EICR coding (C1,C2,C3,N/A)

[gazdkw82]

Just doing some mock exams for the upcoming 2391 course.

Confused on this question as I got it wrong.

Q. If a lighting circuit installed in metal conduit in a shop supplied from a TNS system had no RCD provided for fault protection but achieved disconnection times what would the outcome be on the schedule of inspections.

I put it as a C3. Improveme needed.

The answer has come back as N/A.

Can any explain this?

 

[Deleted member 26818]

Yes.
There is no requirement yet to provide RCD protection for lighting circuits.
The lights themselves do not require RCD protection, and the cables are contained in metal conduit which provides protection from nails and screws.

 

[gazdkw82]

Yes.
There is no requirement yet to provide RCD protection for lighting circuits.
The lights themselves do not require RCD protection, and the cables are contained in metal conduit which provides protection from nails and screws.

Ah (silly sod) because I've been studying the 18th I've convinced myself that rcd on lighting circuits is a requirement.

 

[Ian1981]

Ah (silly sod) because I've been studying the 18th I've convinced myself that rcd on lighting circuits is a requirement.

It is in domestic installations when the 18th edition comes into full effect

 

[buzzlightyear]

http://www.cfecltd.co.uk/files/pdf/17_edition_factsheet_02.pdf

 

[Nigel]

Was the question literally written word for word like that?

 

[gazdkw82]

Was the question literally written word for word like that?

Yes.

Why?

 

[Nigel]

Yes.

Why?

Not enough info in my opinion.

No mention in if the conduit is earthed.

No mention on if it is surface of chased in the wall.

Assuming it is earthed then no code. If it is not earthed then C2 for no earth and if it is chased in the wall with no earth then a C3 for no RCD also.

 

[gazdkw82]

Not enough info in my opinion.

No mention in if the conduit is earthed.

No mention on if it is surface of chased in the wall.

Assuming it is earthed then no code. If it is not earthed then C2 for no earth and if it is chased in the wall with no earth then a C3 for no RCD also.

Yeh I agree

 

[Flanders]

Yes the question is a bit confusing its trying to dissect what they are getting out , For example what part of the schedule are they referring to

RCD(s) provided for additional protection, where required - includes RCBOs (411.3.3; 415.1) then N/A

Adequacy of protective devices: type and rated current for fault protection (411.3) then it would be Pass​

 

[Deleted member 26818]

Doesn’t matter if it’s earthed.
Doesn’t matter if it’s surface or concealed.
Only thing that would mean RCD protection is required, is if it’s part of a circuit of a location containing a bath or shower.
It’s a shop, so that is unlikely.

 

[Flanders]

Doesn’t matter if it’s earthed.
Doesn’t matter if it’s surface or concealed.
Only thing that would mean RCD protection is required, is if it’s part of a circuit of a location containing a bath or shower.
It’s a shop, so that is unlikely.

I thought if your using conduit as mechanical protection it had to be earthed , or does it not because conduit will prevent a screw or nail from Penetration , ( Now there a word for a Friday afternoon )

 

[gazdkw82]

I thought if your using conduit as mechanical protection it had to be earthed , or does it not because conduit will prevent a screw or nail from Penetration , ( Now there a word for a Friday afternoon )

It's still an exposed conductive part

 

[Deleted member 26818]

I thought if your using conduit as mechanical protection it had to be earthed , or does it not because conduit will prevent a screw or nail from Penetration , ( Now there a word for a Friday afternoon )

The options for providing additional protection for cables concealed in walls are:
to bury the cables at a depth greater than 50mm,
to use a cable with an earthed screen,
to use earthed conduit or trunking,
to provide mechanical protection sufficient to prevent penetration by screws and nails,
to run the cables in prescribed routes and provide RCD protection.

 

[Flanders]

The options for providing additional protection for cables concealed in walls are:
to bury the cables at a depth greater than 50mm,
to use a cable with an earthed screen,
to use earthed conduit or trunking,
to provide mechanical protection sufficient to prevent penetration by screws and nails,
to run the cables in prescribed routes and provide RCD protection.

Ok so it has to in an EARTHED conduit system. So conduit must be EARHED
Unless the conduit is sufficient to protection to prevent penestration by screw or nail. Then NO EARTH is required.
Now I would of said that all the metal conduit I have used would stop a screw or nail but is there any metal conduit that could be penertrated?
I

 

[Deleted member 26818]

Ok so it has to in an EARTHED conduit system. So conduit must be EARHED
Unless the conduit is sufficient to protection to prevent penestration by screw or nail. Then NO EARTH is required.
Now I would of said that all the metal conduit I have used would stop a screw or nail but is there any metal conduit that could be penertrated?
I

I have seen some very thin walled conduit whilst working on older installations. Sort of stuff you could literally squash with your fingers.
Nowadays I think light gauge conduit is something only found in places like the USA and Canada, or in the UK when it’s Stainless Steel.
The Galv steel conduit I use has a wall thickness of 3mm, though I understand it is possible to obtain a thickness of only 2mm.
Of course, there is flexible steel conduit (kopex), but that would only be suitable for use at a depth greater than 50mm, or within prescribed routes along with RCD protection.

Upon reflection, the question is probably based on the 18th edition, as it makes reference to ‘circuit’ and goes on to say the installation is non-domestic.
At present, the only circuits which require RCD protection, are those referenced in Part 7 Special locations.
Circuits of a location containing a bath or shower, etc.