Are you overload your socket? Quiet high your load. And you using extension socket too?

If without the load, empty socket or wire takeout from the socket, the mcb and the elcb stil trip? With the above method, takeout the wire from the mcb and test with multimeter to N, does it beep?

If this 2 method show trip and beep, than the wire is short circuit somewhere. There is no other method to know where the wire short if didn't takeout the whole wire.

Use separate wire and mcb for each aircon and pc. If you make a new wiring. If you lazy hacking, than just use the Cable trunking.

If you want to run the cable outside but worry hack to another cable, use a device call something like volt stick. It sense the cable magnetic field and give out light and sound. I use it before on checking conceal wire.