Candy dryer keeps tripping main fuse?

My dryer keeps tripping my main fuse at the board,I know it's the dryer as I've isolated it to make sure
My problem is the last time it happened it was the heater which I replaced to cure it,but looking at the heater it looks ok.
I don't really want to buy a new heater to find out its not the cause,, ps .the heater is working fine ....any ideas

Bill tomo
February 2013