The "Hitec" make Diesel Rotary UPS (DRUPS) Power Module comes with skid-mount single shaft assembly of rotating machines - basically comprising Diesel Engine, Free-Wheel Clutch, Induction Coupling and Generator.

Under normal operating conditions the mains power feeds the DRUPS System and customer's Critical Load via specially designed choke by Hitec. The DRUPS system stabilises the mains voltage within the acceptable tolerances and improves the power factor of the system. The DRUPS System runs continuously synchronised with the mains.

When the mains power supply to the DRUPS System fails or goes out of tolerances, the DRUPS System continues to supply full output load without interruption. Simultaneously the incoming mains get disconnected from the system. The rotary energy storage device (induction coupling) ensures continuity of power during the diesel engine start-up period. After reaching full speed, the diesel engine engages to the induction coupling and generator via free wheel clutch and works as normal standby diesel generating set. The load never knows the power transfer from mains to DG set.