Hitachi SJ300 - Manual (Page 31)

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.
X
Refer to
2.1. Installation
Ambient temperature:
-10 ~ +50°C (no icing)
No condensation
Devices
overall
Check for abnormal vibrations
and noise.
X Visual 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
X Visual inspection No abnormalities
Cleaning X
Conductors /
cables
No change in shape? X Visual 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 X Visual inspection No abnormalities
Check for swelling X Visual inspection No abnormalities
Check for capacitance X With capacitance meter
85% or more of rated
capacitance
Relay, contactor
Check for stuttering noise during
operation
X Aural inspection No abnormalities
No damage of contact? X Visual inspection No abnormalities
Resistors
Check for cracks or
changes in color
X Visual inspection No abnormalities
No open circuit? X Tester check
Tolerance of within
± 10% of rated value
Cooling fan
Check for abnormal
vibration and noise
X
Rotate manually
during power off
Smooth rotation and
no abnormalities
Cooling
Check for dust X Visual inspection No abnormalities
Operation check
Check the balance of the output
voltage of each phase to phase
without motor.
X
Measure 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.
X
Simulate operation of the
protection circuit
Each protection should
be performed
Display
No illegible display;
No missing characters;
No segment failure of LEDs
X Visual 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