Safe isolation on lighting circuit am2

[Jakegood]

hi everyone,

When demonstrating safe isolation on the lighting circuit on am2 do you operate the switches and test each time you operate.
Or, just operate the switches in every position then just test once at the 2d light fitting?
Also, when commencing a ZE test would you recommend setting the megger test on a 2 lead high or low. I’m pretty sure I was advised to put it on low. Just want to double check

Cheers

 

[telectrix]

for safe isolation of any circuit, you switch off the MCB and lock off. then test with approved voltage tester. L-N , L-E, N-E.

for Ze always use hi current 2 lead.

 

[Jakegood]

That’s fine. But, just wanted to know if you test at the 2d fitting with the switches in every position e.g three times. Or, just switch the switches in every position to show the light does not come on then test at the fitting once?

I’m just sure I was told to test on low because of the RCBO? May be wrong though

 

[Richard Burns]

If you have safely isolated the lighting circuit (or indeed the whole DB) and then tested at the board that the light circuit outgoing cable is dead and tested at the light fitting that it is dead; then, no matter what switching arrangement you have, any one switch operated should change the state of the lights and a repeat test at the light fitting should cover all possibilities. (Then check to ensure the voltage indicator is still working on the proving unit.)

As there may be an RCD protecting the supply before the test bay use the low current test to test Ze or Zs.
Though Tel is right in general normal practice that Ze, tested at the origin of an installation, should not have an RCD on the supply so a high current test is best.

 

[Jakegood]

On the test the require you to just isolate the lighting circuit notbtbe whole board. So, identify the breaker turn off and lock off. Then switch switches in all positions, then test at fitting. (Obviously testing voltage tester with proving unit before and after).
They want you to demonstrate working on a one circuit while the rest of the installation remains live