A thermal management system for an enclosure containing electrical components includes a cooling unit for controlling temperature inside the enclosure and a controller for the cooling unit, the controller being configured so that it can receive a three-phase power input signal and distribute power and control connected components using the three-phase signal. The controller can protect the compressor in critical scenarios such as thermal overload and overcurrent. The controller can output various faults such as missing phase alarm, imbalance phase alarm, overcurrent alarm, thermal overload alarm, door open alarm, and temperature and pressure alarms. An auto phase sequence correction controls the phase relay, accepting 3 phase 480 VAC power input from facility power terminal, supplying 3 phase power to the compressor and motor impellers, 12V DC power to a display unit, and 24V DC power to a remote access control module.