Liebert NX UPS System user manual Isolating One Module in a Multi-Module System

Operating Procedures

6.12Isolating One Module in a Multi-Module System

NOTE

The Multi-Module system must have at least one UPS module redundant in the system and have an external output breaker installed with interlocking cables connected to the UPS module. The inverter firmware in each UPS in the system must be I140 or greater.

1. With all UPS modules in the system in Normal mode, open the external output isolator.

NOTE

Opening the external output isolator under these condtions puts the UPS module into Standby mode. This is indicated by a flashing inverter LED and the message “Check UPS output.”

An “Inverter asynchronous” alarm is also normal. The remaining UPS modules will remain on line and “Parallel comm fail” will annunciate.

2.Press the UPS EPO to isolate the batteries.

3.Open the UPS door to gain access to the main power switches SW1 and CB1.

4.Turn the rotary switch (SW1) to the Bypass position then continue to rotate to Test.

NOTE

With the UPS external output breaker open and auxiliary switches closed the UPS control will enable the UPS switch to be rotated through “Bypass” without initiating the remaining on line UPS modules to transfer to Bypass.

5. Open rectifier input breaker CB1.

! WARNING

Hazardous Battery Voltage

No operator serviceable parts are located behind covers that require a tool for their removal. Only qualified service personnel are authorised to remove such covers.

The UPS battery and connecting terminals remains energized at hazardous voltage levels at all times. The battery is located behind protective covers that require a tool for their removal: inside the UPS cabinet, inside a free-standing battery cabinet or on open racks inside a dedicated battery room that may be locked.

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