Max wattage of a electric socket

[ey143]

I was looking at some nice LightwaveRF sockets. I read somewhere that it offers up to 3000 watts. is this normal? Seems a little low to me. I mean some electric heaters are 3kw, so this would be pushing it to the max. Also is that 3kw per gang or for both gangs?

http://www.vesternet.com/lightwaverf-2-gang-13-amp-socket

 

[securespark]

You are best asking the manufacturers if you have a query about the maximum rating/ loading of their products.

 

[JohnD]

The standard for a UK plug, and a UK socket, was required to be adequate for a 3kW load because, when it was introduced, that was the biggest load that was expected in a UK home (it was at the time a 3-bar electric fire).

At the time, it was not expected that you would use two such loads in the same room, never mind plugged into one outlet, though it was anticipated that you might want a trivial load such as a table-lamp at the same time, and double sockets are fine for two light loads.

We now have many more 3kW appliances, such as dishwashers and washing machines, though with the introduction of central heating and better insulation, 3kW portable heaters are less common. However the standard has not been altered. You should not plug two 3kW appliances into a double, because this will exceed its rating if used at the same time. A washer and a tumble drier together are common causes.

As Securespark mentions, some manufacturers design their sockets to surpass the British Standard. These may not be the cheapest.

 

[ey143]

Yes, its mainly because of the wireless home automation built into them which has pushed the price up. In fact, these normally are £30 so just bought a few whilst they were at a cheaper price.

So the 3000 watts you refer to, seems to be average / normal then? Is wattage you refer to across the two gangs or each gang? Also when you use the example of a washing machine and dryer at the same time, does it make any difference if they were plugged into two different sets of double sockets and both running together? Ultimately they are drawing power from the same ring mains in the kitchen.

 

[Spark123]

Nothing wrong with using two spearate sockets for washer and dryer, even two single sockets located together. It is when the are plugged into the same double socket things can get a bit toasty.

 

[securespark]

Is wattage you refer to across the two gangs or each gang?

I thought John had answered that question. If you want a more definitive answer ring the manufacturers.

 

[JohnW2]

I was looking at some nice LightwaveRF sockets. I read somewhere that it offers up to 3000 watts. is this normal? Seems a little low to me. I mean some electric heaters are 3kw, so this would be pushing it to the max. Also is that 3kw per gang or for both gangs?

If that 3000 watts (about 13A) for the LightwaveRF socket refers to the total load across both outlets (possibly true, but, as has been said you would have to ask the manufacturer), then that is the same as a standard single socket, but less than a standard double socket. Although there is uncertainty and some controversy as to what is the maximum load (across two outlets) for a standard double socket, BS1363 requires that they should pass a temperature-rise test with a total of 20A being drwan (across both outlets). It would therefore seem that the maximum permissible load is probably at least 20A. One certainly hears reports of problems arising if/when people try to draw 26A (2 x 13A) from a standard double socket.

The two outlets must each be cable of supplying 13A (3 kW). Assuming that they can be switched (wirelessly) separately, that means that the 'electronic switchery' for each must be capable of coping with 13A. It therefore is not a foregone conclusion that they can only safely supply a total of 13A (across both outlets) - so, again, you would have to ask the manufacturer.

Kind Regards, John

 

[winston1]

One 13 amp socket at the normal 240 volts should carry 3120 watts. But they can get warm at this load for any time mainly due to the fuse in the plug getting hot. A double socket is generally rated at 20 amps split across both sockets which equates to 4800 watts.

 

[securespark]

What if the voltage is 216 or 253V?

Or 230V?

 

[winston1]

What if the voltage is 216 or 253V?

Or 230V?

The 13amp socket was developed with a voltage of 240 volts in mind. If the voltage varies the max power will also vary. With a fixed 13 amp load it will vary in proportion to the voltage. With a fixed resistive load it will vary in proportion to the square of the voltage change. Of course if the voltage rose above 240V the current would rise above 13 amps which would be an overload anyway.

But you know all this anyway. All the OP wanted to know was 3000 watts normal and the answer really is yes.

 

[securespark]

So why didn't you say that? You had to bring 240/ 3120 into the equation.

 

[bernardgreen]

If you are controlling a 3 kW appliance from a remote location from where you cannot see the appliance how can you be sure it is safe to turn on the appliance ?

 

[JohnW2]

All the OP wanted to know was 3000 watts normal and the answer really is yes.

IF (we don't really know) the "3000 watts" relates to the total load on both outlets of his double socket, then that surely is not really "normal" (for standard sockets)? As both you and I have said, despite a few dissenters, most people believe that most double sockets are 'rated' to carry at least 20A (across both outlets).

Kind Regards, John

 

[JohnW2]

If you are controlling a 3 kW appliance from a remote location from where you cannot see the appliance how can you be sure it is safe to turn on the appliance ?

In these days of new-fangled technology, it's far from impossible that a person could "see the appliance" from a remote location

However, more seriously, your point is obviously valid - but it is not specific to a situation in which a human being controls the appliance from a remote location. It is equally true when an appliance is controlled by a time switch or other 'control system', if the premises are unoccupied when the appliance is turned on.

Kind Regards, John

 

[stillp]

A double socket is generally rated at 20 amps split across both sockets which equates to 4800 watts.

The cheap ones often are only rated for 20 A total.