Socket too low but cable to short to move.

[JohnW2]

That is a good point and will apply to nearly every thread - quite often it is mentioned. Should we have a list of tests under every post.

Indeed. I'm not sure whether the comment related to a fault in the extension of the "earth wire", or the possibility that the earth to the socket (in its original position) was already deficient. If the latter, then the hazard would obviously have existed even if the socket had not been moved.

As always the question which arises is 'how far should one go with that list?'. If there is a perceived need to test the effectiveness of the earth whenever 'it happens' that some minor work has been done on the circuit, should one also test the insulation resistance of the cable and the functioning of the circuit's RCD etc. at the same time? ... and is replacing the lamp/bulb in a Class I light fitting really all that different in this respect from moving a socket a few inches - so does the earthing etc. need to be tested whenever the lamp/bulb is changed?

Kind Regards, John

 

[mikes12]

That's not really necessary. One cable from connectors to socket will suffice, i.e. three conductors in each L and N connector.
All earths must be connected, i.e. three wires in existing box then the new socket and box(if metal).

I was looking for some other advice and stumbled on this post, so sorry for bumping a 2 year old thread. I'm not sure that's good advice.

If they use 2.5mm to spur from a ring, and connect a twin outlet at the end of the spur, then the cable won't be rated properly. It has a max of 24A, whereas a twin socket is rated at 26A.

2.5mm is only rated at 32A when in a ring circuit.

They should use 4mm for a spur, or use a fused outlet.

Also, if you break into a ring, then strictly speaking, I would expect that to be notifiable work, whereas I would expect the spur isn't notifiable, unless it is in a special location.

I'm not part P qualified, but I think I know the basics.

 

[Taylortwocities]

They should use 4mm for a spur, or use a fused outlet.

Also, if you break into a ring, then strictly speaking, I would expect that to be notifiable work, whereas I would expect the spur isn't notifiable, unless it is in a special location.

I'm not part P qualified, but I think I know the basics.

You obviously don’t know the basics then. Read BS7571 especially the appendix 15 relating to final circuits.
2.5mm is ok for a spur from a ring final.
Breaking into a ring is not notifiable work.
Ps. A twin socket is only rated at 20amp!

 

[mikes12]

You obviously don’t know the basics then. Read BS7571 especially the appendix 15 relating to final circuits.
2.5mm is ok for a spur from a ring final.
Breaking into a ring is not notifiable work.
Ps. A twin socket is only rated at 20amp!

The BS standard if I recall says 20A for 4 hours, but I was talking about what I was taught when I did electrical training long before Part P came in.

What normally happens is people spur off spurs, effectively creating radial circuits. No one sticks to the rule of only a single socket (twin or single) on the spur. Therefore it is safer to use 4mm. That's what I was taught, but then, at that time, there was a rule on the number of spurs you were allowed as well. I think even that rule has gone...

Also, if the OP were to somehow break the ring at that point, then it could create a condition where parts of the ring were overloaded as well. Hence, i thought you would have to get an electrical test on the circuit after the work was completed. Not notifiable, but still should be tested properly.

Anyhow, there are so many rules these days, I just get a qualified electrician in to do the work and test.

 

[winston1]

I'm not part P qualified, but I think I know the basics.

Quite. There is no such thing as part P qualified.

 

[winston1]

Also, if the OP were to somehow break the ring at that point, then it could create a condition where parts of the ring were overloaded as well.

Only if the junction was about one tenth the distance from the end of the ring.

 

[JohnW2]

What normally happens is people spur off spurs, effectively creating radial circuits. No one sticks to the rule of only a single socket (twin or single) on the spur. Therefore it is safer to use 4mm.

There's nothing 'normal' about that practice (which is contrary to regs, unless it's a fused spur), and it's ridiculous to suggest that no-one complies with that regulation. All electricians should - and most do. Even non-electricians, if they are aware of the regulation and/or are advised appropriately, probably usually comply with the regulation.

Also, if the OP were to somehow break the ring at that point, then it could create a condition where parts of the ring were overloaded as well. Hence, i thought you would have to get an electrical test on the circuit after the work was completed.

I think you need to explain that a bit more. Breaking into a ring will only increase the potential for some of the cable to be overloaded if it resulted in more sockets being near one end of the ring - but many (maybe most) rings already have a topology which makes that a theoretical possibility.

To put your comments about overloading 2.5mm² T+E into perspective, it is deemed to be able to carry about 39A (nearly 9kW) for at least an hour without coming to any harm, and I would suggest that it's incredibly unlikely, in a domestic environment, that people would plug 9kW worth of loads into one circuit and leave them all running for an hour!

Kind Regards, John

 

[ban-all-sheds]

Anyhow, there are so many rules these days, I just get a qualified electrician in to do the work and test.

Whatever your reasons for doing that, it's the right course of action.

 

[EFLImpudence]

If they use 2.5mm to spur from a ring, and connect a twin outlet at the end of the spur, then the cable won't be rated properly. It has a max of 24A, whereas a twin socket is rated at 26A.

I don't think anyone has pointed out that 2.5mm² T&E actually has a rating (method C) of 27A.

2.5mm is only rated at 32A when in a ring circuit.

No, it is still 27A but there are two of them so the circuit could support 54A at the centre.

They should use 4mm for a spur, or use a fused outlet.

A very good idea. Often suggested by me as you may find if you stumble elsewhere.

Also, if you break into a ring, then strictly speaking, I would expect that to be notifiable work, whereas I would expect the spur isn't notifiable, unless it is in a special location.

Your expectations are not the criteria. As said, it isn't.

I'm not part P qualified, but I think I know the basics.

 

[JohnW2]

I don't think anyone has pointed out that 2.5mm² T&E actually has a rating (method C) of 27A.

Not directly, but I did point out that 2.5mm² T+E is deemed able to carry about 39A (27A x 1.45) for at least an hour without coming to harm.

Kind Regards, John

 

[Risteard]

whereas a twin socket is rated at 26A.

No it isn't. A double socket outlet is rated for 20A.

 

[JohnW2]

No it isn't. A double socket outlet is rated for 20A.

As discussed many times before, MK (for one) sa y that their double sockets are rated at "13A per socket outlet" - and, despite lengthy discussions with them, I'm really none the wiser as to what it means.

One thing is clear, namely that it doesn't mean 20A. It presumably means either 13A or 26A. Whilst the latter is the subject of debate/argument, the former would probably be a bit silly!

Kind Regards, John

 

[Risteard]

As discussed many times before, MK (for one) sa y that their double sockets are rated at "13A per socket outlet" - and, despite lengthy discussions with them, I'm really none the wiser as to what it means.

One thing is clear, namely that it doesn't mean 20A. It presumably means either 13A or 26A. Whilst the latter is the subject of debate/argument, the former would probably be a bit silly!

Kind Regards, John

The BS1363 requirement is 20A. Therefore it cannot be stated that the rating of a socket outlet is otherwise.

 

[JohnW2]

The BS1363 requirement is 20A. Therefore it cannot be stated that the rating of a socket outlet is otherwise.

BS1363 requires the temperature of a double socket not to rise by more than a specified amount when carrying a total of 20A (strangely, 14A through one outlet and 6A through the other) for the specified period of time. A product does not fail to comply with BS1363 if its temperature rise is less than the maximum allowed and/or the manufacturer can show that it can safely carry more than 20A.

In other words, nothing is stopping a manufacturer producing a product which exceeds the requirements of BS1363 and specifying what the rating of their product is (which doesn't have to be the minimum required to conform with BS1363) - and it's far from impossible that MK have done just that.

Kind Regards, John

 

[EFLImpudence]

A more pertinent line of enquiry would be:

Why

The BS1363 requirement is 20A.

?