4200FA XT1
September 6, 2004
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2) INPUT ISOLATION TRANSFORMER - The inverter network shall
incorporate a shielded isolation transformer to provide complete isolation
of the load from utility AC, as well as providing attenuation for high
frequency noise common mode). Additionally, the transformer shall have
a set of windings to condition the internal static bypass line.
3) OVERCURRENT PROTECTION - The output circuitry shall be
equipped with a Hall Effect Current Transformer to detect and protect the
inverter from excessively high currents.
C. Static Bypass Switch
1) TRANSFER - The static bypass switch shall consist of thyristor
switches in conjunction with an output contactor to permit manual
switching from bypass to UPS and UPS to bypass without power
interruption. The UPS shall instantaneously transfer to bypass should a
component fail during normal operation (provided the UPS and bypass are
in synchronization). Auto-retransfer to UPS after an overload condition
shall be completed within one second after the bus has dropped to 100%
of nominal.
2) REMOTE RUN/STOP - A set of normally open dry contacts shall be
provided to remotely transfer the UPS on-line and off-line. When the UPS
is in this mode of operation, the UPS front control panel shall be disabled
to provide a secured configuration.
D. Microprocessor Control System
1) DESCRIPTION - The UPS system shall be provided with a highly
reliable microprocessor internal control system to perform start-up,
transfers, monitoring, and battery recharging. The microprocessor shall
provide important information to the user (via a liquid crystal display) with
such as system status, fault messages and input and output parameters.
2) LED INDICATORS - The following LED indicators shall be provided on
the UPS front panel displays, which mimic power flow through the UPS:
a) AC INPUT (Green Lamp) - Lights when normal AC input power
is being supplied to the unit.
b) INVERTER (Green Lamp) - Lights when the UPS unit’s inverter
is normal.
c) BATTERY (Green Lamp) - Lights when the batteries are
discharging: flickers when the battery voltage is below minimum.
d) BYPASS (Green Lamp) - Lights when in circuit-bypass mode.
d) FAULT (Red Lamp) - Lights when a fault has been detected.