Four cables into one single socket

[Simlec]

Some socket outlets state on the back max 4x2.5mm (yes not all, but some)
The pic on the left is perfectly acceptable. How would you feel about the pic on the right with a 4mm to the first spured socket & 2.5mm to the next one?

 

[Pete999]

Some socket outlets state on the back max 4x2.5mm (yes not all, but some)
The pic on the left is perfectly acceptable. How would you feel about the pic on the right with a 4mm to the first spured socket & 2.5mm to the next one?

Lads show me where it states that Richards left hand scenario is acceptable and conforms to 7671

 

[Richard Burns]

So your saying that providing you take two spurs from the same socket it's OK? Sorry disagree with you on that one

No problem, you are entirely entitled to disagree, and from a practical point of view I would not want to do it.

Some socket outlets state on the back max 4x2.5mm (yes not all, but some)
The pic on the left is perfectly acceptable. How would you feel about the pic on the right with a 4mm to the first spured socket & 2.5mm to the next one?

BS7671 does not give you the option of spurring from a spur without fusing down, however you could design it that way as a departure from BS7671, but again you would risk overloading the ring at the take off point and would be able to pull over the current carrying capacity of the 4mm from two double sockets, so would have to take diversity into account for the socket outlets which is hard to do (though obviously applied for general socket circuits in a very large way).

Far better to design circuits without messing about with calculations and pushing the limits, or am I just lazy?

 

[Simlec]

Lads show me where it states that Richards left hand scenario is acceptable and conforms to 7671

Should it be you showing us where it says it's the work of the devil .
Distrubted socket outlets are a way of conveniently plugging in temporary equipment, if it's likely to be over loaded then a dedicated circuit would be the way forward.

 

[Richard Burns]

Lads show me where it states that Richards left hand scenario is acceptable and conforms to 7671

This is not specifically prohibited by BS7671 therefore it is permitted.
433.1.5 gives overload requirements for rings and does not require that only one spur may be taken from a point on the ring.
The requirement not to overload the cables may prevent you from designing a ring with two unfused spurs off the first socket in the ring and designed to run fan heaters from those sockets as this could overload the short leg of the ring.

 

[Silly Sausage]

Lads show me where it states that Richards left hand scenario is acceptable and conforms to 7671

OK Pete, look at the 32A Radial in Appendix 15.
The top branch has two sockets, in series, taken off a socket.
That is no different to two separate sockets, in parallel, taken off a socket.
The potential load on the supplying outlet is the same in both cases.

That diagram also implies BS1363 socket outlets are rated at, at least 32A

 

[Pete999]

I 'll just stick to my guns and say I disagree with you and leave it at that, no hard feelings

 

[Itisonlyme]

I'd be amazed if the whole circuit conformed to any standard. Especially the light supply fed around the switch by splitting the outer insulation, and the way the cable had been fed into the backbox was a joke.

Seems there is a difference of opinion as to whether two spurs in parallel is acceptable and two in series also. But as I had two in parallel and one in series plus a light spur off the same ring point I'm hoping we can agree it was a proper lash up!

Thanks very much for all the comments

 

[Pete999]

I'd be amazed if the whole circuit conformed to any standard. Especially the light supply fed around the switch by splitting the outer insulation, and the way the cable had been fed into the backbox was a joke.

Seems there is a difference of opinion as to whether two spurs in parallel is acceptable and two in series also. But as I had two in parallel and one in series plus a light spur off the same ring point I'm hoping we can agree it was a proper lash up!

Thanks very much for all the comments

I'll go along with that mate no worries

 

[richy3333]

I see this alot. Its always the single gang socket on the landing that gets the kicking.

I bet one of the spurs feeds a security light, and the other is for a trouser press in the wardrobe that backs onto the single socket :laugh:

Well you can tell the spark that only does posh houses, security lights, trouser presses. What next a teasmaid!

 

[Rockingit]

Is it not just easier all round here to remember that BS7671 is not actually a design guide? When considered the other way around as being guidance on what you CAN'T do, the rest of life becomes much easier as its then up to the designer to justify their decisions. And we know the BGB is littered with contradictions, so why should this be any different?

Personally, I'd be looking to change that arrangement, not because of some reg on spurs which may or may not exist, but simply as I'd be concerned about the mechanics of four conductors jammed into a single small terminal and not actually being that secure.....and there ARE regs for that one!!

 

[Itisonlyme]

Personally, I'd be looking to change that arrangement, not because of some reg on spurs which may or may not exist, but simply as I'd be concerned about the mechanics of four conductors jammed into a single small terminal and not actually being that secure.....and there ARE regs for that one!!

Amen to that.

 

[Deleted member 9648]

[QUOTE

Personally, I'd be looking to change that arrangement, not because of some reg on spurs which may or may not exist, but simply as I'd be concerned about the mechanics of four conductors jammed into a single small terminal and not actually being that secure.....and there ARE regs for that one!![/QUOTE]

Blame the installer not the terminal,an experienced electrician will know if a connection is secure or not without resorting to regulations. If you endorse that point of view then there should be a regulation against 10mm cables in shower pullswitches.

 

[Rockingit]

[QUOTE

If you endorse that point of view then there should be a regulation against 10mm cables in shower pullswitches.

Although the difference with that example is that I would expect a shower isolator rated above 32 amps to have terminals sized to accept a 10mm cable.

I'm not in the slightest trying to remove the skill/experience of the installer at being able to jam in 4 x 2.5's and make them stay - let's face it we've all done it I'm sure - my point is that if we're going to have an argument about regs and 'best practice' then the designer (repairer!) is placed in mind to improve the situation, not just continue it.

 

[Itisonlyme]

[QUOTE

Personally, I'd be looking to change that arrangement, not because of some reg on spurs which may or may not exist, but simply as I'd be concerned about the mechanics of four conductors jammed into a single small terminal and not actually being that secure.....and there ARE regs for that one!!

Blame the installer not the terminal,an experienced electrician will know if a connection is secure or not without resorting to regulations. If you endorse that point of view then there should be a regulation against 10mm cables in shower pullswitches.[/QUOTE]

I would say the 4 wires into the old socket did indeed feel secure at the terminal, this is the only good thing I could say about the work done. He/she was adept at tightening screws.

 

[Itisonlyme]

Thought I'd check the MK website as I really don't see 4 * 2.5mm going into one of these terminals, they quote max 3 in the spec

 

[telectrix]

it's not just the terminals, it's the conductors squashed in the backbox that's also a major concern.

 

[Silly Sausage]

it's not just the terminals, it's the conductors squashed in the backbox that's also a major concern.

Get the Hilti out and dig a bigger backbox in.
Typical lazy scouser.

 

[telectrix]

hilti?? now that's lazy. a scouser uses the proper tools. hammer and chisel. because we're 'ARD.

 

[Silly Sausage]

hilti?? now that's lazy. a scouser uses the proper tools. hammer and chisel. because we're 'ARD.

Probably because you've nicked each others tools power tools and flogged them on ebay. :smilielol5::smilielol5::smilielol5: