Ask an Electrician anything...

Ask an Electrician anything...

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912 posts

190 months

Monday 13th February 2023
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https://electrical-assistance.co.uk/meter-tail-reg...

Have a read of that lot few examples below

Whilst there is no separate “meter tail regulations”, sections of BS7671 (18th edition wiring regulations) does deal with installation of cables, of which the meter tails must also comply.

A common installation method with meter tails is to run then between an external meter cabinet, through the cavity, into the consumer unit through the rear of the board.

Following the meter tail regulations to the tee would frown on this installation method as the cables being within the cavity is not a recognised installation method as per BS7671.

I’m not suggesting you start recording that on EICRs as the simple fact is, it presents no apparent risk to the cable.

steve-V8s

2,901 posts

248 months

Tuesday 14th February 2023
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Should an external oil boiler have a dedicated supply from the consumer unit or can it run from a spur off the ring ?

Jeremy-75qq8

1,014 posts

92 months

Tuesday 14th February 2023
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Do current electric regs ( sockets 450mm off the floor ) make floor mounted sockets ( under a desk ) outside of regs ?

Ganglandboss

8,307 posts

203 months

Tuesday 14th February 2023
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Jeremy-75qq8 said:
Do current electric regs ( sockets 450mm off the floor ) make floor mounted sockets ( under a desk ) outside of regs ?
That falls under building regs, Part M. The regs specify a height range for wall mounted socket outlets, but do not prohibit the use of floor sockets.

AW10

4,436 posts

249 months

Tuesday 14th February 2023
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steve-V8s said:
Should an external oil boiler have a dedicated supply from the consumer unit or can it run from a spur off the ring ?
How much does it draw? If only a couple of amps a fused spur is the norm.

steve-V8s

2,901 posts

248 months

Tuesday 14th February 2023
quotequote all
AW10 said:
steve-V8s said:
Should an external oil boiler have a dedicated supply from the consumer unit or can it run from a spur off the ring ?
How much does it draw? If only a couple of amps a fused spur is the norm.
It is not the current but the fact it is outside. Normally I seem to recall an outside socket or an out building must be run run off a separate circuit.

dhutch

14,388 posts

197 months

Tuesday 14th February 2023
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steve-V8s said:
AW10 said:
steve-V8s said:
Should an external oil boiler have a dedicated supply from the consumer unit or can it run from a spur off the ring ?
How much does it draw? If only a couple of amps a fused spur is the norm.
It is not the current but the fact it is outside. Normally I seem to recall an outside socket or an out building must be run run off a separate circuit.
No, there is no requirement for this that I know of.

New outdoor sockets I think have to be RCD protected now, but doubt the would extend to a feed to a boiler.
It might be prudent to have a double pole isolator (live and neutral) but most switched fused connection units (SW FCU) are dp.


ccr32

1,970 posts

218 months

Wednesday 15th February 2023
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New question (unless it has been asked before on the preceding 60 pages and I have missed it) - new LED spotlights have been put up to replace an old pendant light. These LED spotlights (LAP ones from screwfix) have a L+N in, and a L+N out on each light, but no earth terminal.

The spotlights have been daisy chained together using 1.5mm T&E, but aside from the feed in to the room/switch/first spotlight and out to the next room, the earth’s are not connected to each other from spotlight to spotlight.

Is this a problem? Should I pull the lights out and connect all the earth’s together?

Based on my limited understanding, this won’t cause a continuity fault on the consumer unit as the light circuit it is on is a radial, so earth wise the the first light is effectively the end of the line; the risk I guess is if something were to be drilled/screwed up into the ceiling and a cable, there is no earth protection other than to the first light - right?

dhutch

14,388 posts

197 months

Wednesday 15th February 2023
quotequote all
ccr32 said:
New Is this a problem? Should I pull the lights out and connect all the earth’s together?
Not the end of the world and cutting off the earth is common, but better is the joint them all together and back to earth, which avoids and risk of it picking up stray voltage. Cutting off earth's also prevents using them in the future.

Not a spark. Don't know what regs say formally.

ccr32

1,970 posts

218 months

Wednesday 15th February 2023
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Another question - my builder LOVES plasterboard screws, and having just put a board up behind which I know lives some electric cables, I am paranoid he may have nicked a cable with one of the eleventeen million screws he’s put in the board.

No faults or tripping the RCD, but I’d rather be certain before the wall is plastered.

There is a wago junction box under the floor leading to the cables in the wall. If I turned off the power at the consumer unit then used a multimeter to check continuity between each cable in the wago box (L, N and E) and each of the screws in the wall, will this tell me if he has caught a cable with one?

Jakg

3,463 posts

168 months

Wednesday 15th February 2023
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dhutch said:
ccr32 said:
New Is this a problem? Should I pull the lights out and connect all the earth’s together?
Not the end of the world and cutting off the earth is common, but better is the joint them all together and back to earth, which avoids and risk of it picking up stray voltage. Cutting off earth's also prevents using them in the future.

Not a spark. Don't know what regs say formally.
I would say they should be joined - if you drill through a cable with a disconnected earth, the RCD isn't going to trip...

AW10

4,436 posts

249 months

Wednesday 15th February 2023
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ccr32 said:
Another question - my builder LOVES plasterboard screws, and having just put a board up behind which I know lives some electric cables, I am paranoid he may have nicked a cable with one of the eleventeen million screws he’s put in the board.

No faults or tripping the RCD, but I’d rather be certain before the wall is plastered.

There is a wago junction box under the floor leading to the cables in the wall. If I turned off the power at the consumer unit then used a multimeter to check continuity between each cable in the wago box (L, N and E) and each of the screws in the wall, will this tell me if he has caught a cable with one?
He should be screwing the screws into wood, not free air where he might find a cable!

Your test should work providing the coating on the screws is electrically conductive - easy enough to check.

silentbrown

8,832 posts

116 months

Tuesday 14th March 2023
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Our EICR has flagged the lack of RCD on a socket ring circuit with a C2 "Unsatisfactory".

The EICR notes "older installations designed prior to BS7671:2008 may not have been provided with RCDs..." - As our installation is ~30 years old, does this imply it shouldn't have got a C2?




dhutch

14,388 posts

197 months

Tuesday 14th March 2023
quotequote all
Not a spark. But how much does it matter what's it's coded as?

It's far from great, and should be a reasonably easy to rectify.

Ganglandboss

8,307 posts

203 months

Tuesday 14th March 2023
quotequote all
silentbrown said:
Our EICR has flagged the lack of RCD on a socket ring circuit with a C2 "Unsatisfactory".

The EICR notes "older installations designed prior to BS7671:2008 may not have been provided with RCDs..." - As our installation is ~30 years old, does this imply it shouldn't have got a C2?



Are the sockets likely to serve hand-held electrical equipment outdoors, or located in a room containing a shower or bath? If not it's a C3.

silentbrown

8,832 posts

116 months

Tuesday 14th March 2023
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Ganglandboss said:
Are the sockets likely to serve hand-held electrical equipment outdoors, or located in a room containing a shower or bath? If not it's a C3.
Cheers. No, they aren't, unless I start running extension cords out of a window...

There's a couple of other C2s to attend to , as I suspect having an "Unsatisfactory" rating may not help with insurance?.

(BTW, it's taken the sparky NINE MONTHS from the date of inspection to issuing the EICR. Is this a record? )


dhutch

14,388 posts

197 months

Tuesday 14th March 2023
quotequote all
silentbrown said:
Cheers. No, they aren't, unless I start running extension cords out of a window...
... Depending on what the alternative if, that sounds like a yes to me!

Slightly tongue in cheek, but do you have any RCD protected sockets? Near the back door?

silentbrown said:
(BTW, it's taken the sparky NINE MONTHS from the date of inspection to issuing the EICR. Is this a record? )
Given the onea I've had have been same day, something had gone wrong there!



Sheepshanks

32,757 posts

119 months

Tuesday 14th March 2023
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silentbrown said:
There's a couple of other C2s to attend to , as I suspect having an "Unsatisfactory" rating may not help with insurance?.
Just normal household insurance?

silentbrown

8,832 posts

116 months

Tuesday 14th March 2023
quotequote all
dhutch said:
silentbrown said:
Cheers. No, they aren't, unless I start running extension cords out of a window...
... Depending on what the alternative if, that sounds like a yes to me!

Slightly tongue in cheek, but do you have any RCD protected sockets? Near the back door?
Upstairs sockets and extension sockets are all on the RCD side of the CU, as is the spur to the garage. It's just lights and one ring that isn't (plus the cooker, which has a switch+13A socket for the extractor fan). The sockets I use for any work outside are all on the RCD side.






ruggedscotty

Original Poster:

5,626 posts

209 months

Tuesday 14th March 2023
quotequote all
Ganglandboss said:
silentbrown said:
Our EICR has flagged the lack of RCD on a socket ring circuit with a C2 "Unsatisfactory".

The EICR notes "older installations designed prior to BS7671:2008 may not have been provided with RCDs..." - As our installation is ~30 years old, does this imply it shouldn't have got a C2?



Are the sockets likely to serve hand-held electrical equipment outdoors, or located in a room containing a shower or bath? If not it's a C3.
EICR C2 meaning

Taking one step down, EICR C2 means that something on your installation is potentially dangerous. That could be, for instance, a lack of reliable earthing. Over time, that issue could worsen and lead to a shock risk.

As a result, C2 EICR codes require urgent remedial action. You may be able to continue using your system in the meantime, but you should arrange for repairs to be made as soon as you can. Like a C1 code, any issues categorised as C2 will mean the EICR is unsatisfactory until action is taken.

EICR C3 meaning

Moving onto EICR C3, this code means that improvements are recommended for your electrical installation. An example could be wiring that doesn’t meet the latest regulations, but that isn’t a risk in itself.

To be clear, no danger is present and there is no typical sequence of events that could lead to someone accessing live wires. As a result, EICR certificates can still be satisfactory when C3 issues are identified.

All that said, it’s best to have C3 issues rectified to improve the safety of your electrical installation and avoid more expensive issues developing over time.

Thing here is who is making an assumption without having facts...

RCD For Fault Protection

Certain types of installation earthing arrangement (TT mainly) produce external loop impedance figures which are way over the maximum allowed by BS7671 in order to trip in the specified time.

As such these installations need an RCD in order to meet the tripping times, due to the extreme sensitivity of an RCD to low level earth faults.



This can take the shape of an ‘up-front’ RCD, which is often time-delayed on older installations to allow some level of discrimination between up front RCDs and those fitted to final circuits. Alternatively a modern RCBO equipped board can cover each circuit with it’s own 30mA earth fault proptection.

If, when inspecting an installation, you determine that it is of a TT earthing arrangement, then you must ensure that each circuit has some form of RCD protection to cover the much higher Earth Fault Loop Impedance encountered here.

If any circuit does not have an RCD then this must be recorded as a C2 – POTENTIALLY DANGEROUS as an MCB or fuse will not trip in the required time leaving items potentially dangerously live.

No RCD on socket outlets

RCDs have been a requirement for virtually all socket outlets under BS7671 for quite some time now.

When completing EICRs there are 2 particular inspections which you need to judge the installation on.
Sockets serving mobile outdoor equipment

The first is inspection ??.?? which relates to “socket outlets <32A which are used to supply mobile outdoor equipment”. In this inspection you need to consider what is going to be plugged into the socket itself.

Obviously anything electrical used outside, where the user can be in contact with “true” earth, creates much more of a risk to safety.

For domestic inspections, this would be outdoor sockets, garage sockets or anything of that nature. We would consider this to also apply to household sockets on the ground floor where items can be plugged in with an extension lead.

How many times have you seen a lawnmower plugged into an extension lead through the window?

There have been a couple of instances of people getting fatal electric shocks when cutting through lawnmower cables where there has been no RCD on the socket.

In commercial EICRs, expect to be looking for sockets which have a reasonable expectation they could be used to supply portable equipment outdoors. This could be 13A sockets, or even 16/32A sockets on 3 phase.

IF they are not for a specific piece of equipment and there is a risk that portable outdoor equipment could be plugged in, you must code appropriately on the EICR.

According to Best Practice Guide 4, any socket outlet which is expected to supply mobile outdoor equipment should be coded a C2 – POTENTIALLY DANGEROUS.

This answers what EICR code for no RCD for this particular inspection, but what about the others?

All Socket Outlets

The 2nd inspection covers the remainder of the sockets (ie: those no expected to serve mobile outdoor equipment)

Inspection ??.?? is basically covering all socket outlets of under 32A, wherever they may be and whatever they may serve.

In domestic settings it would be any upstairs sockets, it could be a flat above ground floor (where extension leads would not be expected to be strung out the window) or else sockets that are intended to serve single items (could be behind a washing machine for example).

In a commercial setting, again, this is just any socket that would not be expected to serve anything outdoors.

This one is pretty self explanatory, the socket is either protected by an RCD or not. So, What EICR code for no RCD on all socket outlets?

The risk is slightly less on sockets that do not have a potential to supply mobile outdoor equipment, and hence BPG4 recommends a C3 – IMPROVEMENT RECOMMENDED would be the appropriate EICR code for this instance.

SUMMARY...

TT installation - No RCD is a C2

TN-C TN-CS Installation - No RCD and possibility of sockets being used to supply external to house... its a C2

TN-C TN-CS Installation - No RCD and No possibility of sockets being used to supply external to house... its a C3

https://voltacompliance.com/news/eicr-codes-explai...

https://electrical-assistance.co.uk/what-eicr-code...