Grounding of standby and emergency power systems

Power continuity is essential in many industrial and commercial installations where a trip out due to a ground fault can have serious economic or operational consequences. An arcing phase to ground fault can pose a flash hazard to the maintenance worker close to the fault and can totally destroy the equipment. Consequential down time adds to the economic loss. Four typical grounding methods for standby generators and emergency power systems are examined for these factors and the paper concludes, based in addition on a real study case, that high resistance grounding provides the best power continuity, and the best protection against arcing ground fault damage in low voltage distribution systems (up to 1000 V) and improves reliability and availability of standby and emergency power systems.