7-2
Table 7.1 List of Periodic Inspections (Continued)
Check part
Check item
How to inspect
Evaluation criteria
Keypad
1) Check that the display is clear.
2) Check that there is no missing part
in the displayed characters.
1), 2)
Visual
inspection
1), 2)
The
display
can
be read and
there is no fault.
Structure such
as frames and
covers
Check for:
1) Abnormal noise or excessive
vibration
2) Loose bolts (at clamp sections)
3) Deformation or breakage
4) Discoloration caused by overheat
5) Contamination or accumulation of
dust or dirt
1) Visual or auditory
inspection
2) Retighten.
3), 4), 5)
Visual
inspection
1), 2), 3), 4), 5)
No
abnormalities
Common
1) Check that bolts and screws are
tight and not missing.
2) Check the devices and insulators
for deformation, cracks, breakage
and discoloration caused by
overheat and deterioration.
3) Check for contamination and
accumulation of dust or dirt.
1) Retighten.
2), 3)
Visual
inspection
1), 2), 3)
No
abnormalities
Conductors
and wires
1) Check conductors for discoloration
and distortion caused by overheat.
2) Check the sheath of the wires for
cracks and discoloration.
1), 2)
Visual
inspection
1), 2)
No
abnormalities
Terminal
blocks
Check that the terminal blocks are not
damaged.
Visual inspection
No abnormalities
DC link bus
capacitor
1) Check for electrolyte leakage,
discoloration, cracks and swelling
of the case.
2) Check that the safety valve does
not protrude remarkably.
3) Measure the capacitance if
necessary.
1), 2)
Visual
inspection
3) Measure the
discharge time
with capacitance
probe.
1), 2)
No
abnormalities
3) The discharge
time should not
be shorter than
the one specified
by the
replacement
manual.
Braking
resistor
1) Check for abnormal odor or cracks
in insulators, caused by overheat.
2) Check for broken wires.
1) Olfactory and
visual inspection
2) Check the wires
visually. Or
disconnect either
wire and measure
the conductivity
with a multimeter.
1) No abnormalities
2) Within ± 10% of
the resistance of
the braking
resistor
Main circuit
Transformer
and reactor
Check for abnormal roaring noise and
odor.
Auditory, visual and
olfactory inspection
No abnormalities
