i was calling local suppliers to get a 2 wire defrost termination switch the kind that clips onto the copper not the one that has 2 screws and goes up against the sheet metal. having trouble finding one. went to one reputable supplier got back to the job and realized i was given a heater limit switch. to make sure i put it in ice and it would close then put it under warm water it will then open, so i returned and picked up this 3 wire one by supco in the pix. but to me it looks like a limit switch/ fan delay switch. the one in the pix. from my understanding and correct me if im wrong. the defrost termination must open on a temp decrease and close on a temp. rise to terminate the defrost cycle via x terminal..... any questions and answers welcome.
im thinking about using the fan delay part terminals #1  as termination in the switch shown in the pix. the one with the arrow is the one i have.