fcu or 20a dp switch for kitchen appliances

[JohnD]

You beat me to it, John!

and is your duck flying too?

 

[ban-all-sheds]

The terminals on a 20A switch might only be rated at 20A, but they are on a supply fused at 30A.

Ever looked at what the terminals on a BS1363 socket outlet are rated at?

 

[JohnD]

nope

is the answer 32A?

or 13A?

Fing will know

 

[FingRinal]

John,

I pretty much agree with what you are saying, but why not use a 32A DP switch? Same size, same looks etc. Even the IET thread is rumbling on and off...

This one still causes gnashing of teeth everytime it crops up. So I only fit MK 32A DP switches now, or MK SFCU (preference). I don't like Grid switch arrangments and would never put one on a ring - certainly not one I hadn't installed.

 

[ban-all-sheds]

20A...

(disclaimer - my copy is BS 1363:1984 - it may have changed in later versions)

 

[securespark]

Fing, I can't see a problem with 20A switches. The 20A rating refers to its switching ability. As Ban has said, 1363 sockets are rated at 13A, but that does not stop us wiring them into 32A circuits. Each outlet is designed to handle a 13A load, just as a 20A switch can handle a 20A load. If you feel better using 32A switches, fine, but myself and many others are confident in our use of 20A switches. If you think that for that reason I don't "take the issue of ELECTRICAL SAFETY very seriously", then so be it...

BTW, you haven't answered my question yet. Could you, please?

 

[securespark]

You beat me to it, John!

and is your duck flying too?

Just got it!!


Yes, it is!

 

[FingRinal]

Fing, I can't see a problem with 20A switches. The 20A rating refers to its switching ability. As Ban has said, 1363 sockets are rated at 13A, but that does not stop us wiring them into 32A circuits. Each outlet is designed to handle a 13A load, just as a 20A switch can handle a 20A load. If you feel better using 32A switches, fine, but myself and many others are confident in our use of 20A switches.

I haven't said that I disagree with what you say. But, the argument won't go away (on the whole and not just here). When you do something for a living, in my opinion, it's only right and proper to do it in full compliance with applicable laws, regulations and guidance and to cover your backside. That doesn't mean I am right and it doesn't mean I am wrong. I've seen loss adjustors look for the slightest thing to transfer liability to someone else. Since the floods, insurance companies are tightening their belts like never before....

So should one of them put you on the spot about why you did something the way you did, is it better to spout forth a cascade of Regs and justification or shrug the shoulders and admit it's because everyone does it that way. I prefer the former and to make THEM prove it rather than me DEFEND it.

If you're a DIYer, it might matter less. But I think the times are a changing.

Anyway, I'm signing off for tonight. I've heard that the legendary blind Canadian guitarist Jeff Healey has just passed away aged 41 and I'm going to spin a track or two. (He was the blind guitarist in the movie Roadhouse with Patrick Swayze). Saw him live once...best since Stevie Ray Vaughan....

 

[ban-all-sheds]

Anybody got access to a copy of BS EN 60669-1: 2000 ?

 

[securespark]

Sorry, Ban, no.

Fing, before you go, can you answer my question?

Don't want to be labelled a politician, now do you?

 

[Qedelec]

Connecting a single outlet to the 20A DP will ensure a max of 13A is drawn.

 

[GaryMo]

That's not the main issue, it's the current passing through the feed side terminals, not through the switch contacts.
There's been a couple of threads on the other forum where a poster claims to have asked certain manufacturers if their 20A grid switch is suitable for connection to a 32A ring final circuit. They wouldn't commit either way.

Would you use a 20A junction box to connect two 2.5mm t&e cables together on a 32A ring final circuit? Same thing.

 

[Spark123]

The terminals on a 20A switch might only be rated at 20A, but they are on a supply fused at 30A.

Ever looked at what the terminals on a BS1363 socket outlet are rated at?

Are they not rated for the full 32A? If they aren't then surely they won't be suitable for use in a 32A radial circuit

 

[ban-all-sheds]

[code:1]Table 5 - Loading of socket-outlets for temperature-rise test

Type of Plugs with Balance Total load
socket connected loads of load on supply cable

A A

Single 1 × 14 A 6 20
Twin 1 × 14 A + 1 × 6 A - 20
Multiple
(fused) 1 × 14 A + 1 × 6 A - 20
Multiple
(unfused) 2 × 14 A - 28

[/code:1]

There are no mentions in BS 1363:1984* of any tests to show that a socket can withstand 30 or 32A on the supply cable....

*Not the latest version

 

[BS3036]

Mmm. Anything about the csa capacity of a terminal for inserted wires?

This notion must have come from somewhere. As a matter of interest, an appendix in the 17th Edition shows ring and radial final circuit illustrations, with FCUs being allowed if they conform to BS 1363-4.

EDIT: Oh, I was also going to add: Why would the terminals need to be rated at 32A when the wire going in and out of them isn't?