Emerson 540VDC manual Charge Mode, Ready Mode, Voltage ≥ Vcharge

System Overview

5.3.4CHARGE Mode

To charge the Liebert FS, the Liebert FS will draw power from the UPS DC bus to accelerate the fly- wheel (as long as the UPS DC bus voltage is higher than Vcharge). In this mode, the Liebert FS State of Charge (SOC) will progressively increase from 0% to 100%.

Figure 48 CHARGE mode diagram
State of Charge < 0	State of Charge > 0

0%

Note: UPS DC Bus Voltage ≥ Vcharge

991 .00% 5%

The Liebert FS will be in CHARGE mode as long as:

•Liebert FS’s SOC is between 0% and 100% and

•UPS DC Bus Voltage ≥ Vcharge.

NOTE

While in CHARGE mode, the Liebert FS will be capable of supporting the UPS DC bus.

5.3.5READY Mode

When the SOC reaches 100%, the unit will automatically transition into the READY mode. This is the mode in which the Liebert FS will spend most of its operating time. In this mode, the Liebert FS maintains its State Of Charge greater than 99.5%. The Liebert FS’s SOC will be allowed to drift down to SOC = 99.5%, at which point it will transition back into CHARGE mode and charge back up to READY mode and SOC = 100%. During normal operation, the Liebert FS will continue to automati- cally transition between the READY and CHARGE modes to maintain a SOC between 99.5 and 100% until either a DISCHARGE or SHUTDOWN is initiated.

Figure 49 READY mode diagram

State of Charge < 0	State of Charge > 0	Note: UPS DC Bus
		Voltage ≥ Vcharge

0%

991 .00% 5%

The Liebert FS will be in READY mode as long as:

•Liebert FS’s SOC is between 99.5% and 100% and

•UPS DC Bus Voltage ≥ Vcharge.

NOTE

While in READY mode—just as in CHARGE mode—the Liebert FS will be capable of supporting the UPS DC bus.

47	DISCONTINUED
	PRODUCT