Hi mate I did my test about 3 wks ago, below is a bit of info I've copied and pasted that I wrote to another guy hope this helps a wee bit!
Testing:When doin your insulation resistance on the light and power db in the main switch room you have to disconnect the rcd socket remove lamps and starter from fluo.
Also insulation resistance on outgoing circuits on the main 3ph db in the indusrial installation disconnect the main neutral and turn the motor isolators to off, all mcbs on. Remember there will be 10 tests on the 3ph board (phases-earth, phases-neutral,neutral-earth and between phases) I did this and it seemed to work.
Other tests before this are quite straight forward, polarity, continuity ect, I was using the on site guide to help me along, don't be shy to use it for methods.
Live testing: Aye you have to use the cover, he'll help you fit it aslong as you recognise it's use. Ze of the power and light db in the main switch room disconnect the main earth for this. You'll probably have to do Zs at various points in the installation also such as the sockets.
RCDs test 1/2x, 1x and 5x on both sides of the wave form 0-180, record the highest values.
He'll ask you to find maximum earth fault values in the guide for certain results you get but I think they're quite easy to find. There was one result I got it was 10.88 or somethin and he asked questions like was it acceptable and if not why not? because it's to high and the breakers won't trip
