RCD is it a problem with RCD or is it just imbalance?

[arturas]

So that's what happened,it's all new house re-wire ,shiny hagger 18 way dual RCD CU.Everything is tested and energised apart from bathroom lights,I was changing the switch,bathroom msb was off,cutted the feed and expected RCD to trip but nothing happened,usually they do trip straight away. Then tried even to touch neutral and earth together but nothing,all RCD trip times is perfect,ramp test was 22miliamp,zs at the last light is 0.8,r1+r2 is 0.60 ,ze at cu is 0.15 tncs supply,then tried to do the same with the ring,switched msb off linked ne and nothing,once you set tester on continuity test,on dead sockets between neutral and earth it does trip straight away,I guess nothing to worry about,or I'm wrong?thanks for your opinions.P.S. IR is 400 ne le,and >999 with the switch closed.

 

[Knobhead]

Do you know what a DP switch is? You should do by now.

 

[arturas]

If you're saying about rcd,then I do know how it works,there's no other DP switches in the whole circuit.

 

[spark 68]

Some RCD's need a small amount of current (load) running through them before they will trip.

I have noticed this before, particularly on TNC-S systems, so long as your RCD tests are ok then this nothing to worry about

 

[arturas]

Thanks,just wanted to see if I'm thinking the right way