Operator`s manual
Powerware Plus 18 Operator'sManual(LTM-1336B)9
Bypass Mode
In the Bypass mode, the UPS transfers the critical load directly to the filtered utility
power, provided the bypass source is available. The transfer occurs due to one of the
following conditions:
Load current is between 106Ć124% of rating for 10 minutes, 125Ć149% for 30
seconds, or >150% for 10 cycles.
UPS internal temperature exceeds safe operating range.
UPS output falls out of the specified voltage limits.
Output real power exceeds specified limits.
Load current inrush (surge) exceeds peak current capability.
When the unit is in Normal mode and automatically transfers to Bypass due to an
output current overload condition, the UPS attempts to return to Normal mode. After an
output power overload or any other abnormal condition, return to Normal mode must
be done manually (system startup). The UPS remains in Bypass mode if three
autoĆstart attempts fail within a 10Ćminute period.
To switch to Bypass (with Bypass Configuration switch enabled), hold the UPS Off
button for three seconds. The Normal indicator goes off and the Bypass indicator
illuminates.
If the alarm sounds when the UPS Off button is pressed, then Bypass is
not available. If the UPS Off button is pressed for three seconds with Bypass not
available, the UPS enters Load PowerĆOff Mode.
If the Bypass mode was entered from Normal mode, wait approximately one minute
before trying to return to Normal mode. The UPS waits for internal voltages to bleed
down before proceeding to normal mode of operation. Press the UPS On button once
to return to the Normal mode.
Load Power-Off Mode
To switch to Load PowerĆOff from Bypass mode, hold the UPS Off button for three
seconds. The alarm sounds while the UPS Off button is held, and the Bypass indicator
goes off when the bypass voltage is removed from the load. Press the UPS On button
once to return to Bypass mode.
If Bypass is not enabled or the Bypass indicator is blinking (indicating that Bypass is
not available), the UPS enters Load PowerĆOff mode from Normal mode. To switch to
Load PowerĆOff from Normal mode, hold the UPS Off button for three seconds. The
alarm sounds while the UPS Off button is held, and the Normal indicator goes off when
the voltage is removed from the load. The UPS waits for internal voltages to bleed
down before proceeding to Normal mode of operation. Press the UPS On button once
to return to the Normal mode.
Load PowerĆOff can also be entered by turning off (O) the output breaker.
Audible Alarm
An audible alarm sounds a pulsing tone when the UPS is in Overload or OnĆBattery
mode. When there is one minute or less of battery time remaining, a constant tone
sounds. The alarm also sounds a constant tone if the UPS is on battery and the
UPS battery is disconnected (battery breaker is open or battery disconnected).