Fridge freezer compresor keeps clicking on and off?

Hello
When i recently defrosted my freezer and went to refreeze it the compresor kept clicking on and off -- 5mins on and 5 mins off. I understand it would do this ifdown to tempreture but it did this after defrosting and took a long time to refreeze. Is this normal or have i a fault.
Please help as i am a very nice man.
Thanks Dave