UNINTERRUPTIBLE POWER SUPPLIES
Maintenance Frequency
Description Comment Daily Monthly
1. Cubicle. a) check condition and clean,
b) check integrity of doors and panels,
including locks,
c) check for ease of operation of
switches, isolators and circuit
breakers,
d) check condition of contactors
e) check shrouds are in position,
f) check indicator lamps and lenses,
replace as necessary.
2. Fuses Check for correct rating of fuses and
and MCBs. settings
3. Relays, Check forand operation
burn of MCBs.
marks and tightness of
contactors connections.
and wiring.
4. Earthing. Ensure all sub assemblies with
electrical components mounted on are
adequately earthed.
5. Switch on and check:
Rectifier.
a) battery trickle charge voltage,
b) battery charge voltage level.
6. Rectifier Check and record 'pick-up' and 'drop
alarms. out' voltages of all alarm relays.
7. Rectifier Check and record.
waveform.
8. Inverter. Switch on and check the Inverter
Control Unit control voltage. When
operating correctly, check and record
the output voltage and frequency.
9. Inverter Check for correct operation and check
alarms. 'pick-up' and 'drop out' voltages of all
A.C. and D.C. alarm relays.
10. Inverter Check and record the output
wave waveform.
forms.
11. Static Check operation with both rectifier and
power inverter switched on.
switch.
12. Output. Check:
a) inverter output voltage and
frequency,
b) bypass voltage and frequency,
c) load transfer,
d) load voltage and power.
13. Batteries.
a) lead acid, Check condition.
b) other types. Check condition and report to client if
replacement is required.
quency
Quarterly H Yearly Yearly NOTES
x All dirt and foreign bodies
should be removed.
x
x Shrouds should be fitted over
terminals of electrolytic
capacitators if visible with doors
open and where live conductors
are in proximity to operational
devices.
x
x Where star washers are used
for earth connections make
sure earth connection is good.
x
x Check and record calibration of
all meters on the equipment.
x Compare with voltages
recorded on test
certificate.Record the results
and report any significant
differences. Check and record
the calibration of all meters.
x
x
x
x
x
x Measure and record.
x
x
x Batteries should be disposed of
only in accordance with
statutory recommendations.
Uninterruptible Power Supply (UPS) PPM Checklist
Maintenance Frequency
Description Comment Daily Monthly Quarterly H Yearly
Connections Visually inspect equipment for loose
connections X
Conduct thermal scans on electrical
connections to ensure all are tight
and not generating heat
X
Insulation Visually inspect for burnt insulation
Batteries and Visually check for liquid
Capacitors contamination X
Equipment Clean and vacuum UPS equipment
enclosures enclosures X
Transfer switches Visually inspect equipment for loose
connections X
Circuit breakers Visually inspect equipment for loose
connections X
Cubicle Check condition and clean. Check
integrity of doors and panels,
including locks. X
Check for ease of operation of
switches, isolators and circuit
breakers X
Check condition of contactors
X
Fuses and MCBs Check for correct rating of fuses and
settings X
Check the operation of MCBs
X
Relays, contactors Check for burnt marks and tighten
connections X
Check the wiring for any defects
X
Earthing Ensure all sub-assemblies with
electrical components mounted on
are adequately earthed
X
Rectifier Switch on and check: Battery trickle
charge voltage, battery charge
voltage level
X
Rectifier alarms Check and record pick-up and
drop-out voltages of all alarm relays
X
Rectifier waveform Check and record the rectifier
waveform X
Inverter Switch on and check the inverter
control unit control voltage.
X
When operating correctly, check and
record the output voltage and
frequency X
Inverter Alarm Check for correct operation and
check pick-up and drop-out
voltages of all AC & DC alarm relays
X
Inverter wave forms Check and record the output
waveform X
Static power switch Check operation with both rectifier
and inverter switched on
X
Output Check inverter output voltage and
frequency; bypass voltage and
frequency , load transfer
X
Yearly
X
X
