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Fig 5.5
2. The UPS Bypass loop is also equipped with overload protection. Its overload
capacity is illustrated by the graph & table below.
5.5. Inverter Failure
Output Load short circuit when supply via inverter
If output load is short circuited while supply via Inverter, the UPS will shutdown
Inverter automatically and stop supply to the loads. The Fault LED lights up
and the buzzer will beep continuously. The UPS will not switch on
automatically after short circuit condition is eliminated. The UPS has to be re-
start manually (refer to 4.5.1 ‘Start Up in Normal AC Mode’).
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5.6. Inverter/Internal Over temperature
If the UPS experiences internal over-temperature when Utility is normal, it will
switch to bypass loop. The UPS will switch back to inverter mode when the
over-temperature situation is eliminated. If over temperature occurs when
Utility is abnormal, the buzzer will beep continuously and the Fault LED
will light up. The UPS will cut off supply to the loads.
5.7. Inverter Over
-current and Inverter Output Voltage Out of tolerance
If the UPS inverter delivers over-current and out-of-tolerance voltage to its
outlets, the UPS is out of order. The UPS will switch to bypass loop when
Utility is normal. The Utility
LED, Bypass
LED and Fault
LED will
light up.
If these two fault conditions occur when Utility is abnormal, the UPS will cut
off the supply to its outlets and the Fault
LED will light up.
