of the 100mA RCD ?

at the minute any problems, nuisance tripping with that and the whole installation goes off

 

[davesparks]

at the minute any problems, nuisance tripping with that and the whole installation goes off

But removing it removes the backup fault protection it provides when the 30mA fails to trip.
By removing it you are making the installation less safe than when you found it.

 

[telectrix]

RCBO all the way, in my book. keep trhe spare RCD for another job.

 

[Kamikaze]

What would be the point of making any changes to the distribution board, since in four months time, it wouldn’t comply again?

 

[telectrix]

What would be the point of making any changes to the distribution board, since in four months time, it wouldn’t comply again?

because it will comply when he makes out the cert. sod next year.