AEC IST3-J, User Manual

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User Manual UPS IST3-J 4 Operation and Maintenance
23
Table4-1 Troubleshooting
Fault phenomenon Possible reason
The mains normal. After starting
the UPS, it outputs normally, but
it works in the battery mode and
the buzzer beeps intermittently.
1) Check if the contactors and sockets in the input
circuit are in good condition;
2) Check if the displayed input voltage amplitude or
frequency of mains on the LCD is beyond the
allowable range of UPS;
3) Check if the over-current protector in the rear
panel is sprung. If yes, press the over-current
protector switch.
After installing UPS, connecting
with power will fuse the fuse or
cause tripping operation.
UPS output is short circuit.
After starting, the LCD display
and output are normal. But once
connecting with load, it will stop
outputting immediately.
1) UPS is overload seriously or the output circuit is
short-circuit. Please reduce load to proper
capacity or find the short-circuit reason. The
common reason is that the output changeover
socket short-circuit or the input short-circuit after
UPS damage.
2) The load is not started according to "high power
device → small power device". Restart the UPS,
and after the UPS works steadily, start high power
load first, and then start small power ones
successively.
Buzzer long beeps, fault
indicator lights on, UPS works in
bypass mode and inverter
failure.
1) The output is overload. The load is too heavy and
beyond the rated power of the UPS. Please
reduce load or select a UPS with larger power
capacity. If it is temporary bypass caused by
impact of load start and recovers automatically, it
still is normal.
2) UPS over-temperature protection. Check if the air
inlet and air outlet of UPS is blocked or the
working temperature of UPS is beyond the