IMO, although our home socket is rated at 13A (i.e. 2990 watts), it does not mean they are safe to draw such high current.
Examples:-
1) Water heater and window air-con. These equipments are difinitely lower than 2990w, but hdb requires isolated 15A power point for them. If you hook them into a normal 13A point, you'll either have a trip or burning socket.
2) New Hdb flat has rule for pre-installed air-con point. If I'm not wrong, the compressor cannot be above 11-13A. But they're 15A point.
3) Electronic designer normally select components that is rated above the circuit requirement as far as cost allowed. Any electronic hobbist or student will know this.
I think I've read it somewhere. As a general guide, never exceed 70% of the rated power. i.e, don't exceed 2,093 watts (2990 * 70%) on a 13A point
One very important thing, use good quality multi-plug. Those cheap ones have very bad contacts which will create sparks and heat.
Just my 2 cents