Operating Instructions

After the EPO button is pressed, if the input utility is removed, the UPS will shut down completely. When input utility is returned, if the Bypass input circuit breaker (CB2) and UPS output circuit breaker (CB5) are closed, the UPS will start up on Bypass. There will be power at the output terminals of the UPS.

! WARNING

Risk of electrical shock. Can cause injury and death.

If the internal maintenance bypass circuit breaker (CB3) is closed and input utility is present, there will be power at the output terminals of the UPS.

11.10 Battery Protection

11.10.1Battery Undervoltage Pre-Warning

Before the end of discharge, the Liebert® NXdisplays a Low Battery pre-warning. After this pre- warning, the battery has the capacity for 5 minutes discharging with full load (default time). The Liebert NX can be user-configured to display this warning from 3 to 60 minutes before end-of- discharge.

11.10.2Battery End-of-Discharge (EOD) Protection

If the battery voltage is lower than the end-of-discharge voltage, the battery converter will be shut down.

11.11 Multi-Module System Procedures

11.11.1Isolating One Module in a Multi-Module System

1.Turn Off the inverter.

2.Open External Output CB4 in Parallel Cabinet (see Figure 67).

The UPS enters Isolation Status automatically, parallel signaling and communication become masked and output becomes inhibited.

3.Power Off the unit for maintenance.

4.Power On the unit.

5.Unit enters Test Mode by configuration software setting.

6.Diagnosis or testing.

7.The UPS exits Test Mode by configuration software setting. Output becomes inhibited because of Isolation Status.

8.Return all switches to the Normal position.

9.Close External Output CB4 in Parallel Cabinet (see Figure 67).

The UPS exits Isolation Status automatically, parallel signaling and communication recovers, output becomes enabled but interlocking works now.

10.Turn On inverter and join the parallel system.

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Emerson 40-200KVA user manual Battery Protection, Multi-Module System Procedures, 11.10.1Battery Undervoltage Pre-Warning