Adding two spur sockets to Ring Final

[EFLImpudence]

OR - it shows that the 32A circuits (and all the palaver about ring circuits) are not really necessary.

 

[JohnW2]

OR - it shows that the 32A circuits (and all the palaver about ring circuits) are not really necessary.

Indeed - as I implied, that may well be true of real-world domestic installations.

However, I could suggest that it would be incredibly unlikely that any significant 'problem' would arise (in a real-world domestic installation) if one had multi-socket radials wired in 2.5mm² cable protected by a 32A device - and very probably even if it were a 40A or 50A device .... but there is obviously a limit to how far one can/should go in 'ignoring' situations which are 'possible, even if incredibly improbable!

Kind Regards, John

 

[SUNRAY]

OR - it shows that the 32A circuits (and all the palaver about ring circuits) are not really necessary.

but the alternative can be very expensive and a waste of our worlds deposits.

 

[JohnW2]

but the alternative can be very expensive and a waste of our worlds deposits.

What 'alternatives' (to 32A circuits) were you considering?

Kind Regards, John

 

[securespark]

Some of us only have 16A radials and 16A outlets.

Pah, Portuguese rubbish...

 

[SUNRAY]

What 'alternatives' (to 32A circuits) were you considering?

Kind Regards, John

Multiple 16A radials?

 

[JohnW2]

but the alternative can be very expensive and a waste of our worlds deposits.

What 'alternatives' (to 32A circuits) were you considering?

Multiple 16A radials?

Well, it only takes two 16A radials to replace one 32A circuit and (assuming Method C) one could presumably use 1.5mm² cable (or, in fact 1.0mm² cable if the regs allowed that for 'power circuits'), rather than the 2.5mm² cable (again, assuming Method C) required for a 32A ring or the 4mm² (yet again assuming Method C) required for a 32A radial - and, not only can the cable be smaller, but the total length of cable needed for the two radial should not really be any greater than one would need for one ring (since one could simply install it using exactly the same route one would use for a ring, but with a bit of cable missing in the middle, actually save a bit of cable).

Hence, given that the two 16A radials would use a slightly shorter (possibly even 'appreciably shorter') total length of a smaller CSA cable than would be needed for one 32A ring (i.e. less copper), I'm not sure in what sense the two 16A radials (the 'alternative' to a 32A circuit) would "be very expensive and a waste of our worlds deposits". I suppose that must be missing something!

However, for reasons I've explained, I am personally even less keen on the idea of 16A radials than I am of 20A ones, since just a couple of credible loads could easily 'overload' it.

Kind Regards, John

 

[plugwash]

However, for reasons I've explained, I am personally even less keen on the idea of 16A radials than I am of 20A ones, since just a couple of credible loads could easily 'overload' it.

And to prevent that from happening you need to install more circuits.

So rather than your 32A kitchen ring being replaced with two 16A or 20A radials, you end up replacing it with four or so, one for the washing machine, one for the dishwasher, one for the tumble drier and one for the rest.

 

[ebee]

Some folk seem averse to ring final circuits.
A UK thing really.
Has advantages (and disadvantages) So do radials.
Those of us a certain age were brought up on ring finals, some even believe you are not a proper electrician unless you install rings.
Others avoid rings at all costs.
There are pros, there are cons with either rings or radials.
Both exist and can be utilised

 

[winston1]

Perhaps there should be a limit to the number of sockets per radial. In France I understand each radial is limited to 8 sockets.

 

[Taylortwocities]

Perhaps there should be a limit to the number of sockets per radial. In France I understand each radial is limited to 8 sockets.

There isn’t a limit. It’s up to the person designing the circuit.
And, we don’t live in France.

 

[SUNRAY]

And to prevent that from happening you need to install more circuits.

So rather than your 32A kitchen ring being replaced with two 16A or 20A radials, you end up replacing it with four or so, one for the washing machine, one for the dishwasher, one for the tumble drier and one for the rest.

Precisely...
I would suggest 2 for the rest to reduce the potential for tripping the circuit with the fridge, don't forget the kettle and toaster will be right on the limit of 16A. Fridge, microwave, iron and Henry is up at 16A too. OK I'm looking at extremes of potential loads but seeing the way Mrs Sunray operates, which I suspect is not too far away from other domestic godesses, I strongly believe it needs to be taken into consideration.
Let's face it, most new builds have 2x 32A rings for the kitchen 6x 13A radials and one 32A ring for the kitchen it just happens to be 2x 32A OCPD in the CU and we add a secondary CU (in the form of a switch plate) to save cable.

 

[SUNRAY]

Well, it only takes two 16A radials to replace one 32A circuit and (assuming Method C) one could presumably use 1.5mm² cable (or, in fact 1.0mm² cable if the regs allowed that for 'power circuits'), rather than the 2.5mm² cable (again, assuming Method C) required for a 32A ring or the 4mm² (yet again assuming Method C) required for a 32A radial - and, not only can the cable be smaller, but the total length of cable needed for the two radial should not really be any greater than one would need for one ring (since one could simply install it using exactly the same route one would use for a ring, but with a bit of cable missing in the middle, actually save a bit of cable).

Hence, given that the two 16A radials would use a slightly shorter (possibly even 'appreciably shorter') total length of a smaller CSA cable than would be needed for one 32A ring (i.e. less copper), I'm not sure in what sense the two 16A radials (the 'alternative' to a 32A circuit) would "be very expensive and a waste of our worlds deposits". I suppose that must be missing something!

However, for reasons I've explained, I am personally even less keen on the idea of 16A radials than I am of 20A ones, since just a couple of credible loads could easily 'overload' it.

Kind Regards, John

I think you've just negated your point of view.
However as in posts #83 & #87 and your #82 (quoted) straightaway there is a requirement for more than 2 radials to replace one ring.

The last thing I want to see is the massive CU's our foreign cousins have to find a home for.

 

[securespark]

I grew up on ring finals.

In fact, when I first started working as an apprentice, sparks were still installing to the 14th. One guy I worked with used to fit a ring final downstairs and spur off each socket to another one in the corresponding room upstairs.

But 30 years of fault finding horrendous f**k ups on ring finals has put me off them big time!

And the testing procedure for radials is much more straight forward.

I am OK with 20A radials, especially for a "bedroom" floor circuit. Obviously, you need to do your design work, but most properties up to 3/4 beds would be fine with a single 20A radial for such a floor. The IET has written at least one article discussing such design.

I wouldn't install a 16A multi-socket circuit though.

 

[SUNRAY]

I grew up on ring finals.

In fact, when I first started working as an apprentice, sparks were still installing to the 14th. One guy I worked with used to fit a ring final downstairs and spur off each socket to another one in the corresponding room upstairs.

But 30 years of fault finding horrendous f**k ups on ring finals has put me off them big time!

And the testing procedure for radials is much more straight forward.

I am OK with 20A radials, especially for a "bedroom" floor circuit. Obviously, you need to do your design work, but most properties up to 3/4 beds would be fine with a single 20A radial for such a floor. The IET has written at least one article discussing such design.

I don't think I've particuarly found faultfinding on rings any more difficult or common than radials.
I agree the bedrooms don't usually require a 32A circuit, in fact I have a single ring for my home (plus another for kitchen) and the peak current over a several year period was only mid 20's. (>50A for kitchen ring)