200w security light - connect to lighting circuit.

Probably, unless it is already close to the limit. The total circuit will usually be rated for about 1200W. So go round and add up what is on it. Count 100W for each fitting unless its actual load is greater (in which case count that)

Thank you. I will do that then, as the load on the circuit is way below its limit, even with all lights on.

I think the reason I was hesitant is that I remember reading that the maximum wattage of bulb that one should put in a regular ceiling light is 150 watts... But I guess that's because the cord that dangles down from the rose to the bulb-holder is typically thinner than the 1mm cable of the main part of the circuit...

Hank

The limitation is usually getting rid of the heat. The thinnest pendant flex will take 3A which is nearly 750W, so power availability is not much of a problem, but a 150W bulb will get anything close to it very hot.

Indeed - an interesting problem when I made a snooker table light, which used 2 x 200W lamps, many years ago.

Colin Bignell