During the initial cooling down of a box temperature in a refrigeration system, which of the devices listed is used to prevent excessive gas pressure at the compressor suction for the purpose of prevention of overloading of the compressor driver?

Correct Answer: Option C — Crankcase pressure regulator

A crankcase pressure regulator, or back-pressure valve, limits suction pressure during high-load pull-down periods. This prevents excessive refrigerant mass flow from overloading the compressor motor and tripping thermal overloads.