Chapter 1 Product Introduction
3
SM 180-600 KMFX User Manual
Rectifier
AC/DC
Main
Static Bypass
Manual Bypass
Inverter
DC/AC
Discharge
DC/DC
Output
Battery
Bypass
Fig.1-5 Battery mode operation diagram
1.3.3 Bypass Mode
If the inverter overload capacity is exceeded under Normal mode, or if the inverter
becomes unavailable for any reason, the static transfer switch will perform a transfer of
the load from the inverter to the bypass source, with no interruption in power to the critical
AC load. Should the inverter be asynchronous with the bypass, the static switch will
perform a transfer of the load from the inverter to the bypass with power interruption to the
load. This is to avoid large cross currents due to the paralleling of unsynchronized AC
sources. This interruption is programmable but typically set to be less than 3/4 of an
electrical cycle, e.g., less than 15ms (50Hz) or less than 12.5ms (60Hz). The action of
transfer/re-transfer can also be done by the command through monitor.
Rectifier
AC/DC
Main
Static Bypass
Manual Bypass
Inverter
DC/AC
Charger
DC/DC
Output
Battery
Bypass
Fig.1-6 Bypass mode operation diagram
1.3.4 Maintenance Mode (Manual Bypass)
A manual bypass switch is available to ensure continuity of supply to the critical load
when the UPS becomes unavailable e.g. during a maintenance procedure. (See Fig.1-7).
