Interesting Conundrum 1.5 power

[Dustydazzler]

So...

A mate just moved into his new house and wants a few extra sockets added for wall mounted TVs etc
No problem you would think as house it fairly modern, I would say less than 10 years old...
Popped round on my way home this evening and looked at the consumer unit , looked okay dual rcd split board so rcd present and correct.
Here comes the kicker , I noticed all the circuits labelled sockets were on 16a MCBs , no rings at all.. So one would assume all socket were wired in 2.5 radials... NOPE. Dropped 2 double socket fronts down and all the power is run in 1.5.

My initially thinking is to extend the circuits in 2.5 but then I got thinking while driving home would anyone think it was badger rough to extend the circuit in 1.5 keeping the cable size the same through-out

Thoughts please

 

[littlespark]

Is 16A suitable OCPD for 1.5mm which is no doubt run in insulation part of its route...

Is this ALL power? including kitchen appliances?

 

[Dustydazzler]

Is 16A suitable OCPD for 1.5mm which is no doubt run in insulation part of its route...

Is this ALL power? including kitchen appliances?

I dropped the cover of the board and everything back at the board is 1.5 orn16amp mcbs for socket circuits ( 3 circuits total for sockets) , dropped a double off in the kitchen was 1.5 and double off in the lounge and it was 1.5

I can honestly say its been a good while since I have seen a new build with 1.5 used to wire all the sockets

 

[pc1966]

That is astonishingly cheap and disappointing.

It might be OK for most light electronics use, but hardly good for a kitchen of high power stuff or even form some vacuum cleaners, etc, with a big switch-on surge. It also more or less guarantees that a blown fuse will always take out the MCB as well, so rubbish selectivity.

 

[Dustydazzler]

That is astonishingly cheap and disappointing.

It might be OK for most light electronics use, but hardly good for a kitchen of high power stuff or even form some vacuum cleaners, etc, with a big switch-on surge. It also more or less guarantees that a blown fuse will always take out the MCB as well, so rubbish selectivity.

I remember when these houses were thrown up and everything went to the cheapest bidder, the cheapest of everything was used and it shows in the finish. all the cables are plastered in , no capping used , everything is wonky as ----.
My mate just paid top top money for the house so there is no way I can tell him to re-wire all the sockets , he has already had some plumbing and drainage issues he has had to fork out nearly a grand to fix.

 

[swaRRR]

1.5mm and 16a for sockets is fine. Yes, even in kitchens. Lots of countries on the continent do this but with the caveat that there is usually a socket limit per radial.

 

[pc1966]

1.5mm and 16a for sockets is fine. Yes, even in kitchens. Lots of countries on the continent do this but with the caveat that there is usually a socket limit per radial.

They also have lots of circuits to make up for it, and usually kitchen appliances are on dedicated radials.

But as they don't have fused plugs like we do, they have to balance MCB rating against appliance cable adiabatic limit which is why 0.5mm flex is not seen.

 

[Dustydazzler]

I am going to extend the socket circuits in 1.5 and keep the same size cable through-out , just seems a bit strange wiring sockets in 1.5 but with the price of cable these days maybe 1.5 socket radials will become all the fashion like on the continent

 

[pc1966]

I am going to extend the socket circuits in 1.5 and keep the same size cable through-out , just seems a bit strange wiring sockets in 1.5 but with the price of cable these days maybe 1.5 socket radials will become all the fashion like on the continent

Well for the same capacity you need twice as many circuits (more really, due to poorer diversity) so comparing 2*N 16A radials on 1.5mm versus N 32A RFCs on 2.5mm I doubt it is cheaper.

Of course if no one can afford to use the power, then telling them it is basically an indoor camping supply might work!

 

[mattg4321]

What are the chances it was wired by foreign sparks?

 

[Dustydazzler]

What are the chances it was wired by foreign sparks?

Highly likely as there is some writing on the cables in the consumer unit and it ain't English

 

[timhoward]

This really beggars belief. I'd be livid if it were my house.

1.5mm and 16a for sockets is fine. Yes, even in kitchens. Lots of countries on the continent do this but with the caveat that there is usually a socket limit per radial.

It can meet the regs but it depends how the cable is run. Unclipped in an insulated wall or in loft under insulation and there's an issue.

My mate just paid top top money for the house so there is no way I can tell him to re-wire all the sockets

I honestly think this is worth a complaint. NHBC Section 8.1.7 says that the electrical installation should comply with BS7671.

If they've skimped and used 1.5sq mm I'd bet there are cables loose in insulation somewhere. It's also worth a shot saying they they haven't used standard circuits as per appendix 15 (I know they are not obliged to!).

 

[littlespark]

The only way 1.5mm c.c.c is above 16A is if its clipped direct in open air. Bury it in a wall, or run it through insulation and youre down to 14 approx.

I would be wary if i found a house wired like this.

1.5 off a 13A fused spur... but not from 16A breaker

You certain it is 1.5, and not some weird inbetweeny size


If you dont say anything... and theres a fire down to melted cables... youll kick yourself.
Mention it to him. Tell him its not how you would have done it. Leave the responsibility up to him to have it changed if he wants to.
If he values your opinion, he might do something. (dropping 16A to 10 might be a start)

 

[Dustydazzler]

The only way 1.5mm c.c.c is above 16A is if its clipped direct in open air. Bury it in a wall, or run it through insulation and youre down to 14 approx.

I would be wary if i found a house wired like this.

1.5 off a 13A fused spur... but not from 16A breaker

You certain it is 1.5, and not some weird inbetweeny size


If you dont say anything... and theres a fire down to melted cables... youll kick yourself.
Mention it to him. Tell him its not how you would have done it. Leave the responsibility up to him to have it changed if he wants to.
If he values your opinion, he might do something. (dropping 16A to 10 might be a start)

Defiantly 1.5 cable , and all on 16amp circuits. Feels very much European

I didn't have time to add up all the sockets but I would suspect that there is around 6 or 7 sockets on each 16amp radial , possibly 1 circuit for upstairs , 1 for downstairs and 1 for the kitchen , but this would require further investigation

Certainly not how I would have wired a brand new house but an interesting way to wire a house never the less

Trying to convince him to rewire all the circuits in a finished house less than 10 years old is going to be a tough conversation , there is no way he will want all the walls chased out

 

[littlespark]

At 10 years old, you would think the builder is still trading.

All you can do is give the owner your opinion. You dont have to convince him.... if he knows the likelyhood of danger, he'll make his own decision.
It could be perfectly ok, if they never overload the cable... and there will be some safety margin built into the c.c.c.

What code would you give, if it were to have an EICR? C2 or C3? Potentially dangerous or improvement recommended

 

[Dustydazzler]

At 10 years old, you would think the builder is still trading.

All you can do is give the owner your opinion. You dont have to convince him.... if he knows the likelyhood of danger, he'll make his own decision.
It could be perfectly ok, if they never overload the cable... and there will be some safety margin built into the c.c.c.

What code would you give, if it were to have an EICR? C2 or C3? Potentially dangerous or improvement recommended

Certainly not a C2 and there is no real danger risk as the 16amp Mcb would trip before the cables became loaded

C3 as 16amps is a bit restrictive and could cause nuisance tripping if you turn several things on at the same time

If the 16amp circuit only fed a couple designated sockets for say a small room or study office then I probably wouldn't bother coding it at all

 

[littlespark]

I take it everything else is ok? RCD protecting etc?

Its very unlikely that they will be pulling exactly 15A for long durations... enough to melt the cable and burn something before the conductors touched as a fault, but not trip the OCPD as an overload

It just doesn't seem to sit right.

 

[UNG]

1.5mm and 16a for sockets is fine. Yes, even in kitchens.

Based on what

Lots of countries on the continent do this but with the caveat that there is usually a socket limit per radial.

A lot of the continental countries electrical systems are a law unto themselves I dread to think how many C2's you would find if they were inspected to BS7671

 

[timhoward]

Certainly not a C2 and there is no real danger risk as the 16amp Mcb would trip before the cables became loaded

If I could see for sure that the cable route / installation method reduced the CCC to under 16A then I'd feel I had to C2 it.
As unlikely as it is to actually cause a problem I wouldn't want to state things are satisfactory if it's not right.
The design of T+E requires some talented misdirected DIY to cause a L-N fault but nothing is fool-proof for a sufficiently talented fool!

Its very unlikely that they will be pulling exactly 15A for long durations

It could in fact pull 32 amps for approx 10 seconds without tripping. It would take rather a lot of arranging though!

I think I might pass on this job, there's easier money to be made with less thinking!

 

[Dustydazzler]

If I could see for sure that the cable route / installation method reduced the CCC to under 16A then I'd feel I had to C2 it.
As unlikely as it is to actually cause a problem I wouldn't want to state things are satisfactory if it's not right.
The design of T+E requires some talented misdirected DIY to cause a L-N fault but nothing is fool-proof for a sufficiently talented fool!

It could in fact pull 32 amps for approx 10 seconds without tripping. It would take rather a lot of arranging though!

I think I might pass on this job, there's easier money to be made with less thinking!

That is the frustrating thing , this on the face of it should be a piece of cake job to add 2 or 3 new sockets to a new build with dot and dab walls just chop in some flush boxes spur off a nearby socket etc. A lovely days work.
Now I am faced with non conventional circuits in a house less than 10 years old, and to think this is a small estate of around 18-20 houses and if the same sparks wired them all then they will all be like this.
Very annoying