Emerson 115-600V, 115-120, 15-90KVA, 115-208 UPS operating modes, Operating mode Descriptions

Operation

8.0 OPERATION

! WARNING

Risk of electrical shock and arc flash. Can cause property damage, injury and death.

The Liebert® APM™ contains high voltages internally. Components that can only be accessed by opening the protective cover with tools cannot be serviced or replaced by the user.

Only properly trained and qualified service personnel are authorized to remove the protective covers.

The Liebert APM operates in the modes shown in Table 22. This section describes various kinds of operating procedures under each operating mode, including transfer between operating modes, UPS setting and procedures for turning on/off inverter.

Table 22 UPS operating modes

Operating mode		Descriptions
Normal mode	NORMAL	UPS powers the load
		The load power supply is provided by the static bypass. This mode can be regarded
Bypass mode	BYPASS	as a temporary transition mode between the normal mode and maintenance bypass
		mode, or a temporary abnormal operating status.
Maintenance	MAINT	UPS shuts down, the load is connects to the mains through the Liebert BDC. In this
Mode		mode the load is not protected against abnormal input utility power.

As shown in Figure 48, the AC utility source is supplied through the input breaker, and the rectifier converts the alternating current into DC power. The inverter converts the AC 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 using the Liebert BDC.

Figure 48 Single module block diagram—Single input configuration with three-breaker Liebert BDC

72