Small multi-zone running off on transformer. O.K. the in series 3A breaker is cutting out. because the common is grounded on the circuit how does one go about finding a fault and what is the best way to test the circuit for high res. short of removing each load from the circuit and retesting? BTW i finally found a coil in the heating section that had abnormally high res. there has to be a faster way to do this. i took me close to 4 hours to check every load.