20amp or 13amp switches
- Thread starter barnies
- Start date
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If you use a switched FCU above the worktop then you can ditch the plug behind the appliance if space is tight and use a flex outlet (It can be a good idea anyway to have an outlet so there is not a fuse hidden behind)
20A DP switches can be used but the appliance fuse must remain somewhere after it.
20A DP switches can be used but the appliance fuse must remain somewhere after it.
It depends on the situation.
A 20A DP switch must only supply one single socket if it is on a circuit with a rating higher than 20A
13A FCUs can be used to supply more, but you are obviously limited to 13A by the fuse.
Also the fuse in the FCU may not provide discrimination with the fuse in the appliance plug.
It is up to the designer to decide what sort of switch is the most appropriate for that particular installation.
A 20A DP switch must only supply one single socket if it is on a circuit with a rating higher than 20A
13A FCUs can be used to supply more, but you are obviously limited to 13A by the fuse.
Also the fuse in the FCU may not provide discrimination with the fuse in the appliance plug.
It is up to the designer to decide what sort of switch is the most appropriate for that particular installation.
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Why can you supply only one item from a 20amp DP switch, and more with a 13 amp FCU?
With a 20A DP switch, say you connected a twin socket to the load side, there is potential to draw 26A (two 13A loads) through a switch rated at only 20A. This would burn the switch out.
If you draw a load higher than 13A through a 13A FCU all that will happen will be the fuse will blow, but the switch will not be damaged.
This can be useful where you might want to supply say four 3A loads from a single point of isolation.
If you draw a load higher than 13A through a 13A FCU all that will happen will be the fuse will blow, but the switch will not be damaged.
This can be useful where you might want to supply say four 3A loads from a single point of isolation.
Because if it supplied a double socket, the load could potentially be 26A which would burn the 20A switch out over time. With a single you are limited to 13A max.
Wish I could type faster 
You wouldn't have more than one appliance on a switch.
Also, I think you are confused between the current an accessory can carry and the fact that an FCU contains a 13A fuse.
The conductors on a Ring Final Circuit must be rated at a minimum of 20A so the same should apply to the accessories.
it is easiest to put appliances under the worktop if there is a 13A socket to plug them into (they come with a 13A plug)
so to avoid duplicating fuses, it is convenient to have a 20A DP switch above the worktop controlling an unswitched single 13A socket below.
so to avoid duplicating fuses, it is convenient to have a 20A DP switch above the worktop controlling an unswitched single 13A socket below.
I understand all that, but what i was asking was, why does some folk put 13amp switches up above the worktop rather than 20amp switches?
Just a point we may have missed - Are there any 13A switches?
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