RCCB as main switch?

[Noob2013]

Hi all,

I have been to a property where the tails come out of the meter and into an RCCB which then feeds the main switch of the consumer unit. All circuits are protected by MCBs.

If I'm adding a new circuit, is it best put in an RCBO instead of an MCB?

Thanks

 

[Guest77]

Thank you.

So if the customer would not pay for that, and it was a time delayed rccb, could a new circuit not have an rcbo so it is protected?

Noob as you are an apprentice should you be doing this work?

 

[Noob2013]

Noob as you are an apprentice should you be doing this work?

I'm just getting a head start of the situation so I look good ☺

 

[ipf]

It will have a 'S' in a square.

But it if this is installed this will not give your circuit appropriate RCD protection.

whole DB change is what I would recommend.

Not even seen the job and pushing for a db change?

 

[Guest77]

I'm just getting a head start of the situation so I look good ☺

Ah I see, you want to impress your mentor then?

 

[Guest125]

Thank you.

So if the customer would not pay for that, and it was a time delayed rccb, could a new circuit not have an rcbo so it is protected?

Yes you will need to RCBO it. If the main is time delayed you will achieve the required discrimination between the RCBO & the RCCB.

 

[davesparks]

There should not be a 'front end' RCD installed at all. Circuits should be separated so that if a fault occurs the whole installation does not trip.

Your crystal ball is obviously working better than mine! I can't quite see what the earthing system is or what rating that up front RCD is.

 

[Guest125]

Not even seen the job and pushing for a db change?

Come on. It would be the best thing to do.

 

[Guest125]

Your crystal ball is obviously working better than mine! I can't quite see what the earthing system is or what rating that up front RCD is.

I am going on the info I have. As in my signature. Everything I say the installer should be happy within their own mind that it is correct.

 

[Guest77]

Not even seen the job and pushing for a db change?

yup, I was thinking the same, I recommend all old aged pensioners in his area bolt their doors tight.

 

[TJ Anderson]

Yes you will need to RCBO it. If the main is time delayed you will achieve the required discrimination between the RCBO & the RCCB.

As I posted before, It may be a 30ma RCD upfront already, he has not stated rating.

 

[Guest125]

yup,I was thinking the same, I recommend all old aged pensioners in his area bolts their doors tight.

Are you implying something deary?

 

[Guest125]

As I posted before, It may be a 30ma RCD upfront already, he has not stated rating.

I know but we were specifically talking about if the RCCB is time delayed. In this case it would not give his new circuit the required protection so a 30mA non time delayed RCBO will be required.

 

[TJ Anderson]

I know but we were specifically talking about if the RCCB is time delayed. In this case it would not give his new circuit the required protection so a 30mA non time delayed RCBO will be required.

You can't get 30ma time delayed RCD or RCBO. He needs to say what he has got.

 

[ipf]

Come on. It would be the best thing to do.

Why change? What earthing system?

 

[Simlec]

Yes Noob you should not have 2 of the same mA RCDs in line, unless your RCCB is 100mA & time delayed.
As you have not given a mA for the RCCB which would normally be on the front, are you mistaking it for a ELCB?
You may need to take a pic of it so members can check.

 

[ipf]

Are you implying something deary?

Says it all....if in doubt, do 'em!!

 

[Guest125]

You can't get 30ma time delayed RCD or RCBO. He needs to say what he has got.

Yes you can.

 

[TJ Anderson]

Yes you can.

Where? Think you will be looking a while

 

[JD6400]

Yes you will need to RCBO it. If the main is time delayed you will achieve the required discrimination between the RCBO & the RCCB.

From the description , and without looking at it !
I would say that the installation is likely to be TT , hence the up front rcd ( probably an 100mA S type ) so why or how could it possibly be failing any regs if the new circuit was to be just installed on a new rcbo ( even then if needed ? ) , instead of a whole new board !?

 

[telectrix]

Yes you can.

find me one!

 

[Guest77]

It may well be one of these chuckle, and the OP is confused.

 

[Guest125]

From the description , and without looking at it !
I would say that the installation is likely to be TT , hence the up front rcd ( probably an 100mA S type ) so why or how could it possibly be failing any regs if the new circuit was to be just installed on a new rcbo ( even then if needed ? ) , instead of a whole new board !?

My point was the opposite. To not install a MCB but an RCBO.

 

[davesparks]

You can't get 30ma time delayed RCD or RCBO. He needs to say what he has got.

Can't you?

 

[Guest125]

find me one!

And when I do?

 

[Simlec]

Yes you can.

Where would you use one?
I know where you find them, next to the rocking horse sh*t lol

 

[telectrix]

And when I do?

shove it up your **** :49:

 

[Guest125]

My point was if he installs a new circuit to a board which has a RCD main switch (and doesn't need it) then in affect he will be making the existing circuits worse by adding to the problem of one RCD protecting the whole installation. I know it is not clear cut and is only my interpretation so I think a board change would ensure all the new work is compliant.

 

[JD6400]

find me one!

I had this about 2 years ago , someone on here had found one on fleabay just to prove a point . :dunce2:
Despite it being from some knock off 3rd world importer , I still had to go to the trouble of explaining why it was as much use as ---- on a bull !

 

[davesparks]

Where? Think you will be looking a while

Well for a start a simple adjustable RCD will give you tripping currents from 10mA up to 1A (or more) and time delays of 0.1S up to 10S (or more)

 

[TJ Anderson]

Can't you?

Not that I am aware, have you?