Use of 20AX switches in spurs off ring main

[GeorgeCooke]

if your electrician has an issue with the switches and the supply cable to the load not being protected why no incorporate a FCU module into the grid switch?

or find a different spark, one with more than a single brain cell.

Then you have 2 similar fuses in line, one in the fcu and one in the plug. Pointless.

 

[Darkwood]

@GeorgeCooke

When the manufacturers are 'clearly' wrong then as a professional you make an appropriate decision and if your ever in a situation where you are legally challenged then you can easily in your professional stance show their is an error in the manufacturers guidance, this is not about when the guidelines are clearly in error, this is about the BS7671 telling you to follow manufacturers guidance for which the majority of the time they are not in error thus you should be doing so.

 

[Midwest]

No because the outlet is the socket.you don't count a single switched socket as two.

So the switch don't count as an outlet

 

[richy3333]

Then you have 2 similar fuses in line, one in the fcu and one in the plug. Pointless.

Err, no?!

 

[GeorgeCooke]

Err, no?!

Of course it is pointless. With an overload quite likely both would blow and someone would often not realise and only replace one of them and be puzzled.

 

[littlespark]

So the switch don't count as an outlet

No it doesn’t. An outlet does as it says.... it’s where electricity comes OUT of the wall via a flexible cable to an appliance or equipment. Be that a socket and plug or an FCU

The clue’s in the name.

The only exception to the rule is a double socket.... two outlets being counted as one.

 

[redbarnman]

Thanks for the inputs so far. I don't have an issue with above counter switches - they are a convenience to isolate an appliance before pulling it out and then struggling in to remove the plug from the socket on the back wall. I also like to turn off some items if going away on holiday and this also makes it easy - rather than going to the CU and turning off the whole ring. My debate was more along the lines of 'why do switch suppliers sell a range of switches that can't be used for the function printed on them'. Putting a fused switch above the counter protects the 600mm of cable to the 13A socket, but the appliance plug top 13A fuse is what does the real protection. I reckon 600mm of cable is more reliable than the average white appliance. I will follow up on the reg 433.1.204 suggestion.

 

[littlespark]

Would the electrician be happy just making a joint behind a blank plate and creating a spur down to the socket?
Let him sign it off, then get another spark to replace blank with your DP switch.

Can I just check that this is a regular ring final circuit you are having installed in 2.5mm?

 

[GeorgeCooke]

Putting a fused switch above the counter protects the 600mm of cable to the 13A socket, but the appliance plug top 13A fuse is what does the real protection. I reckon 600mm of cable is more reliable than the average white appliance. I will follow up on the reg 433.1.204 suggestion.

No,wrong. The 13a fuse in the plug (not plug top which is a lid or cover and does not contain a fuse) is to protect the cable from the plug to the appliance, nothing else. Appliances should be internally protected as they are made for an international market connected by Schuko plugs where the only fusing is 16a MCB in the CU.

 

[Midwest]

No,wrong. The 13a fuse in the plug (not plug top which is a lid or cover and does not contain a fuse) is to protect the cable from the plug to the appliance, nothing else. Appliances should be internally protected as they are made for an international market connected by Schuko plugs where the only fusing is 16a MCB in the CU.

I call a plug a plug top, so there.

I thought specifically the design of a BS1363 plug 'top' and its associated BS1362, was to limit the overloading of the RFC. Initially only a 13A (brown) & 3A (red) BS1362 were introduced (all the others are marked black). The 3A fuse was for smaller ccc flexes to table lamps etc. Other flexes should be suitable for the max load of the appliance. Stand to be corrected.

 

[GeorgeCooke]

In that case I will correct you.
First it is a plug, not a plug top. Overloading of the ring final is taken care of by the 32 a MCB in the CU (prievously a 30a wire fuse).
Initially a range of fuses were introduced 1, 2, 3, 5, 7, 10, and 13a all in different colours. Can't remember all the colours but 3a was blue. As the fuse was only to protect the appliance flex it was later decided that only 3a and 13a were appropriate. At the same time 3a became red, 13a remained brown and all the other unofficial values became black.

 

[Toneyz]

Thanks for the inputs so far. I don't have an issue with above counter switches - they are a convenience to isolate an appliance before pulling it out and then struggling in to remove the plug from the socket on the back wall. I also like to turn off some items if going away on holiday and this also makes it easy - rather than going to the CU and turning off the whole ring. My debate was more along the lines of 'why do switch suppliers sell a range of switches that can't be used for the function printed on them'. Putting a fused switch above the counter protects the 600mm of cable to the 13A socket, but the appliance plug top 13A fuse is what does the real protection. I reckon 600mm of cable is more reliable than the average white appliance. I will follow up on the reg 433.1.204 suggestion.

We used to have a bank of grid switches and a single unswitched socket in an adjacent cupboard, however, this needs to still be accessible. You can also have an individual D.P. switch engraved if required. Never had a problem with a fuse blowing more the case of the RCD tripping.

 

[Midwest]

In that case I will correct you.
First it is a plug, not a plug top. Overloading of the ring final is taken care of by the 32 a MCB in the CU (prievously a 30a wire fuse).
Initially a range of fuses were introduced 1, 2, 3, 5, 7, 10, and 13a all in different colours. Can't remember all the colours but 3a was blue. As the fuse was only to protect the appliance flex it was later decided that only 3a and 13a were appropriate. At the same time 3a became red, 13a remained brown and all the other unofficial values became black.

If you look at the history of socket outlets, you will read there were also referred to as ‘plugs’, certainly my elders did, and as the term ‘plugs’ was used to call a socket, myself and others referred to plugs as ‘plug tops’, to differentiate between the two. If you get my drift.

I take your point about overload protection, but I was referring to the whole design of an RFC, and fusing was used to limit the scope of appliances, from the previous 15A max.

Still stand by my point, the original 1362 fuses were 3 & 13A (although I see 7A mentioned).

 

[Ian1981]

If a single appliance is used in the socket fed from a 20amp grid switch then what overload protection is required and actually needed?
A single appliance with a plug top will not overload anything provided that the cable feeding the socket is selected accordingly

 

[Silly Sausage]

I use 20A BS1362 fuses, saves fuse swapping time ...
20A Fuse for 13A Plug - BS1362 - https://www.pat-testing-training.net/articles/20a-mains-plug-fuse.php