RCBO Blew Up

[LewisM]

Fireworks may have been an exaggeration however it was more a sustained arcing and smoke until the Power was removed, I have spoken to Hager who said to simply test trip times of other RCBOs and via the test button

 

[pc1966]

Hmm, odd. It sounds like the FE causing trouble but as far as I understood them they simply trip the RCBO if the neutral goes open.

 

[telectrix]

ramp test it as well.

 

[loz2754]

This would not have happened if the full sequence of initial inspection and testing had been followed, even (perhaps especially) with a temporary supply.

 

[LewisM]

This would not have happened if the full sequence of initial inspection and testing had been followed, even (perhaps especially) with a temporary supply.

Yes you are correct it's the usual case of rushing to get things done, full testing is to be undertaken this was to see if there was enough light or if more were needed

 

[Lucien Nunes]

This would not have happened if the full sequence of initial inspection and testing had been followed

But at this point the question is what caused the RCBO failure, as even though there was a procedural deviation leading to a reverse polarity connection, I agree that this alone shouldn't make it go bang. It might have been defective and gone bang anyway with a normal supply, or there might be a subtle shortcoming in the design that is not generally known.

Can you break open the RCBO so we can study the failure mode?

 

[suffolkspark]

Would also be interested if you can drill it open and get some pics

 

[LewisM]

Will do on Monday

 

[LewisM]

Got nice and hot then

 

[Lucien Nunes]

Hmm. Are you sure that was running from a 13A extension lead?
The initial failure led to a more extensive power arc that will have covered much of the evidence in soot. For forensic purposes I am sure it would yield information given enough time and care to extract.

It would be interesting to know what Hager technical say. If it were mine I would contact them, state that an RCBO failed on a reverse-polarity supply and see if they can can add anything. They might even be interested to have the failed device back for inspection.