How often should your fridge motor kick in?

Standard refrigerators kick on about once every half an hour. They run for 5-8 minutes and kick back off. This is the way the refrigerator cycles air as well as keeping everything cool. Now with high efficiency refrigerators the frequency of this might be less but last a bit longer. That's so not as much energy is used getting the motor running but it is focused on cooling longer. Overall the refrigerators should cost no more than 10 dollars a month to keep icy cold.