Coding for lack of 30ma rcd protection - TT system

[LeeBurns1979]

I’ve had a disagreement with a colleague on this. Installation has 100ma rcd main switch.
Some circuits (5) on this side and further 4 on the
30ma rcd side.

what is the coding for this?

 

[telectrix]

C3, as in that the circuits not protected by 30mA RCD could be improved to increase safety. wouldonly be C1 or C2 if immediate or potential danger present (respectively).

 

[davesparks]

It depends on what the circuits which don't have 30mA protection are, you need to supply more information.

Without further information I would say no code unless something you haven't told us would mean these circuits require 30mA protection. If you at least specified the basic type of installation such as domestic or non-domestic it would help massively.
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C3, as in that the circuits not protected by 30mA RCD could be improved to increase safety. wouldonly be C1 or C2 if immediate or potential danger present (respectively).

Why a C3? They haven't yet told us anything that suggest these circyits require 30mA protection.

 

[telectrix]

It depends on what the circuits which don't have 30mA protection are, you need to supply more information.

Without further information I would say no code unless something you haven't told us would mean these circuits require 30mA protection. If you at least specified the basic type of installation such as domestic or non-domestic it would help massively.
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Why a C3? They haven't yet told us anything that suggest these circyits require 30mA protection.

i assume (perhaps wrongly) that OP is referring to a domestic install, probably to 16th Ed., in which case 30mA RCD protection to cables in walls blah, blah and lighting circuits, maybe unprotected circiuts in a bathroom, would be improved by fitting 30mA RCD protection, so a C3 for improvement recommended.

 

[westward10]

Might help if people used the correct terminology, fault protection and additional protection.

 

[LeeBurns1979]

C3, as in that the circuits not protected by 30mA RCD could be improved to increase safety. wouldonly be C1 or C2 if immediate or potential danger present (respectively).

Thanks I’ve always put as c3 but colleague said C2 as it’s a TT System. Could not see that anywhere

 

[davesparks]

Thanks I’ve always put as c3 but colleague said C2 as it’s a TT System. Could not see that anywhere

You still haven't explained why it needs 30mA protection at all?

Is it domestic? Are they socket circuits? Are there cables buried <50mm? Are they lighting circuits?

 

[James18288]

Guessing at domestic install? Also going to assume that TT the Zs max have been exceeded. (C3 411.3.2.2)
However a 100ma RCD is provided for fault protection and A 30ma RCD for fault/additional protection.
I would code it as C3 if it is what I’m thinking of, a domestic install to the 16th edition. Most likely because of a lighting circuit not having additional protection at 30mA (411.3.4)
In my opinion, it’s only a C2 if no RCD is provided for fault protection on a TT system (411.5.2).

 

[Mark Wright]

Probably depend when it was built and if there's no RCD then it usually required equipotential bonding, earthed conduit for wires in walls under 50mm and all that.
I don't think it would meet current Regs would it all circuits require RCD protection and 100ma is more protection of fire?(is that right) not electric shock.