10
Figure 1-5 Battery Mode operation diagram
Note: With the function of “Battery Cold Start”, the UPS could start without utility. See more detail
in section5.1.2.
1.2.2.3 Bypass Mode
If the overload capacity of the inverter 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. The
Bypass mode structure is shown in Fig.1-6.
Figure 1-6 Bypass mode operation diagram
