3 pole breaker query

Robert M. · Jun 16, 2020

I know it needs to be replaced, but what actually causes a 3 pole breaker to suddenly stop being able to stay in the on position please, and that's even without it connected to anything (i.e. the switch mechanism makes the correct sounding click when push up, but immediately springs down)????

pc1966 · Jun 16, 2020

Could be many things, but usually it is just the trip-over mechanism has had a fault (more likely so on older ones that have hardly ever been cycled during test, etc). However, if it has been tripping regularly and reset on to an overload it might be thermally related damage.

How old is it, and can you easily get a replacement?

Robert M. · Jun 16, 2020

pc1966 said:
Could be many things, but usually it is just the trip-over mechanism has had a fault (more likely so on older ones that have hardly ever been cycled during test, etc). However, if it has been tripping regularly and reset on to an overload it might be thermally related damage.

How old is it, and can you easily get a replacement?

Thank you for very quick reply......it's Square D QOE, so unlikely I'll get a new one (unless old stock), so I'm probably looking at getting a used one which could of course go the same way as the old one very soon (a new board is not really an option)!!

dodger421 · Jun 17, 2020

Robert M. said:
Thank you for very quick reply......it's Square D QOE, so unlikely I'll get a new one (unless old stock), so I'm probably looking at getting a used one which could of course go the same way as the old one very soon (a new board is not really an option)!!

You’d be surprised. I had something similar at work a couple of months ago, we needed to replace a 16A QOE breaker with a 20A RCBO for a socket circuit. Schneider manufacture compatible MCB’s and RCBO’s, the QOvs range.

I ended up calling the account manager bloke at our local YESS Electrical with the part number from Schneider and he was able to source one for us. Wasn’t cheap, about £170 I think including next day delivery. Got us out of a hole though and might hopefully help you too.

Here’s a link to a 20A 3-pole MCB, Schneider do have the full range there.