Agree with Doc Hudson.
As stated in the OSG 11.1 "The tests are made on the load side of the RCD,as near as practicable to its point of installation and between the line conductor of the protected circuit and the associated circuit protective conductor. The load supplied should be disconnected...
Cheese wire for me(and the students I teach), however there is a train of thought that by doing this method you MAY "stretch" the CPC therefore affecting its current carrying capacity in the event of a fault, alledgedley!
Inspection and testing, fault diagnosis and fault rectification. IMO the 303 is much easier than the 302, so if you have passed the 302 already you shouldn`t have any dramas with the 303.
Ayup and howdy,
My names elec dept and I`m an alcoholic. I am in the right place aren`t I?
Been a spark since 1987. Now moved to the dark side and teach/instruct(sort of!).