Originally posted by: sparkingchip
I had a knee trembling moment yesterday as my legs wanted to turn on their heels and run.
Down in the cellar of a HMO I needed to isolate the cooker circuit and the thought went through my head "I wonder when the RCD test buttons were pressed?"
I pressed the RCD without incident then moved to the first of four RCBOs.
I pressed the RCBO test button and it buzzed, then there was a bang, smoke and the smell of charring plastic followed by more buzzing another bang more smoke and a even stronger smell of burning plastic.
This is it I thought as I threw the main switch, I'm actually going to see a plastic consumer unit go up in flames in front of me whilst I'm in a dark windowless cellar by myself, I retreated to the bottom of the stairs ready to sprint as best I can to the van and back to get my dry powder extinguisher.
I waited a short time and as nothing erupted I then removed the RCBO from the CU to find it had contained the arc.
I put the whole incident down to lack a lack of regular RCD testing with no one doing it in the last two and a half years since I last did it.
It does make the old knees tremble though!
Andy
Hello Andy,
I had a brand new Newlec out of the box R.C.B.O. do exactly what yours did. It must have been the test resistor overheating and blowing up as the device did not open its contacts. I will now only connect R.C.D.s and R.C.B.O.s in series, (different makes) especially on TT systems as I no longer trust just one device to operate effectively.
It is VERY worrying. More of China's best no doubt.
Z.