Liebert GXTTM user manual Rectifier/Power Factor Correction Pfc Circuit, Inverter, Battery Charger

RECTIFIER/POWER FACTOR CORRECTION (PFC) CIRCUIT

In normal operation, the rectifier/power factor correction (PFC) circuit converts mains AC power to regulated DC power for use by the inverter, while ensuring that the wave shape of the input current used by the UPS is near ideal. Extracting this sinewave input current achieves two objectives: the mains power is used as efficiently as possible by the UPS, and the amount of distortion reflected on the mains is reduced. This results in cleaner power being available to other devices in the building not being protected by the UPStation GXT.

INVERTER

In normal operation, the inverter utilises the DC output of the power factor correction circuit and “inverts” it into precise, regulated sinewave AC power. Upon a mains power failure, the inverter receives its required energy from the battery through the rectifier / PFC. In both modes of the operation, the UPS inverter is on-line and continuously generating clean, precise, regulated AC output power.

BATTERY CHARGER

The battery charger utilises energy from the Rectifier / PFC and precisely regulates it to continuously “float” charge the battery system. The battery system charges whenever the UPStation GXT is connected to mains power.

BATTERY

The UPStation GXT employs valve regulated, non-spillable, lead acid batteries. At typical room temperatures and with the UPS float charging, the battery system will last many years. Optional external battery cabinets are available to provide extended run times.

STATIC BYPASS

The UPStation GXT provides an alternate path for mains power to the connected load, in the unlikely event of a UPS malfunction. Should the UPS have an overload, over temperature, or UPS failure condition, the UPS automatically transfers the connected load to BYPASS providing the bypass voltage is within specification. BYPASS operation is indicated by an alarm and an illuminated BYPASS LED (other LED’s may be illuminated to indicate the diagnosed problem). To manually transfer the connected load from the inverter to BYPASS power, press the output OFF button once.

NOTE: The BYPASS power path does NOT protect the connected equipment from disturbances on the mains supply and its range of operation is limited to +/- 15% of the nominal input supply voltage.

AUTO RE-START

Upon restoration of the mains AC power after a mains power outage and complete battery discharge, the UPS will automatically restart and supply power to the critical load and the battery charger automatically recharges the battery.

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