A method is provided for operating a static transfer switch to eliminate transformer inrush current in the presence of residual flux. The method includes: detecting an interrupt of electric power at an output terminal of the static transfer switch; control...

A UPS includes an input that receives first power from a utility source to power a load and receives second power from the utility source. The load is separate from the UPS. An inverter receives when in a first mode, the first and second power and when in ...

When the preferred voltage source for a static transfer switch is a UPS, there can be a brief interruption in the voltage received from the UPS while the UPS is switching from economy mode to normal mode. Operation of the static transfer switch can be impr...

An UPS system and a method of supplying power to a non-linear load are provided. The UPS system may include a bypass module (100) configured to supply a fundamental wave current to a non-linear load of the UPS system; and a power module (200) configured to...

In accordance with an aspect of the present disclosure, battery string cell data obtained by a battery monitor monitoring the battery string is transmitted to a computer by the battery monitor. The computer has a display coupled to it. The computer display...

A method and apparatus are disclosed for improving the disturbance pass through characteristics of a line interactive uninterruptible power supply ("UPS"). One disclosed technique uses a naturally commutated fast utility disconnect switch, wherein the swit...

A UPS device (10) of universal application provides a pair of backfeed relays (represented at block 116), which are mandated by certain countries outside the United States, controlled (as represented by line 142) by an overall control circuit (represented ...