On Monday, July 28, 2014 2:39:30 AM UTC+1, John Rumm wrote:
On 27/07/2014 21:40, wrote:
On Sunday, July 27, 2014 9:13:59 PM UTC+1, John Rumm wrote:
On 26/07/2014 22:38, ss wrote:

I have alongside some normal square pin 13 amp sockets some 5 amp round
pin sockets, the 13 amp works as normal but the 5 amp is switched on
from a light switch located elswhere.

The round sockets were installed maybe late 90s in an 80s house by the
previous owners, I was advised by an electrician that this was an old
format of being able to switch on table lamps from a light switch rather
than the wall socket.

Its not often seen, but its a perfectly valid and sensible arrangement
for those that life table lamps etc.

I have no idea which circuit they are on ie socket ring or lighting ring.

Could be on a lighting circuit or their own. If on the socket circuit
then there ought to be additional fusing elsewhere.

Now my question, I have recently purchased a 20 watt LED external
floodlight that comes with a 13 amp square plug, now I need to increase
the length of the cable and was looking to put a 5amp round plug on it
at the same time so I can use from the unused round pin socket.

Will this be safe to do so? With regard to Amps/wattage etc

As a rough guide, divide the wattage by the supply voltage to get a
typical current. So in that case 20 / 230 = ~87mA

Secondly I may purchase another 10 watt floodlamp so would it be ok to
run both from that 5 amp socket?

A 5A socket is good for loads up to 5 x 230 = 1150W

Its 240v, so 1.2kVA.

One ought to get into the habit of using the nominal 230V for
calculations IMHO.

Britain's target voltage is 240v, not 230. So if you want the correct answers, it needs to be 240. We have an odd situations now where what is in actual fact 240v is described as 230v.


NT

A 20w 0.15 pf load would consume 133VA, so the socket would be rated to power 9 of them. How many depends on the product pf.
Since the OPs total load - keeping things simple - is a fraction of an
amp, there seemed little point over doing it.