5.1.1 Sleep Mode
While in the sleep mode of operation, the UPS’s display is inactive and no voltage is present at the output. The UPS enters the sleep mode following a 5 minute interval when no commands are given while in the standby mode (see following section). Following a 5 minute interval, the UPS will enter the sleep mode from the on- battery mode when shut down due to battery capacity exhaustion or overload. This is done to conserve battery capacity. To "awaken" the UPS to make it receptive to commands, any one of the front panel pushbuttons may be pressed.
Some versions of PowerChute plus allow the user to put the UPS to sleep and awaken it after a user set interval.
5.1.2 Standby mode
While in the standby mode of operation, the UPS’s display and control interface is active, but no voltage is present at the output. The UPS enters the standby mode of operation when first "awakened" from the sleep mode. The UPS is awakened when any one of the three front panel pushbuttons is pressed.
5.1.3 On-line mode
Once commanded to power the loads, the UPS is normally in the on-line mode of operation. While in this mode, the UPS delivers power to the loads derived from the utility and maintains proper battery charge. In this mode, the UPS regulates the output voltage to within a narrow band and serves to isolate the load from surges and electrical noise brought by the service wiring. A multilevel transformer tap changing circuit provides this regulation and isolation while maintaining extremely high efficiency. In response to the need to adjust the load voltage, the UPS temporarily operates the load from power derived from the battery while an appropriate transformer tap change is made. Remote on-battery signalling is disabled when this action is accomplished.
The UPS’s display indicates the percent of rated load applied at the output when operating on-line.
5.1.4 On-battery mode
When in the on-battery mode of operation, the UPS provides power to the load derived by the UPS’s inverter from the Battery Packs. The voltage waveshape delivered during on-battery operation is a low distortion sine wave. While on- battery, the UPS regulates the output voltage and frequency to within a narrow band. The UPS operates in the on-battery mode during the user defeatable start-up or scheduled battery tests. The UPS operates on-battery when the line voltage or frequency has fallen outside the limits given in the Specifications section of this manual or has become extremely distorted by, for example, noisy adjacent service branch loads or an overburdened fuel generator source.
Operation on-battery is limited in duration and is dependent upon available battery capacity and load. Local users are alerted to this mode of operation by visual and audible indicators. When on-battery, the UPS displays available run time and emits a sequence of four "beeps" every 30 seconds. During an extended utility failure, the battery capacity will eventually become too low to support the load and the UPS will shut down. The UPS will alert the user to a low battery condition 2, 5, 7, or 10 minutes prior to shut down, depending upon the user setting. The UPS will emit a "beep" once every second to warn local users of the low battery condition. The UPS alerts remote users to on-battery operation and low battery conditions via serial communications or simple signalling from the computer interface port.
