RCD tripping

[333rocky333]

Latching is what it means they stay On with power failure, also known as Passive.
Non latching would need resetting after power loss also known as Active.

Fuseboard rcds are mainly Passive and latching.
Rcd spurs and sockets can be either.

 

[oldbutnotdead]

this could explain why it’s trips if there is no use for maybe 3-4 days, so voltage drop with naturally cause the rcd to trip from say large loads on at the same time?

And i’m guessing rcds and rcbos at the fuse board don’t trip when there is voltage drop as it isn’t ‘latching’

There shouldn't be enough drop in normal use (assuming the ring is a ring, no loose connections anywhere) to cause the thing to reset. The data sheet doesn't mention a number, you could do some experiments.
There may be some RCD/RCBO things in consumer units that latch but I've not met any- the standard is they stay set until a fault condition exists.
If the circuit powering the fcu is already protected by an RCD you can ditch your RCD FCU and put a normal FCU on.

 

[ericmark]

Have you measured the leakage? If the leakage is 15 mA then it would not take that much extra to trip. I know whole of this house is around 20 mA, spread between 14 RCBO's this is not a problem, but the insulation test showed into MΩ range so was rather surprised the leakage was this high, but of course the installation tester tests using DC, but we are actually using AC, so it does not show any capacitive or inductive leaking.

 

[oldbutnotdead]

Latching is what it means they stay On with power failure, also known as Passive.
Non latching would need resetting after power loss also known as Active.

Fuseboard rcds are mainly Passive and latching.
Rcd spurs and sockets can be either

@electrified I may have misled you on what that fcu does on loss of supply. Try it and see what happens.

 

[electrified]

There shouldn't be enough drop in normal use (assuming the ring is a ring, no loose connections anywhere) to cause the thing to reset. The data sheet doesn't mention a number, you could do some experiments.
There may be some RCD/RCBO things in consumer units that latch but I've not met any- the standard is they stay set until a fault condition exists.
If the circuit powering the fcu is already protected by an RCD you can ditch your RCD FCU and put a normal FCU on.

RCD can’t be ditched but there probably will an rcd in cu in the future. this is really bizarre, but what i will do is L+N-E with everything connected, even though i don’t think it can be the downlighters as no earth present.

 

[electrified]

Have you measured the leakage? If the leakage is 15 mA then it would not take that much extra to trip. I know whole of this house is around 20 mA, spread between 14 RCBO's this is not a problem, but the insulation test showed into MΩ range so was rather surprised the leakage was this high, but of course the installation tester tests using DC, but we are actually using AC, so it does not show any capacitive or inductive leaking.

can’t be leakage as it trips after a few days when nothing is on and no leakage to earth that is bypassing the rcd to the neutral via a short as IR tests come back good

 

[ericmark]

IR tests come back good

But the IR test is done with DC, and your using AC, so it may be a good indication, but only way to be sure no leakage is to test using AC, i.e. clamp on meter.