Does My Light Switch Need A Fuse

[DeludedAussie]

Hi

ON a previous thread I was told that I need to put a 3A fuse between the power supply and the light switch

I want to understand exactly why. My switch has a 10A fuse built in right? So if there is a surge of power the light switch will blow. Is that correct?

Why do I need a fused switch exactly

 

[phatboy]

A light switch doesn't have a fuse, its just rated to safely operate a load of up to 10amps.

You only need to fuse it if its on a circuit of above 10amps, like a ring main for sockets. If its on a lighting circuit you don't need a fuse.

 

[ericmark]

What makes you think there is a 10A fuse built into your light switch?

Most standard light switches will have the maximum breaking current marked on them this figure it the maximum size of the supply fuse that should be used it does not have the fuse built in.

Light bulbs should have built in fuses to stop the short circuit caused by ionisation when they blow but this is only with a tungsten bulb and often not fitted by manufacturer when missed if the bulb blows and ionisation takes place (the big flash when they blow) then without a fuse or MCB of 6A or less likely the solder contacts will melt on the bulb and weld the bulb into the bulb holder meaning instead of replacing the bulb you have to replace the whole fitting.

A switched fused connection unit looks very like a light switch and does have a fuse built in.

 

[ban-all-sheds]

My switch has a 10A fuse built in right?

WRONG!

the switch has a 10amp fuse already - is that enough?

Your switch has no fuse.

Oh dear. I don't think you are cut out for this.

He's right - not only do you not have a clue what you are doing you aren't taking any notice of what people are telling you.

 

[Taylortwocities]

And why, oh why, did you start a new topic?
Were you hoping to get different answers from those already given on //www.diynot.com/forums/electrics/taking-power-from-socket-for-light-switch.355588/

It just wastes everybody's time..

 

[Chri5]

A lighting circuit from a fuse board is rated at 6 amp or sometimes 10 amp.

So a light fed from that circuit is restricted to 6/10 amp.

A light feed from a socket circuit, the socket being part of a ring is rated at 30 amp.
Without a fuse in the middle between the socket and the switch for the light that lighting wiring and fittings is opened up to the full 32 amp of supply.

So more ouch if something goes wrong and a cable feed that at best is 50% under capacity for the potential load.


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