He charges R450per hour which I do not have a problem with. Plus he added R450 as a call-out fee. He only worked during the day, so I don't know where the after hours call-out fee comes from.
He charged R580 to replace the breaker, which I suppose is the cost of the item replaced.
Is 4 hours to trace and find a fault reasonable?

The way I see it is that you do not pay a carpenter for hitting in a nail, but you pay him for knowing where to place the nail.