The need for continuous power supply and its reliability has increased rapidly over the years, especially in all those areas where uninterrupted power supply is a must. Modern systems are power dependent. Their complexity has increased as continuous information and communications are needed to control automated process, be in industries, commercial complexes, hospitals, hotels or even modern residences.

The need, as such, for independent stand by power system has therefore increased manifold. The power distribution, control, monitoring and protection of stand by power system needs to be integrated. Stand by generator systems, for example, are required to cater to :-

Sensitive Loads are supplied by UPS systems. The period of      non-availability of power, before the stand by supply takes      over, is bridged by battery banks. Typical loads are computers,      hospital equipments, micro processor controlled industrial      machines etc.

Critical Loads mostly involve stand by generator systems      which supply power to lighting systems, air conditioning,      elevators etc in Airports, Hotels and commercial complexes.