Crankcase heaters have an important job: they keep refrigerant from migrating to the compressor during the off cycle. As such, we need to take a thoughtful approach to wiring them depending on what we have available, whether that's a single-pole contactor, a double-pole contactor, or a White-Rodgers SureSwitch. Our latest video covers some tips for crankcase heaters and refrigerant charging. You can watch it on our website at: https://buff.ly/lfaBshd | HVAC School