Chapter 6 Operating Instructions
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MUST400_User manual_EN_REV02 User Manual
6.4 Procedure for Completely Powering Down a UPS
If you need to power down the UPS completely, follow the procedures as follow:
Press EPO button on the right side of operation panel
Open external battery breaker and internal battery breaker
Open mains input breaker (Q1) and output breaker (Q3)
If you need to isolate the UPS from the AC power supply, you should open the external input power supply
isolation first (if the rectifier and bypass use different power supply, you need to open these two input isolation
respectively).
6.5 EPO Procedure
The EPO button is designed to switch off the UPS in emergency conditions (e.g., fire, flood, etc.).To achieve
this, just press the EPO button, and the system will turn off the rectifier, inverter and stop powering the load
immediately (including the inverter and bypass), and the battery stops charging or discharging.
If the input mains is present, the UPS control circuit will remain active; however, the output will be turned off.
To completely isolate the UPS, you need to open the mains input breaker and battery breaker.
6.6 Auto Start
Commonly, the UPS rack is start up on static bypass. When the mains power fails, the UPS draws power from
the battery system to supply the load until the battery voltage reaches the end of discharge (EOD) voltage,
and the UPS transfer to bypass line if present otherwise the UPS will shut down.
The UPS will automatically restart and enable output power:
After the mains power is restored
If the Auto Recovery after EOD Enabling feature is enabled
6.7 UPS Reset Procedure
After using EPO to shut down the UPS, operates as following to restore UPS:
Shutdown UPS completely
Start UPS as section 6.2.1
After the UPS is shutdown due to inverter over temperature, or overload, or too many switching times, UPS
will reset the fault automatically when fault is cleared.
Note
The rectifier will be turned on automatically when the over temperature fault disappears after the
disappearance of over temperature signals.
After pressing the EPO button, if the UPS mains input has been disconnected, the UPS is completely powered
down. When the mains input is restored, the EPO condition will be cleared and the UPS system will enable
static bypass mode to restore the output.
Warning
If the maintenance bypass breaker is put to ON and the UPS has mains input, then the UPS output is
energized.
警告
危 险
警告
危 险
