APC 900XL Power Supply User Manual


 
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5.0 Operation
5.6 Option switches - continued
5.6.2 Option switch 2
Option switch 2 controls different functions depending upon the UPS version type.
120 Vac version
The UPS's factory set input voltage limits for on-line and SmartBoost operation are given
in section 9.0 and are centered on the nominal input voltage of 120 Vac. When Option
switch 2 is set to the on ( I ) position, the upper and lower transfer voltages are lowered
by 4% and are centered on a nominal input of 115 Vac. This option is useful where the
nominal input voltage is 110 to 115 Vac.
220/230/240 Vac version
The UPS's factory set on-battery output voltage and input voltage limits for on-line and
SmartBoost operation are appropriate for use in regions where the nominal line voltage
is 220 to 230 Vac. When Option switch 2 is set to the on ( I ) position, the upper and lower
transfer voltages are raised by 4% and are centered on a nominal input of 240 Vac. In
addition, the on-battery output voltage is increased to 240 Vac.
5.6.3 Option switch 3
When Option switch 3 is set to the on ( I ) position, the UPS's audible alarm is disabled for
the first 30 seconds of an extended utility fault. This function is useful where brief power
interruptions are frequent and cause the alarm to become annoying.
5.6.4 Option switch 4
When Option switch 4 is set to the on ( I ) position, the UPS's low battery warning interval
before shutdown due to battery capacity exhaustion is extended. This function is useful
where the UPS is protecting a computer system that requires a longer warning interval
before power loss to perform a graceful shutdown.