Guys,
If its a 10A BS EN 60898 MCB Type B then it has an instanteneous trip current of 3 to 5 times In (nominal value). Type C is 5 to 10 times In
So a 10A takes between 30-50 amps to trip straight away
A quick check of fig 3.4 (bullrush chart for 60898's) in the 17th edition tells me that at 15A a 10A breaker would take 10,000 seconds to blow, any less current and it would sit there happily forever
at a trip time of 5 minutes you've got about 18 amps flowing
Now isnt that the kind of simple, informative and accurate answer that you guys miss........
Jesus, this place is like a morgue........
regards
the ghost of a departed friend.....................