Engine 2014: Electricity

1. A preparation for transitioning from the direct liquid recovery mode to the direct vapor recovery mode
2. B preparation for transitioning from the direct vapor recovery mode to the direct liquid recovery mode
3. C preparation for a recovery unit shutdown where the next job will be to recover a different type of refrigerant
4. D preparation for a normal recovery unit shutdown where the next job will be to recover the same type of refrigerant

Tip: press A-D to answer