RCD's and Dimmers??

[Lillpete]

Had a bit of a wierd one today ?:| we were testing a lighting circuit which we had made some alterations to. We fitted a wylex RCBO so obviously needed to do RCD tests, however the Fluke tester was giving strange readings?? I had already checked R2/Insulation/Loop (all fine) but RCD was saying error 4 first few tests then it just clicked through the 1X/2X etc like it was testing but gave no results. We double checked that we had the right neutral in the RCBO and everything else we could think of and finaly tried testing at the light switch (ie before the dimmer switch, this then tested out all OK :^O but still wouldn't test at the light??

Has anyone else had a problem testing RCDs downstream of a dimmer switch as I've not noticed this before.

 

[dean mac]

ive read read somewhere error 4 is when the mains is to noisy u have to press arrow button down to obtain reading i think

 

[SPECIAL LOCATION]

Yes dimmers can give problems.

I always take dimmers out of your circuit..

dependant upon the electronics inside it you can get all sorts of weird and wonderful readings.

 

[green-hornet]

You should always remove dimmers before testing, as stated above you get some weird readings if left on the circuit and the IR tests will not work.

 

[kme]

Mr. Mac is correct, r.e. the fluke. An error 4 is still providing a reading, albeit noisy. usually down to a loose neutral, assuming r1r2 and ins. tests were ok.

 

[Lillpete]

So you press one of the arrows and it will give the reading it managed to get??

Insulation wise I presume the dimmer stops the DC getting through to the cabling from the switch to light so anything past the loops doesn't get checked? is that what your saying??