4200FA XT 80kVA Installation and Operation Manual
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6.6
EPO (Emergency Power Off) Function
The 4200FA UPS system is equipped with terminals for receiving an emergency power-off
(EPO) closed contact switch command from two locations: (1) a remote location (see Section
4.2 Terminal Block Details) and (2) from a front panel mounted EPO switch (see Section 6.5
Front Panel Layout).
This safety feature enables quick shutdown of the UPS AC output and battery circuits.
Typically the emergency power off switch is installed in a central location that is easily
accessible to personnel concerned with the operation of the UPS unit and the equipment
connected to it. The EPO function is initiated by pressing the switch to the closed Shutdown
position. The effect of using the EPO switch is the same whether the UPS unit is in the AC
input mode (see Section 6.1.1), battery backup mode (see Section 6.1.3), or the circuit bypass
mode (see Section 6.1.2). See EMERGENCY OFF screen in Section 6.12 Shutdown
Procedure. The following figure shows the UPS condition after application of the EPO switch.
Use the Start-up Procedure (see Section 6.11) for restarting the unit.
6.7
Audible Alarm Functions
While in the battery backup mode, during a fault, during a low battery condition, or if the
system is in an overload condition, an audible alarm will sound. The following table shows the
audible alarm pattern for each condition. Time intervals are shown in seconds. The audible
alarm can be stopped by pressing the BUZZ STOP key (see Section 6.5 Front Panel Layout).
Condition
Audible pattern
UPS in Battery Backup Mode
(Battery Voltage 100-90%)
UPS Low Battery
(Battery Voltage < 90%)
Overload
Fault
1 S
7 S
1 S
1 S
.5 S
.5 S
.5 S
.5 S
Converter
Inverter
Static
Bypass
Charger/
Chopper
Isolating
XFMR
External
Batteries
Output
Power
Input
Power
MCCB
Power Flow
TRIPPED
OFF
OFF
OFF
OFF
