Having to work off memory on this on so if i am wrong i am sure someone will correct me

Push and hold the set key, after 5 seconds it take you into the set up menu, first one being CP
use up and down to get to the defrost menu, push set, scroll through, defrost termination temp should be DLI, Defrost interval time (Time between defrosts) is DTI
Defrost Endurance time is DET

Hope this helps
Regards

Raymond