Fridge/freezer trips my circuit breaker

Question

I have a fridge with top freezer. It is a frost free and keeps tripping my circuit breaker. It is approximately 15 years old but I only got it recently. The first day it tripped my breaker after about 6 hours. I then had it turned off over night and it worked for two days without a problem. It has again begun tripping my breaker. What is it? and how can it be fixed?