5- 2

5.2 Daily and annual maintenance
Interval
Item Contents
D
A
Method Criteria
Ambient
Environment
Check ambient temperature,
humidity, dust, corrosive gas, oil
mist, etc. XRefer to
2.1. Installation
Ambient temperature:
-10 ~ +50°C (no icing)
No condensation
Devices
overall Check for abnormal vibrations
and noise. XVisual inspection No abnormalities
Overall
Power supply
voltage Check voltage between
input lines X
Measure the voltage between
input terminals No abnormalities and
within specifications
Overall Megger check
(Power terminal - Earth) X
Remove connector J61
Disconnect power line
Remove logic terminal
Make short circuit R, S, T, U,
V, W, P, PD ,N ,RB
Megger test between above
and earth
> 5Mohm
Check installation for looseness.
X
Tighten No abnormalities
Check for evidence of over
heating in the various
components XVisual inspection No abnormalities
Cleaning X
Conductors /
cables No change in shape? XVisual inspection No abnormalities
No damage in coating?
X
Visual inspection No abnormalities
Terminal block
No damage?
X
Visual inspection No abnormalities
Mains
Inverter /
Converter Tester check between each
terminal X
Remove power cables
Measure resistance;
Each input ⇔ P, N
Each output ⇔ P, N
with 1ohm range
Refer to
“5.5 How to measure
inverter &
converter“ portion
DC bus capacitor Check for leaking liquid XVisual inspection No abnormalities
Check for swelling
X
Visual inspection No abnormalities
Check for capacitance XWith capacitance meter 85% or more of rated
capacitance
Relay, contactor
Check for stuttering noise during
operation XAural inspection No abnormalities
No damage of contact?
X
Visual inspection No abnormalities
Resistors Check for cracks or
changes in color XVisual inspection No abnormalities
No open circuit? XTester check Tolerance of within
±10% of rated value
Cooling fan Check for abnormal
vibration and noise XRotate manually
during power off Smooth rotation and
no abnormalities
Cooling
Check for dust
X
Visual inspection No abnormalities
Operation check
voltage of each phase to phase
without motor. XMeasure the output voltage
between U, V and W
Within 2% of voltage
difference between
each phases.
Control circuit
Perform a sequence protection
operation test and make sure
that there are no errors in the
protection and display circuits.
XSimulate operation of the
protection circuit Each protection should
be performed
Display No illegible display;
No missing characters;
No segment failure of LEDs XVisual inspection No abnormalities
Cleaning
X
LED
display
Meter Working correct? X X Visual inspection Displays correct value
Overall
No abnormal vibration & noise?
X
Visual, aural inspection No abnormalities
No abnormal smell? X
Confirm the smell caused by
overheat, damage etc. No abnormalities
Motor
Insulation
resistance Megger check
All terminals together - Earth X
Measure resistance;
Each input ⇔ Earth
With and without motor
cables
> 5Mohm