I've always pondered whether cramming the RCD/GFI circuitry into a breaker designed to break up to 10,000A of fault current was a compromise. It turns out it does open up the possibility of an internal flashover.
My guess for the fault scenario that caused this is that the switching contacts welded shut allowing current to continue flowing, the electronic module tried to trip the welded mechanism, and then burned out initiating an arc that allowed the live to flash over to the neutral.
John Ward featured a similar breaker failure. His video is here:-
https://www.youtube.com/watch?v=TRUBlZCNo8U
I'd suggest resetting these breakers with extreme caution if you believe there to have been a major fault condition that may still be present. The presence of the Live and Neutral connections in the same enclosure raises the risk of plasma/explosion hazards.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
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This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
My guess for the fault scenario that caused this is that the switching contacts welded shut allowing current to continue flowing, the electronic module tried to trip the welded mechanism, and then burned out initiating an arc that allowed the live to flash over to the neutral.
John Ward featured a similar breaker failure. His video is here:-
https://www.youtube.com/watch?v=TRUBlZCNo8U
I'd suggest resetting these breakers with extreme caution if you believe there to have been a major fault condition that may still be present. The presence of the Live and Neutral connections in the same enclosure raises the risk of plasma/explosion hazards.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
why RCDs in England have this weird extension going on, while in Europe, Lithuania where I live they are the normal sized without any extensions?
This is an expensive little device, I had to think few times to have more than one installed in my house but safety is the most important aspect to be considered here.
Very interesting that the first sign of a problem was nuisance tripping. I became involved with an installation where the main board was loaded with breakers of the same brand. It started with one nuisance tripping so I replaced it. After the third failure within two weeks the whole lot disappeared into the round filing cabinet. I replaced them all with Clipsal breakers and no problems since. Luckily none of the breakers in this installation moved on to the pyrotechnic stage. I have been using Clipsal breakers for a long time now and I have never had a problem.
I love your work Clive, thank you for the post mortem.
Reminds me of Vicki road south side 😁
Been held closed so many times. Indian restaurant????? Lol
The problem with circuit breakers is folk switch them back on without 1st switching everything down stream off, reducing the load from the contacts.
That switch had been repeatedly reset over time resulting in wearing the contacts out.
Wonder if they are now wearing the new breaker out instead of tracing the earth leakage fault?🤔 🤠
love the smell of burnt breakers early in the morning and terrified late at night !
The welded contacts remind me of a time our old (1999) 10kVA UPS ran until all three battery cabinets were depleted. Once we got the mains back up, we had to run on bypass until the vendor could come out to give it the old crowbar and hammer fix.
European CBs are so cheesy compared to american spec ones, especially bolt in commerical ones
I would suggest the power lines were subject to a lightning strike and the resultant surge has destroyed the breaker.
Burned plastic is not good to touch with bare hands.
Drill my hand . Done it before !
Countries that use miniature breakers fore primary branch circuit protection are foolish not to mention 240 volts to ground. Im a licensed electrician in the USA hear you MUST use a MOLDED CASE BREAKER for primary branch circuit protection. Miniature breakers can only be used for supplementary protection after the branch breaker even at 120 volts to ground.
Very scary to use those breaker failed to trip
What brand of breaker is this? For what panel? I have never seen a breaker like this.
👍👍😊
At least it didn't burn, the proper material was used in the case ..