DIY replacement of electrics in kitchen, sanity check & questions

[TonyBelfast]

Does he know anything about UK regs? It is different down under. They use funny plugs looking like a crows foot and rated at only 10 amps. They certainly don't wire them on 4mm cable.

There are no regs - this is Belfast, part P does not apply. I called building control, asking if I could do the work, had to have notify / have the work inspected, if I needed to employ an electrician because it's the kitchen etc. they said there are currently no regulations covering installation of electrics in domestic dwellings - and I can do what I want. That said, he has worked in the NI, and I'm sure he'll know how to test the resistance of the circuit etc. right. I could always buy one of these.

 

[ban-all-sheds]

Surely that is through the socket via two plugs.

Not only that.

The total load on the supply cable is also specified - for a single socket it has to have an additional 6A flowing.

(A later amendment changed the multiple (fused) loading to 20A evenly distributed)

Please see Appendix 15B.

I have.

It is in error.

 

[ban-all-sheds]

That's not the same as passing through.

It is, except to those who are so pathetic and immature that they want to pretend otherwise.

I have read it and taught you most of what you know about it. The only mention of current is a 20A heat test with the 20A conected via the load side.

Precisely.

How sockets perform with a load on the supply cable >20A is undefined.

Perfect in all areas.

But my main attribute is honesty.

I'm not questioning your honesty.

I am sure that with your lack of ability to properly comprehend what you read, you do actually believe the nonsense you write.

 

[TonyBelfast]

How sockets perform with a load on the supply cable >20A is undefined..

Are you trying to say that domestic sockets are not suited for use on a (standard) 32A radial, ever? I find it hard to believe this would be unsafe, but what would you have me do here?

 

[EFLImpudence]

The total load on the supply cable is also specified - for a single socket it has to have an additional 6A flowing.

Why?

(A later amendment changed the multiple (fused) loading to 20A evenly distributed)

What does that mean when there is a 20A loading at the socket?

I have.
It is in error.

Ok.



What are we to make of today's revelation?
What about 433.1.204?

Are we to wire all sockets on a short spur form the main circuit - ring and/or radial - cable?

 

[echoes]

... a short spur form the main circuit - ring and/or radial

Perhaps these spurs could be wholly enclosed in a back box, or even better, wholly enclosed in a terminal.

 

[EFLImpudence]

That's what I meant - if needed.

 

[ban-all-sheds]

Why?

To replicate the design point of a ring final, which is no sustained current in any part of the circuit > 20A?

What does that mean when there is a 20A loading at the socket?

Not 14A + 6A any more.

What are we to make of today's revelation?
What about 433.1.204?

How {is that affected|does that affect this}?

Are we to wire all sockets on a short spur form the main circuit - ring and/or radial - cable?

Not on a 32A ring, but I would give serious consideration to doing that on a 32A radial, for the simple reason that you cannot buy a BS 1363 socket which has had to demonstrate any capabilities wrt circuit cable currents > 20A.

 

[EFLImpudence]

To replicate the design point of a ring final, which is no sustained current in any part of the circuit > 20A?

Yet the requirement is for conductors of a ring to have a minimum ccc of 20A, with the stipulation that those with a ccc of 27A is the minimum that may actually be used.

Not 14A + 6A any more.

What is it now?

How {is that affected|does that affect this}?

As above - plus a 32A opd is stipulated.

Not on a 32A ring, but I would give serious consideration to doing that on a 32A radial, for the simple reason that you cannot buy a BS 1363 socket which has had to demonstrate any capabilities wrt circuit cable currents > 20A.

What has brought about this epiphany over such long practiced methods?

 

[ban-all-sheds]

Yet the requirement is for conductors of a ring to have a minimum ccc of 20A, with the stipulation that those with a ccc of 27A is the minimum that may actually be used.

Not so - the stipulation is for a minimum Iz of 20A, not 27A.

What is it now?

20A evenly distributed.

As above - plus a 32A opd is stipulated.

Yes, but that's for a ring, not a radial.

What has brought about this epiphany over such long practiced methods?

Realising that BS 1363 conformance does not guarantee that a socket will not overheat when the load on the supply cable exceeds 20A.

 

[ban-all-sheds]

Are you trying to say that domestic sockets are not suited for use on a (standard) 32A radial, ever? I find it hard to believe this would be unsafe, but what would you have me do here?

Run the cable for the 32A radial, and take short drops to each socket.

 

[EFLImpudence]

Not so - the stipulation is for a minimum Iz of 20A, not 27A.

Yes, but 2.5mm² is the minimum csa allowed which has a ccc of 27A.

20A evenly distributed.

You mean 20A evenly distibuted at the socket (2 x 10A) and the load evenly distributed in the supply cable?

Yes, but that's for a ring, not a radial.

Yes, but the socket conditions are the same -
and evenly distributed in the supply cable obviously refers to a ring.

Realising that BS 1363 conformance does not guarantee that a socket will not overheat when the load on the supply cable exceeds 20A.

Fair enough.

 

[ban-all-sheds]

Yes, but 2.5mm² is the minimum csa allowed which has a ccc of 27A.

Not for all installation methods.

Where does 433.1.204 stipulate a minimum Iz of 27A?

You mean 20A evenly distibuted at the socket (2 x 10A) and the load evenly distributed in the supply cable?

I take it to mean 20A evenly distributed between the outlets.

"Evenly distributed in the supply cable" makes no sense, as the supply cable carries 20A.

Yes, but the socket conditions are the same

Indeed they are. No more than 20A on the cable supplying the socket.

and evenly distributed in the supply cable obviously refers to a ring.

No, it refers to the cable supplying the socket in the tests required by BS 1363.

 

[EFLImpudence]

Not for all installation methods.

No, but some - two, but probably only one applies.

Where does 433.1.204 stipulate a minimum Iz of 27A?

It doesn't but it stipulates a minimum csa of 2.5mm² which has an Iz of 27A method C.

 

[JohnW2]

Run the cable for the 32A radial, and take short drops to each socket.

Is this proposal not rather silly?

Whatever tests BS1363 may or may not require, I seriously doubt that any significant number of people (if any) have ever done as you suggest for the reason you are mentioning, and I am not aware of any reports of a problem with the 'standard practice'.

Whatever tests BS1363 may or may not require, I seriously doubt that there is any issue relating to a current of 32A (or probably more) passing between two conductors that happen to be joined in the terminal of a BS1363 socket. Those terminals are generally no 'inferior' to those of a 30/32A JB, and if the connection is made securely virtually no heat will be generated at the joint, so there will be virtually no thermal implications for the socket.

To do as you suggest and introduce countless additional ('unnecessary') joints into a radial circuit, as compared with the way in which virtually everyone has always wired such a circuit would seem to me to be undesirable.

Kind Regards, John