Service manual

19 BUS fault
05
Keep Buzzing
1. Don’t let the UPS
carry half-wave
load, negative
power load. Low PF
inductive/capacitive
load.
2. Don’t connect the
UPS (inverter)
output to the mains
line.
3. Check the BUS
voltage measurement
circuit.
20 Over charger
11
Keep Buzzing
1. Check the battery
Number.
2. Check the charging
voltage
measurement
circuit.
22 Line input site fault (L-N)
09
Once /2mins
1. Correct the wiring
2. Check the site-fault
detection circuit
3. Replace the global
controller
23 Battery / charger Fail
13
Once/s
1. Check the battery
Number
2. Check validation o
f
the BATTERY
3. Check the battery
voltage
measurement circuit
25 Fans fault
10
Once/s
1. Replace the Fans
2. Check and repai
r
the fans detection
circuit
Common Trouble Possible Cause And Solution
 Transfer to Bypass Due to Output Overload
Possible Cause: O/P load is larger than rated load in VA or in Wattage.
Solution: Removed or reduce load connected to O/P socket. On line mode, the UPS will restart
automatically. On battery mode, UPS must be OFF in advance and ON again.
 Transfer to Bypass Due to Over-temperature
Possible Cause 1:Ambient Temperature is higher than allowed operation temperature.
Solution: Reduce ambient temperature or O/P load.
Possible Cause 2: Thermal detection circuit failed.
Solution: Refer to the thermal detection problem Solution on later pages.
 Transfer to Bypass Due to DC Bus Over-voltage
Possible Cause 1: Some non-fatal misbehavior of UPS.
Solution: Turn off UPS and restart the UPS.
Possible Cause 2: PFC circuit fails.
Solution: Refer to PFC circuit failure analysis.
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