This system has been driving me crazy! Been tripping main breaker. When arriving system always in defrost and main breaker tripped at sub-pannel! Finally found releasing solenoid coil going to ground at termination!! Staying true too theroy will always pay off if you stay consistant! Whats the load and what is all in front of it!! Use to be on ladder diagrams you could cought on comming off of one side of the load and get too one side of line. And the other side of the load would go through your controls. Now a days they are breaking both sides!