Vertiv Liebert EXM2 - Operation Procedures for Parallel System; Startup Procedures in Normal Mode

8.3 Operation Procedures for Parallel System
Only one step is carried on for once, and only after finishing this operation step of each UPS module, the next step can be
carried on.
8.3.1 Startup Procedures in Normal Mode
These procedures are applicable to start the UPS under total power-down state, which means the UPS or the maintenance
bypass switch has not supplied the load before. Make sure UPS has been completely installed and commissioned by the
engineer, and external power supply switch has been turned off.
N O T E: T hese procedures result in m ains voltage b eing applied to the U PS output term inals.
N O T E: If any load eq uipm ent is connected to the U PS output terminals, check w ith the u ser that it is
safe to apply pow er. If the load is not read y to receive pow er, disconnect the dow nstream load
switch, and stick a warnin g label on the connection point of the load.
Use the following procedures to turn on the UPS from a fully powered down condition.
1. Confirm that the total external maintenance bypass switches are disconnected. Open the front door of each UPS
in turn, ensure that the internal maintenance bypass switch Q3 is disconnected, while the input cables and
copper bars are reliably connected, and the parallel cables are firmly connected.
W A RN IN G! In parallel UPS co nfiguration, all operations related to disconnection or connection
of the m aintenance bypass sw itch shall be executed w ith in three seconds to avoid overload
situations & dam age to the m aintenance bypass switch.
2. Close the external input supply switches .
3. Close the output switch Q5, bypass input switch Q2, rectifier input switch Q1, and all external output isolating
switches (if any) of each UPS in turn.
At the moment, the system is powered on, and the startup screen pops up.
About 25 seconds later, confirm that the TOUCHSCREEN shows the rectifier power supply and the bypass power supply are
normal; if not, check whether the switches Q1 and Q2 are closed. Then the rectifier starts up, about 30 seconds after the
rectifier enters normal operation, the bypass static switch is closed.
4. When the rectifier start process is finished and the rectifier indicator goes solid green, close the external BCB.
5. For each UPS, manually turn on the inverter. When the inverter starts up, the whole UPS system will power the
load.
8 Parallel System and LBS System
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Vertiv™ Liebert® EXM2 UPS User Manual