2 mcb's now dead

[b21playa]

bought a new crabtree starbreaker unit off ebay about 6months ago for the rewiring job.

as there is lots going on in the renovation, rings are being added slowly.

anyway out fo the box of mcb's(10), 2 6A ones have blew on the upstairs light circuit.

any ideas why this could be, or is this pure coincidence?

 

[securespark]

Fault on your circuit, surely?

 

[mst]

dead short my guess

 

[b21playa]

dead short my guess

wouldnt that surely just cause the mcb to trip and not damage it

any ideas on the best way to best for this?

 

[plugwash]

it could well be a dodgy clone and the MCBs in it may well be seriously lacking in quality/safety!

for example i've heared of knockof MCBs without the arc quenchers which would be far more likely to fail (hopefully off but possiblly on) in the event of a short.

finally what is your PSCC? a very high PSCC can cause breaker damage on dead shorts even to breakers that are built to the requirements of the relavent british standard.

 

[b21playa]

it could well be a dodgy clone and the MCBs in it may well be seriously lacking in quality/safety!

for example i've heared of knockof MCBs without the arc quenchers which would be far more likely to fail (hopefully off but possiblly on) in the event of a short.

finally what is your PSCC? a very high PSCC can cause breaker damage on dead shorts even to breakers that are built to the requirements of the relavent british standard.

possibily could be a clone, may just have to replace them with screwfix items which are more likelyt to be genuine.