RCD tripping a mystery

[I2C]

Hi

I have an issue with random RCD tripping. It happens at different times of the day and no obvious cause (ie particular piece of equipment).

All connected equipment has passed recent PAT test and IR on circuit looks ok (>600M PE).

A lot of the connected equipment has thermostat controlled heating elements - wax melting machines etc (it’s a beauty salon).

Had a thought that if a couple of RCD protected socket adapaters were put on the sockets and checked whenever it tripped, Does this sound like a reasonable albeit long winded way of narrowing down the fault??

Any other suggestions??

RCD Socket-Outlets
If you have socket-outlets which contain an RCD, it's important to ensure adequate discrimination has been provided. For example, if a socket-outlet containing a 30mA RCD is installed on the same circuit which is protected by another 30mA RCD at the consumer unit; it's possible that either of the RCD's will trip. Therefore, it's important to ensure discrimination is provided (delayed/higher value RCDs fitted at the source).

Earth-Leakage
Some appliances can 'leak' current to earth during use, which is known as an 'earth-leakage'. Often, the earth-leakage value is very small and insignificant on it's own, however if there are many appliances used which all contribute earth-leakage, the total value will increase and can trip a RCD (normally rated at 30mA).

RCD Testing
It's worthwhile performing tests on the RCD to ensure correct operation. This can include a ramp-test to determine the current required to trip the RCD and confirm functionality.