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4300 Series Installation and Operation Manual
12.3 Operator Controls
Bypass/On-Line Switch
Switches the UPS between On-Line and Bypass modes.
Display Reset Switch
Allows the display to be rebooted without powering down the UPS. The display can be reset by pressing
the Reset Switch with a thin probe, such as a paper clip.
EPO (Emergency Power Off) Function
These units are equipped with a front panel mounted EPO switch.
This safety feature enables quick shutdown of the UPS AC output and battery circuits.
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 is in the AC Input Mode, Battery Backup Mode, or the
Bypass Mode. See ‘EMERGENCY OFF’ screen.
The following figure shows the UPS condition after application of the EPO switch. Use the Start-up
Procedure for restarting the unit.
FIGURE 12-2 - EFFECT OF EPO ACTIVATION
Contactor
AC/DC
Converter
DC/AC
Inverter
4300 UPS
Bypass Thyristor
MCCB
AC Input
3Φ 4W
AC Output
3Φ 4W
Input
Contactor
Output
Contactor
DC/DC
Converter
Ground
Wire
Fuse
Fuse
SYNC
Fuse
TRIPPED
OFF
OFF
OFF
