Service manual

6. TROUBLE SHOOTING
Despite of careful design and strict tests, in case UPS become out of order. Basically,
designer suggest following service procedure:
1. Check the UPS status by LCD panel display, or listen to the end user description
2. Identify the failure part/boards with the help of failure identify flowchart.
3. Observe the failure board, Static checking
4. Replace the failure components with OK parts
5. Static checking
6. Power up checking
7. Test after repair.
Following section will help service person to solve the most problems.
6.1 LCD Panel Display Definition
No.
Operation Mode The warning or fault code
Alarm
frequency
Suggestion for service
people
1 Line mode / NO Alarm
2
0％-25％ battery level
12
Once/s
3
Battery
mode
26％-100％ battery level
/
Once/4s
4 Bypass mode operation
/
Once/2 mins
5
Transfer to bypass mode for over
load
07
Keep Buzzing
Remove over load and
restart the UPS
6
Over load, before transfer to
bypass
/
Twice per sec Remove the over load
17 Over-temperature Fault
08
Keep Buzzing
1. Don’t let the UPS
the work in ambient
temperature ove
r
specification
2. Make sure the
ventilation is good
3. Check the fans
4. Check the
temperature
measurement circuit
18 Inverter output Fault
06
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 if the output
is short-circuit
3. Check the Inverte
r
voltage measurement
circuit
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