This discussion is locked.

You cannot post a reply to this discussion. If you have a question start a new discussion

New EICR - "No earth bond to some socket boxes: C2"?

Former Community Member over 4 years ago

I have a new EICR which has the observation "No earth bond to some socket boxes: C2".

I have checked continuity between all faceplate mounting screws and the earth of the socket. They are all connected, i.e. the back box is at least earthed by the screw if not with a tail internally (I have not removed the front plates of any sockets). The earth of each socket is connected to the ring.

While it is best practice, is it a requirement of the regulations that a tail is connected internally?

many thanks

0 Sparkingchip over 4 years ago

Alcomax:

The NAPIT Codebreakers, much maligned by some people though a good reference.

If you wonder why it is so maligned, consider the ramifications of applying the following [dis] logic

In the first instance, it is a ring, likely for sockets so 30mA RCD, but aside from that you have put an unnecessary obstacle to negotiate for any person wanting to then apply an alteration or addition to that circuit. Or is this a way of forcing a rewire of that circuit if anyone is considering altering or adding to it?

Back when I did the 16th edition course we did a couple of calculations, when protected by a rewirable fuse it could an issue, when protected by a Type B MCB it may not be such an issue, the book recommends C3 without taking into account the protective device or any other factor, such as the presence of RCD protection which won’t actually reduce the fault current.

The choice is C3, FI or no code. I err on the side of no code when protected by a MCB and a RCD, but C3 is reasonable, particularly if it is protected by a rewirable fuse without RCD protection.

Andy B.
Cancel
Vote Up 0 Vote Down

Cancel
0 UKPN over 4 years ago

This great forum, born out of two long institutions, now fast becoming a graveyard for bogus wiring reports.

Amateur electricians, "code" books, conflicting opinions, "inspectors" too scared to code items other than "2" or "3" because they dont know, and it "covers their a##.

So, 1= C3

2= N/A

3= N/A

4= N/A

Regards, UKPN
Cancel
Vote Up 0 Vote Down

Cancel
0 Former Community Member over 4 years ago

UKPN:

This great forum, born out of two long institutions, now fast becoming a graveyard for bogus wiring reports.

Amateur electricians...

Well, that's me.

When I googled for help on my EICR I was surprised this site came up. I would have expected the IET to be more concerned with debating the finer points of the electronic control of magnetic confinement in a nuclear fusion torus. Of course, I have been extremely grateful for the wise advice I have received here.

I used to ask domestic wiring questions in a Facebook group called "Crap Electrical". Years ago it was a very helpful group but over time it filled up with arrogant sparks waving their manhood about and slagging off diligent DIYers.
Cancel
Vote Up 0 Vote Down

Cancel
0 Sparkingchip over 4 years ago

There used to be a moonlighting DNO electrician that I knew personally who did work cash in hand at weekends to finance his wife’s lifestyle, I used to sit and have lunch with him in the back of his DNO truck whilst on sites where he was jointing cables in the days when the DNO guys had trucks that were proper sheds on wheels with a workshop inside them and a big gas burner that could be used to boil a kettle. Nice chap, but he had one very bad habit in that he used to cut the circuit protective conductors off on lighting circuits, because he didn’t consider that they served any particular purpose.

It’s amazing how entrenched some people can be and still insist on maintaining electrical installation practice that other people accepted was no longer the way to do it thirty years earlier.

When replacing old fuse boards with consumer units I have spent many a happy hour trying to expose enough of the lighting circuit CPCs he cut off to get a connector onto them to extend them to where they are supposed to go to.

Personally when installing sockets and the like I fit an earth fly lead to the box box and usually do it when replacing a fitting if one has not been installed. How many times have you seen live electrical fittings hanging on the conductors connected to them because the fixing screws have been removed to allow a wallpaper or tiling to be tucked behind them leaving the back box unearthed?

Andy B.
Cancel
Vote Up 0 Vote Down

Cancel
0 Chris Pearson over 4 years ago

One thing that is certain is that this forum does not exist to validate installations which may be unsound.

I would also point out that The Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020 were enacted for a purpose.

JPC seems to be doing his best to rectify the situation, but dare I say, at least cost. All the evidence which I have seen is that a complete re-wire is appropriate.
Cancel
Vote Up 0 Vote Down

Cancel
0 UKPN over 4 years ago

What surprises me is why this guy is still on here asking questions on codes that were supposed to be remedied within 28 days ago. and the local council notified. Putting aside he has employed an amateur electrician who doesnt know a C2 from a Fi, and these "defects" didnt need modifying anyway, why hasnt the "inspector" fixed the "potentially dangerous" installation? Alternatively, why not employ a real electrician? Whats next? The forum waits.

Regards, UKPN
Cancel
Vote Up 0 Vote Down

Cancel
0 Sparkingchip over 4 years ago

Regards the size of the CPC in older 2.5 mm twin and earth being 1.0 mm, it doesn’t take much to figure out that the potential issue is the size of the fault current.

So if it TNCS and it looks like there will be a big bang with several thousand amps flowing it’s more of an issue than if it’s TT with a low current of just a few amps.

So there isn’t a set code, it depends on the installation. I have tested sockets in people’s homes by substations with fault currents in excess of 3000 amps and the installations have TT earthing whilst houses further away are TNCS earthed, which I have been told was because the DNO didn’t want any big bang earth faults to occur in these installations.

One such TT installation was within forty feet of the substation transformer and I was actually struggling to get an acceptable Ra on the earth rod I was installing whilst the L/N PSC was massive, I was actually on the point of contacting the DNO to ask if the Tx actually had a decent earth, I had planned to install an upfront 100 mA RCD but couldn’t get the Ra down enough.

Am I going to go a calculation every time? I don’t think so!
Cancel
Vote Up 0 Vote Down

Cancel
0 Sparkingchip over 4 years ago

Around here in a county town PSC tends to be between 700 and 1500 amps, however I understand that in central London and other big cities they are far in excess of this.
Cancel
Vote Up 0 Vote Down

Cancel
0 Sparkingchip over 4 years ago
Cancel
Vote Up 0 Vote Down

Cancel
0 Sparkingchip over 4 years ago

To put the 1.0 mm CPC in a 2.5 mm twin and earth socket ring circuit into perspective, the 30 amp circuit may be protected by a 0.85 mm fuse wire.

So worst case scenario is a spur wired into socket ring close to the fuse board with a high PSC. The maximum PSC for a rewirable fuse board is 1 kA.

If you are doing testing for an EICR and you find a rewirable fuse board, a high PSC and 2.5 mm twin and earth with 1.0 mm all sorts of potential issues should be flagged up, because the earth conductor is only 0.15 mm bigger than the fuse wire.

Andy Betteridge
Cancel
Vote Up 0 Vote Down

Cancel

New EICR - "No earth bond to some socket boxes: C2"?

Community Rules & Guidelines