Liebert Series 600T - Manual (Page 74)

68 Operation
System Status Messages
The system status messages indicate whether the static bypass switch is connected or disconnected, through the
manually operated Static Switch Disconnects (see Figure 9). The status messages also advise the operator when
a transfer or retransfer between the UPS system and bypass line is permitted, based on matching voltage, fre-
quency, and phase.
The following status messages may appear in the system status area.
1. Static Switch Connected. The static switch is connected (the disconnect switches are closed—ON) and is
ready provide a current path from the bypass input to the load.
2. Static Switch Disconnected. The static switch is disconnected (the disconnect switches are open—OFF) for
maintenance procedures.
3. OK to Transfer. The UPS system voltage, frequency, and phase match the bypass line. This means that a
transfer between the bypass line and the UPS system is permitted.
4. Not OK to Transfer. Either the UPS or bypass voltage, frequency, or phase is not within the specified
limits or the static bypass switch is not available. Therefore, manually initiated transfer between the bypass
line and the UPS system is not permitted. Emergency or overload transfer to bypass may still be available
provided the “static switch unable” alarm is not indicating.
Load Block Messages
Status messages in the Load block indicate how many modules are in the system, how many modules are ON
LINE, and whether the system is operating in the redundant mode.
The following status messages may appear in the load block.
1. N OF X MODULES CONNECTED. The number N is the number of UPS modules ON LINE. This means
the module output circuit breaker is closed. X is the number of UPS modules in the system (connected to this
SCC). This number is set from the System Configuration screen.
2. REDUNDANT. The capacity of the UPS modules ON LINE is sufficient to supply the critical load even if
one module is taken OFF LINE. The critical load will remain on the UPS system if one module goes OFF
LINE.
3. NON-REDUNDANT. The critical load will be transferred to bypass if one module goes OFF LINE, and
you must transfer the load to bypass in order to perform maintenance on any UPS module.
4. TIME TO OVERLOAD TRANSFER. During an overload condition, the time remaining before transfer
(in seconds) is displayed at the bottom of the load block. At each Module (MMU), the message is Time to
Overload Shutdown.