Patent ID: 8125102

Claim:
A power supply system comprising: an AC power line; a first uninterruptible power supply (UPS) device coupled to receive input power from the AC power line, the first UPS device including control circuitry configured to couple power conversion circuitry to the AC power line upon detection that the input power is acceptable, and upon expiration of a first delay time; a second UPS device coupled to receive input power from the AC power line, the second UPS device including control circuitry configured to couple power conversion circuitry to the AC power line upon detection that the input power is acceptable, and upon expiration of a second delay time; and a controller coupled to the first UPS device and the second UPS device and configured to set the first delay time of the first UPS device to one of at least two distinct pre-programmed delay times and the second delay time of the second UPS device to one of the at least two distinct pre-programmed delay times.