rcbo testing

[madrid]

had a job today ,fitted a new board including 5 rcbo's.newlec own brand which is wylex.All rcbo's tested fine apart from the ring circuit 32 amp one.Tripped within the time on 1xIn on both occasions tripped at a time greater than 40ms and then would not trip on the final test.changed the rcbo for a new one still got same result.Anybody got any idea what could be causing this.I did a pir first so all readings ok.loop impedance fine ,ring continuity fine.

 

[Deleted member 26818]

Wher are you testing from?
Are all loads on the RFC disconnected?

 

[madrid]

Testing at various points on ring .quite a few loads still plugged in but not switched on.

 

[IQ Electrical]

Testing at various points on ring .quite a few loads still plugged in but not switched on.

You might still have capacitors in circuit or even capacitive coupling affecting the tester display time.

This is why you should test at the terminals of the device with all load disconnected.

 

[Electro-tech]

Was there not a Post on here a while back where the OP made up a short fly lead for the test.????

 

[T&Earth]

Hi Guys

When I recently tried testing at the terminals of a RCBO the terminal screw was so far back and hole too small I had to test at socket outlet.
T&E

 

[malcolmsanford]

Hi Guys

When I recently tried testing at the terminals of a RCBO the terminal screw was so far back and hole too small I had to test at socket outlet.
T&E

I used to have an old neon driver that somehow all the insulation fell off of it one day, which fitted nicely into the RCBO and then somehow a croc clip attached itself to the driver and I accidentley pushed the test button and it worked, of course I threw the driver away as it was against all H & S issues, but it was handy for that one time I used it:cowboy::angel_smile:

 

[Des 56]

I used to have an old neon driver that somehow all the insulation fell off of it one day, which fitted nicely into the RCBO and then somehow a croc clip attached itself to the driver and I accidentley pushed the test button and it worked, of course I threw the driver away as it was against all H & S issues, but it was handy for that one time I used it:cowboy::angel_smile:

Its funny how these dangerous practices can become known to many people after a few years of performing,heaven forbid we should do these sort of things

 

[malcolmsanford]

Des I had so many sleepless nights over it that I had to confess to the HSE.

 

[Des 56]

HSE

Thats got to be the Heavenly Sleep Experience,confessions can lead you to it

 

[T&Earth]

Hi Malcomsanford

Thanks for your reply I unstand exactly, things like that happen to me all the time!!
Steve

 

[knasher]

Hi!
I've never really been clear on how to conduct RCBO tests at the CU. Would anyone be able to give me a quick step-by-step guide? I've searched everywhere but can't seem to find this information. Thanks

 

[IQ Electrical]

Hi!
I've never really been clear on how to conduct RCBO tests at the CU. Would anyone be able to give me a quick step-by-step guide? I've searched everywhere but can't seem to find this information. Thanks

You just have 1 probe on the line terminal of the load side of the RCBO and the other probe on the earth bar/terminal with all load disconnected.

Check out Guidance Note 3 page 56 for reference.

 

[Sickmick]

My Megga multi function tester came with a fancy big red probe with various tips that had never gotten any use as the croc clip leads did the job just fine, then these RCBOs came along and I found the big red probe ideal for getting to the live terminal nice and safely.

 

[richy3333]

My Megga multi function tester came with a fancy big red probe with various tips that had never gotten any use as the croc clip leads did the job just fine, then these RCBOs came along and I found the big red probe ideal for getting to the live terminal nice and safely.

Doh! I'd totally forgotten about those. Cheers

At my last assessment I asked my assessor if he wanted to see me working with the caps on my probes - so only 4mm tips. He asked if I considered myself competent, I said yes, he told me to get on with it then! (Names and content has been changed to protect the innocent).