The SagFighter™ active voltage conditioner continuously monitors the input voltage waveform for any deviation from a balanced, three-phase voltage. Upon sensing a deviation, the SagFighter engages an inverter circuit to apply an injection voltage to the primary windings of the series-connected transformer. The injection voltage is synthesized with a magnitude, shape, and phase angle so that when it is added in series with the incoming voltage, a balanced, three-phase voltage results. When normal, three-phase incoming voltage is detected at the SagFighter input, the inverter circuit is disengaged and the unit returns to monitoring mode.
The SagFighter is thermally ranged to provide continuous correction for a voltage sag, although this is not normally required.
The SagFighter uses natural convection cooling and has no fans or other moving parts. Larger units may include heat-sink fans that operate only when the unit is correcting a sag event. An automatic electronic failsafe bypass is incorporated into the standard design so the SagFighter maintains power to the load if a unit malfunctions.
The SagFighter automatically corrects voltage sags with no operator or programming required. The unit display provides unit status and historical information on sag correction events. Alarm contacts are also provided to permit remote indication of SagFighter status.
SagFighter installation is simple. The unit arrives completely assembled and requires no programming, testing, measuring or setting of switches. It is designed to install much like a dry-type transformer: simply place the unit and make input and output wiring connections. The SagFighter typically has no maintenance schedule other than routine inspection and cleaning.