Changing main RCD AC-type to A-type

[MozMac]

Hi, I'm back in the electrical game after 9 years break so feeling a little rusty! I'm adding an additional socket to a circuit but the main RCD feeding all the circuits in the consumer unit is AC type. Based on this, I believe I have to change this to an A type which is fine but the question is, do I then have to test every individual circuit in the building as I have changed the characteristics of each circuit? This obviously would change an hour job into a job that could take considerably longer, particularly if there are faults on other circuits and of course have cost implications to the customer. Could anyone offer any advice on this please? Many thanks in advance.

 

[westward10]

If you can obtain a compatible RCD this is fine. No I would not check all the other circuits.

 

[Chivers]

Hi, I'm back in the electrical game after 9 years break so feeling a little rusty! I'm adding an additional socket to a circuit but the main RCD feeding all the circuits in the consumer unit is AC type. Based on this, I believe I have to change this to an A type which is fine but the question is, do I then have to test every individual circuit in the building as I have changed the characteristics of each circuit? This obviously would change an hour job into a job that could take considerably longer, particularly if there are faults on other circuits and of course have cost implications to the customer. Could anyone offer any advice on this please? Many thanks in advance.

I'd test the sockets ZS & RCD trip time and lighting. You're quite right it's altered the whole installation but testing a percentage of it should be adequate enough in my opinion.

 

[Risteard]

I'd test the sockets ZS & RCD trip time and lighting. You're quite right it's altered the whole installation but testing a percentage of it should be adequate enough in my opinion.

The trip times are for the RCCB, so testing it once will give you those. They're not circuit specific.

 

[Chivers]

I meant more to do with circuit connection than the RCD as such you'd at least want to make sure things worked before walking away as you may have to undo a bus bar and anything connected to the original AC type.

In an ideal world you'd only need to undo four screws.

 

[littlespark]

like for like replacement. (even though its slightly different)
Just test the circuit with the addition, and the new rcd trip time, as required for the test cert.

If it mattered at all, it would have been already thought of, would be clear cut instruction, and you wouldn't have to ask the question.

 

[MozMac]

I meant more to do with circuit connection than the RCD as such you'd at least want to make sure things worked before walking away as you may have to undo a bus bar and anything connected to the original AC type.

In an ideal world you'd only need to undo four screws.

If you can obtain a compatible RCD this is fine. No I would not check all the other circuits.

The trip times are for the RCCB, so testing it once will give you those. They're not circuit specific.

like for like replacement. (even though its slightly different)
Just test the circuit with the addition, and the new rcd trip time, as required for the test cert.

If it mattered at all, it would have been already thought of, would be clear cut instruction, and you wouldn't have to ask the question.

Hi all, thanks so much for getting back to me. You've all been really helpful, Maurice