20amp or 13amp switches

[barnies]

Just a point we may have missed - Are there any 13A switches?

13 amp switch fused ?

 

[EFLImpudence]

That was my earlier point.

It has a 13A fuse in it to protect the load cable.

I agree the terminology is poor because you could put a 3A fuse in it but that wouldn't alter the construction of the accessory.

The FCU itself (its terminals) still has to carry the current on the circuit so will be rated at 20A.

There are 10A switches for use on lighting circuits.

 

[JohnW2]

The FCU itself (its terminals) still has to carry the current on the circuit so will be rated at 20A.

One would obviously hope so - and. looking at the terminals, they are clearly quite capable of coping with at least 20A. However, as for 'rating' and just out of curiosity, I've just had a look at the backs of several makes, and they all have '13A' embossed on their moudlings

Kind Regards, John.

 

[EFLImpudence]

The FCU itself (its terminals) still has to carry the current on the circuit so will be rated at 20A.

One would obviously hope so - and. looking at the terminals, they are clearly quite capable of coping with at least 20A. However, as for 'rating' and just out of curiosity, I've just had a look at the backs of several makes, and they all have '13A' embossed on their moudlings

Oh, right, well I stand corrected but I'm not sure what that means except that there can be no more than 13A going 'through it' unlike 13A sockets, especially doubles.

I could not find a '13A' switch without a fuse.

As that is the case then, for what, specifically, would a 20A switch be intended - a 4.5kW appliance on a radial circuit?.

tfb

 

[JohnW2]

Oh, right, well I stand corrected but I'm not sure what that means except that there can be no more than 13A going 'through it' unlike 13A sockets, especially doubles.

I don't know what it means, either - probably just as you suggest and, as I said, almost certainly nothing to do with how much current can pass through conductors connected to its terminals when it's wired into a ring (certainly 20A and, in those silly extreme cases we often find ourselves discussing, theoretically anything up to nearly 32A).

I could not find a '13A' switch without a fuse.

I don't think such animals exist, or ever have existed - at least in standard accessory ranges.

As that is the case then, for what, specifically, would a 20A switch be intended - a 4.5kW appliance on a radial circuit?.

Indeed - and, by the same token, for what, specifically, would a 10A switch (millions of which exist in 5A/6A lighting circuits) be intended? The answer to both questions may simply be that 10A and 20A are round numbers which give a bit of a safety margin beyond the currents they nearly always have to break?

Kind Regards, John.

 

[JohnD]

commercial and industrial lighting circuits are often rated at 10A as they can be much bigger than domestic ones. The 10A switches and lampholders are suitable for that. There's no need to make switches and lampholders in both a 5A and a 10A rating so the 10A ones are universal.

There are only a few 5A rated lampholders on the market, usually ones with SBC or SES fitting, and these cannot be used on a 10A circuit.

 

[JohnW2]

commercial and industrial lighting circuits are often rated at 10A as they can be much bigger than domestic ones. The 10A switches and lampholders are suitable for that. There's no need to make switches and lampholders in both a 5A and a 10A rating so the 10A ones are universal.

Quite - and very probably a corresponding reason why 20A switches are universal, to avoid having 13/15A ones and 20A ones.

Mind you, in more general terms, I still question the need to have a switch (or other accessory) rated according to the capacity of the circuit rather than of the load it is switching. Lampholders are even sillier - even on a 10A or 16A lighting circuit, there's no way that a lampholder needs to be 'rated' even at 5/6A, let alone 10A or 16A!

Kind Regards, John.