SNR UPS-ONRT-200-25CMX33 [11/69] Bypass mode

Figure 2- 4 UPS conceptual diagram in Battery mode

Note

With the function of Battery cold start, the UPS may start without utility.

2.4.3. 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. As Figure 2- 5 shows。

Figure 2- 5 UPS conceptual diagram in Bypass Mode

2.4.4. 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. As Figure 2- 6 shows

。