Fan "tripping" breaker, but switch not flicking

[Paul-man]

Every few minutes, the downstairs lights were going out. Went to the CU and all breakers appeared to be in the "ON" position. However, turning the lighting breaker off, then back on again seemed to reset everything.

The MCD is a SquareD brand?

Eventually found that turning the isolator off on one of the ensuite fans stopped the tripping, but it doesn't seem right that the breaker isn't flicking. Is this common and is it a fault?

 

[RF Lighting]

Some circuit breakers trip to a mid position. Could yours be doing this?

 

[Paul-man]

It didn't look very mid positioned. I had to rely on the labels to work out which breaker to use. Incidentally, the installation was put into this house about 10 years ago and house has hardly been lived in. The CU is in the cellar.

 

[RF Lighting]

It sounds like something might be causing the lever to stick but at least the mechanism seems to still be working.

It would probably be a good idea to have the suspect breaker replaced anyway.

 

[Paul-man]

Thanks.

Will get fan sorted at the same time, not sure why that should have gone wrong.