kitchen wiring

[bongos]

Some say as a RFC is rated to 32A so you can't use 20A rated switches.

Some say that 20A switches are OK as they will not actually be switching more than their rated load.

A bit of ambiguity. I guess it's open to interpretation of the regs.

They are not specifically listed in BS7671 as an acceptable device to be connected directly to a RFC

Arghhhhhhhh... Just when I had made my mind up one way...
I always like a bit of clarification with these things and at the moment I am getting a bit of work experience with two different sparks, both of whom interpret the regs differently!

 

[Spark123]

Personally I don't see the issue with the 20A DP switches as they are just in effect acting like a JB feeding an unfused spur, the terminals in the MK ones for instance are the same as those in a fused spur version so they are rated no less on the supply side. However the letter of the regs doesn't say they are allowed in RFCs - daft if you ask me.

 

[ban-all-sheds]

Is this ever a problem in relation to discrimination, to have a 13A fuse in the FCU and a 13A fuse in the appliance plug?

If it is it's easily solved by using unfused plugs.

If the appliance uses a fuse lower than 13A, often the lower rated fuse is put in the fcu and a 13A fuse put in the plug top. This helps when having to change a fuse, although you need to mark the plugtop to ensure that if the appliance is moved, the correct fuse is fitted.

Or use unfused plugs.

What I meant was that there could be two 13A fuses inline with each other.

Not if you use unfused plugs.

 

[sparkyspike]

My comment on not using 20A DPs on a ring was concerning this installation in particular. I would avoid using an unfused spur in a kitchen, where high loads, such as kettles, cookers and washing machines, can be plugged in. I would also use a 20A DP only on a radial. Just my preference.

 

[skenk]

Cant really see the difference between the fuse in the plug-top of an appliance plugged into a single socket and the fuse in a FCU feeding the same appliance . . .

For me the debate between the 2 options of FCU above/outlet plate below or 20A switch above/single socket below comes down to a debate between the inconvenience of having to change the fuse (inconvenient if single socket below) or the inconvenience of disconnecting for future testing (flex outlet)

The idea of having FCU above and single socket below with 13A fuse in the plugtop and smaller fuse above seems like a good idea but in reality most kitchen appliances will need a 13A fuse anyway so there would still be the inconvenience of pulling out the appliance to change the fuse.

BAS's suggestion of using unfused plugs overcomes the inconvenience of disconnecting outlet plates for testing but then there's the problem of invalidating warranties when cutting off standard plugtops to put on your unfused plug (or wire into your outlet plate)

Sooooo how about putting a solid link in a standard plugtop and a very permanent label stating that it must be replaced with a fuse if taken off the FCU circuit? Solves all the problems i reckon except the one where some idiot decides to ignore the warning label. Does it contravene the regs?

Some say as a RFC is rated to 32A so you can't use 20A rated switches.

Whoever said that must have been talking nonsense, by their logic you couldn't connect sockets or FCU's rated at 13A either

They are not specifically listed in BS7671 as an acceptable device to be connected directly to a RFC

Is there a list of devices which are? Just got the red book for xmas or are you just looking at appendix 15?

edited to correct typos

 

[Spark123]

I don't like the idea of using solid links in a 13A plugtop owing to the risk of it being unplugged and plugged in elsewhere. Once you start using technical terms on any notices then you run the risk of it being misunderstood or deliberately ignored.
At least with BAS's idea the appliance cannot be plugged in elsewhere as the plugtop is different.

 

[ban-all-sheds]

well if ur wanting to know i aint planning on doing at all, im just wanting to learn u know, its not as if i am going to be actually doing it, so somebody any help?

Learn to write properly and people might be more inclined to help you.

 

[ban-all-sheds]

there's the problem of invalidating warranties when cutting off standard plugtops to put on your unfused plug (or wire into your outlet plate)

It does not invalidate the warranty.

 

[Adam_151]

TBH, I don't see the discrimination thing as an issue... true it won't discriminate, but does it need to? the supply to anything else won't be interrupted, and anyway the fuse having cause to operate is not something thats going to be a regular event!

I feel like we are trying to come up with a solution for a problem which doesn't exist.

A 13A plug top fuse won't always discriminate with a type B 32A circuit breaker anyway!