4mm to 2.5mm on radial

[AndyPRK]

Inspect some sockets to see if they are the same thickness wire than the wire at the fuse.

Guess it is a radial !

 

[JohnW2]

...
32A - most sockets downstairs and upstairs
32A - again doesnt seem to turn anything off
32A - cooker, an adjacent double socket, a single socket in bedroom above, a fused switch for outside socket and dishwasher (which presumable is plugged into another socket beneath the kitchen units)

Those three 32A ones only have single (red) conductors connected to them, so none can be rings, per se (i.e. are almost certainly all radials).

I suppose that the one other (very unlikely, and very wrong) possibility one should rule out is that two ends of a single socket ring have been connected to different MCBs (left and middle ones). It sounds as if you have probably ruled that out since, if so, the left-hand MCB would not switch off most of your sockets unless the middle MCB was also off - but, for completeness, can you confirm that the left-hand 32A MCB does switch off most of the sockets even if the middle MCB is 'on'?

Kind Regards, John

 

[Richely]

Yes, thats correct, if the left fuse is of but middle one is on then most sockets are of...i also looked behind 6 sockets both upstairs and downstairs (from both 32A fuses) and all are in 2.5mm cable...there are more sockets but not so easy to get to but can check these later...so seems like most of house is in 2.5mm

 

[AndyPRK]

1970s wiring.

That looks thicker than 2.5mm to me.
Well the one with 2 cables.


The other one looks later and could be 2.5

Can you see a difference in person?

 

[Richely]

Not sure if these help more, they are different sockets...but looks same as 2.5mm a far as i can tell..i will try and get a better idea when check other sockets

 

[chivers67]

Can you wipe off the dust of the external insulation in those last three shots?

 

[Richely]

I tried to get better pics...and also compared to some 2.5mm i had and i think is same...unfortunately i dont have any 4mm but i guess it would be obviously bigger?

 

[flameport]

Almost certainly 2.5mm² - the 1970s stuff is likely to be stranded core rather than solid, which will make it appear slightly larger.
4mm² would be noticeably larger, and would be a very unusual size to find in a domestic dwelling particularly from the era of rewireable fuses.

 

[Richely]

I think the 4mm from the MCB must go to a socket i havent yet checked and then pretty much the rest have been added using 2.5mm.
So does this mean i should replace the 32A fuses with 20A to be safe?

 

[sparkydave in wales]

It sounds like the ring circuits start at the junction boxes, maybe the fuse box was moved at some point? I would suggest getting someone in to test it properly as any advice given here could be based on guesswork, but if you get a decent electrician and explain what you have found, they will be able to give you the information you need

 

[JohnW2]

It sounds like the ring circuits start at the junction boxes...

Nothing's impossible [i.e. that there could be 'lollipop' circuit(s)] - but, unless I've missed something, I don't think we've yet been told/shown anything which actually demonstrates that there are any ring (or lollipop) circuits at all, have we?

Kind Regards, John

 

[sparkydave in wales]

Nothing's impossible [i.e. that there could be 'lollipop' circuit(s)] - but, unless I've missed something, I don't think we've yet been told/shown anything which actually demonstrates that there are any ring (or lollipop) circuits at all, have we?

Kind Regards, John

Which is why I suggested it needs testing properly

 

[JohnW2]

Which is why I suggested it needs testing properly

Yes, and I obviously agree with that bit of what you wrote.

As you will realise, it was the first part of what you wrote that I was wondering about - I was wondering why you said that "it sounds like the ring circuits start at the junction boxes" when we don't really even have any evidence that there are any ring circuits. As you said yourself in the same post, any advice based on guesswork is useless.

Kind Regards, John

 

[Richely]

Thanks all for your help with this, i will get an electrician in to give it the once over and let you know.

 

[securespark]

It could be that there is a 4 milli feed leaving the CU, then it splits into a 2.5 ring final.