Rcd test with dimmer switches

[hutch6447]

I have just tested a function room everything fine all the lights trip at the points ceiling rose/plug & Play on an rcd test, but when testing at the light itself all the lights that were on normal grid switches tripped fine, the 2 that were on dimmer switches didn't trip on rcd test but as I said tripped at the plug & Play.

Do dimmer switches mess with the rcd test and if you bypass the dimmer and it performs OK on rcd test would the rcd trip when dimmer re installed?

 

[Sparky Ninja]

Theoretically no, as it's alterations to the current flow that would operate the RCD and normally the dimmer is just a variable resistor with the current remaining a constant. However I have experienced some dimmer switches, such as IQ ones do similar to this.

Why are you testing the RCD at all these points though? Why not just do it at the device?

 

[electric will]

I always rcd test at the end of the circuit, normally where I get highes r1 and r2 from, surly you can't just test the rcd in the board for every circuit.

 

[Sparky Ninja]

You test the device and not the circuit, so the board is a common location for many.

 

[electric will]

So on your eic you just test rcd 1 and write that result in all circuits protected by rcd 1. Dual rcd board I mean

 

[Sparky Ninja]

You write the readings to all circuits protected by the RCD. Or you could simply insert the RCD on the schedule and record the times there, as long as it is clear which circuits are protected by the device when it is reviewed.

 

[electric will]

Searched the forum and it seems some people do it one way and some the other, might start just testing at the rcd though, will be a lot quicker, and why shouldn't it be a satisfactory test, all dead tests would ave been done on the circuit.

 

[hutch6447]

Yes have tested the rcd at the 2 x ring mains and it trips fine, tested on lighting circuit at the plug & plays and trips fine but when testing at furthest point on the down lights the runs that are on normal grid switches trip but the ones on dimmers don't.

Just a bit concerned that if anyone starts fiddling round up top the runs on the dimmerable switches, will it trip rcd as the tester we had was 1720 and on the dimmer switch runs it came up with trp but everything else was fine.

The dimmer grid switches are zeno's.

 

[Guitarist]

The "recommended" way of testing an RCD is at the device with loads disconnected. This eliminates any circuit leakage from the test. The other tests you have carried out on said circuit will prove that it is safe.
That said, I always like to test at 1 point afterwards for my own peace of mind

 

[hutch6447]

Exactly so will it trip rcd with these stupid dimmer switches on I dont know tested at source, tested at every plug & play click box and its fine! when its going through them dimmers it messes the test up. Tried all the runs on normal grid switches and rcd trip test works fine replace the dimmers back to square one.

That is my concern with the dimmers in will rcd trip!

 

[telectrix]

any electronic device in a circuit is liable to affect the RCD test. if it trips on other circuits and/or at the RCD itself, then you can safely assume thast it's working within it's parameters.

 

[hutch6447]

Thank you thats te answer I was looking for cheers mate!

 

[Guitarist]

I love how people are only grateful for the answers they want to hear

 

[Guest55]

Exactly so will it trip rcd with these stupid dimmer switches on I dont know tested at source, tested at every plug & play click box and its fine! when its going through them dimmers it messes the test up. Tried all the runs on normal grid switches and rcd trip test works fine replace the dimmers back to square one.

That is my concern with the dimmers in will rcd trip!

So youre rcd testing at nearly every point on the circuit ?
with loads connected ?
good grief lol.

 

[electric will]

Be a very very long test