Help with a fault question?

[Adam byrne]

So for college I'm having to fill out a job form and answer questions on a job I've done, for this form it's TESTING.

As I'm a lowly data apprentice Doing an electrical apprenticeship I'm not too sure on some things

So the fault I've decided to write about is one time where I had a full lighting panel (control4) with 8 control packs with 8 circuits each, each pack had it's own 6a mcb and were all on a single 32a RCD, whenever you flicked the rcd it tripped instantly, now I know this is due to the small amount of earth leakage each pack and quickly we changed to RCBOs , the only thing is the question asks "What tests did you perform" and I'm stumped, I can just say "I just knew it was earth leakage"

I would appreciate any help

 

[Pete999]

Use an earth leakage clamp meter on the cpcs of each circuit, to total the cumulative earth leakage

 

[Adam byrne]

Cheers mate this helped a lot, also to resolve this surely it's as simple as switching to RCBOs?

 

[Pete999]

Cheers mate this helped a lot, also to resolve this surely it's as simple as switching to RCBOs?

Yes swapping the CBs for RCBOs will do as you say swap the Main RCD to a main switch, will stop the cumulative effect of all the earth leakages.

 

[Adam byrne]

Yes swapping the CBs for RCBOs will do as you say swap the Main RCD to a main switch, will stop the cumulative effect of all the earth leakages.

And what legal tests do I have to do after
Question states "when the fault was corrected what did you do"

 

[ruston]

Fill out relevant test forms for the circuits altered.

 

[Adam byrne]

Fill out relevant test forms for the circuits altered.

Would that be a minor works?

 

[ruston]

If you have altered the board and 8 circuits I would be inclined to issue an EIC .

 

[Adam byrne]

If you have altered the board and 8 circuits I would be inclined to issue an EIC .

I think I've got it all, appreciate the help from both of you just made 8 hours at a desk into 3 max

 

[Pete999]

If you have altered the board and 8 circuits I would be inclined to issue an EIC .

Agreed with Ruston, but the Regulations only require a MNWC for circuit alterations.

 

[ruston]

@Pete999 I agree, but depends on what he has done . And by the time he fills those forms and tested the circuits it would be as prudent to issue an EIC in my opinion .
Edit . Last paragraph.

 

[Pete999]

@Pete999 I agree, but depends on what he has done . And by the time he fills those forms and tested the circuits it would be as prudent to issue an EIC in my opinion .
This was a real installation as I read it , not a mock up , so I would expect it was more than minor works.

Like I said Ruston I agree with your answer,just making the OP aware of what 7671 says about circuit alterations, swapping all those CBs for RCBOs is more. than Minor works, as it's a college type exorcise you never know what the examination body requires.

 

[Baddegg]

If you changed the mcb to rcbo wouldn’t you test the rcbo times?