Emerson 40-200KVA General Description, Single module block diagram dual input configuration

Operation

9.0OPERATION

9.1General Description

Liebert’s NX provides continuous, high-quality AC power to your business-critical equipment, such as telecommunications and data processing equipment. The Liebert® NX™ UPS supplies power that is free of the disturbances and variations in voltage and frequency common to utility power, which is subject to brownouts, blackouts, surges and sags.

The Liebert NX utilizes the latest in high-frequency, double-conversion pulse width modulation technology and fully digital controls to enhance its reliability and increase the ease of use. Specifically, the Liebert NX 480V utilizes soft-switching technology to greatly enhance efficiency.

As shown in Figure 51, the AC utility source is input at CB1 and the rectifier converts the AC utility into DC power. The inverter converts that DC power from the utility—or DC power from the batteries—into AC power for the load. The batteries power the load through the inverter in the event of a power failure. The utility source can also power the load through the static bypass.

If maintenance or repair of the UPS is necessary, the load can be switched without interruption in service to the maintenance bypass.

Figure 51 Single module block diagram (dual input configuration)

3-Phase	Internal Maintenance Bypass
3W + Gnd

3-Phase	Static Bypass
3W + Gnd

AC Input	Rectifier	Inverter
		Converter

UPS Cabinet

2W + Gnd

3-Phase 3W + Gnd

AC Output

Battery Cabinet

77