Power Build series modular UPS systems are configured using hot swappable 10KVA modules. These UPS systems comply with IEC-62040 standards using double conversion technique, yet achieving an excellent overall efficiency of 96% at full load. Input power factor >= 0.99 and input current distortion < 5% even for crest factor loads at output side upto 6:1 are some salient features of this UPS. Multiple hot swappable modules of 10KVA each are connected in parallel and can be configured to operate with either a common battery set or individual set of batteries for each module. The controller module is also hot swappable and position free in a N+1 configuration. This scalable type modular UPS is available in 50KVA and 100KVA racks and can be configured for either 3-3, 3-1 or 1-1 configuration without any addition or subtraction of hardware. Parallel racks can be used for expanding the capacity more than 100KVA. The UPS is SNMP ready with communication interface for monitoring and control.