A washing machine (Hotpoint Aquarius WMAQF 641 P) and a tumble dryer (Candy GCC 590NB-80), which are well used in a hair salon, have a problem that the RCD regularly trips. The machines are plugged into a double socket which is supplied as a spur through 1.5mm flex cable in mini trunking. However, this is connected to a socket on the ring by a plug. I can't easily find the manufacturers power usage (2.1 and 5.2Kw?), which probably fluctuates a lot, depending the machine cycles. I plan to change the flex to the spur or extend the ring to the spur with 2.5mm T&E. Has anyone any other suggestions and a reason why the RCD trips?