BS 1363 13A Socket Continuous Max Load

Sparkingchip: 
 

sparkiemike: 

At a recent Elex “seminar” Darren Staniforth from Scolmore made a comment that BS1363 socket outlets were only tested for 8A continuous load. This was news to me because my 1995 version of BS1363-2 says for the Temperature rise test the connected load will be 14A for a minimum continuous period of 4hours or longer until stability is reached and max duration of 8hours. 

 

The 14 amp test load is beyond the rating of the socket, plug and any appliance that should be connected.

So the test covered misuse of the socket by someone using a multiway socket adapter, which is something I see very frequently, but modern adapters are fused so it is a throwback to the nineties, after nearly twenty years there may be an assumption that people have sufficient sockets in their homes, but that is far from true, I regularly see things like the kettle, toaster and microwave all plugged into a single socket using a multiway adapter or the washing machine and dryer.

Having said that how long does it take for a 14 amp load to blow a 13 amp fuse?

In my view testing at 14 amps is reasonable for a plug and socket rated at a nominal 13 amps. Not for deliberate misuse, but to allow for manufacturing tolerances and mains voltage variations. Consider an appliance designed to use 13 amps but that actually uses 13.5 amps due to manufacturing tolerance at nominal voltage, and that uses 14 amps at 250 volts which is within the permitted range.

13 amps should be regarded as the NOMINAL rating and not as an absolute maximum. A bit like motor car tyres that are marked “110 MPH” planned use at a significantly higher speed would be foolhardy. BUT I would not expect the tyre to burst or come apart at 115 MPH that was reached briefly and inadvertently due to a speedometer reading 5% low.

Sparkingchip: 
 

sparkiemike: 

At a recent Elex “seminar” Darren Staniforth from Scolmore made a comment that BS1363 socket outlets were only tested for 8A continuous load. This was news to me because my 1995 version of BS1363-2 says for the Temperature rise test the connected load will be 14A for a minimum continuous period of 4hours or longer until stability is reached and max duration of 8hours. 

 

The 14 amp test load is beyond the rating of the socket, plug and any appliance that should be connected.

So the test covered misuse of the socket by someone using a multiway socket adapter, which is something I see very frequently, but modern adapters are fused so it is a throwback to the nineties, after nearly twenty years there may be an assumption that people have sufficient sockets in their homes, but that is far from true, I regularly see things like the kettle, toaster and microwave all plugged into a single socket using a multiway adapter or the washing machine and dryer.

Having said that how long does it take for a 14 amp load to blow a 13 amp fuse?

In my view testing at 14 amps is reasonable for a plug and socket rated at a nominal 13 amps. Not for deliberate misuse, but to allow for manufacturing tolerances and mains voltage variations. Consider an appliance designed to use 13 amps but that actually uses 13.5 amps due to manufacturing tolerance at nominal voltage, and that uses 14 amps at 250 volts which is within the permitted range.

13 amps should be regarded as the NOMINAL rating and not as an absolute maximum. A bit like motor car tyres that are marked “110 MPH” planned use at a significantly higher speed would be foolhardy. BUT I would not expect the tyre to burst or come apart at 115 MPH that was reached briefly and inadvertently due to a speedometer reading 5% low.