This is Warren from Switched on Hadyman your local electrician in the Redlands, with a helpful hint for you.
Safety switches are devices that we are supposed to have in our switch boards to help protect us against eletric shock. However, not many of us remember or even know that we need to test them regularly to make sure they are operating. The trip mechanism can seize up and not operate when it is supposed to, to save your life when something becomes faulty.
The safety switches in your switch board and lots of time will be larger than the other devices and have an extra button on the front of them. That is the test button. If you press the test button and it trips off, than that is good. If it does not trip, that is bad and a sign of a faulty safety switch and it will need to be replaced by an electrician like me.
Make sure you save things on your computer before you try testing your safety switch.