
10. MAINTENANCE AND INSPECTION
10 - 3
MELSEC-A
10.2
Periodic Inspection
This section explains the inspection items which are to be checked every six
months to one year. This inspection should also be performed when the equipment
is moved or modified or the wiring is changed.
Table 10.2 Periodic inspection
No.
Check item
Check point
Judgement
Corrective action
Ambient
temperature
0 to 55 °C
1
Ambient
humidity
10 to 90 % RH
Ambience
There should be
no corrosive gases.
2
85 to 132 V AC
170 to 264 V AC
3
Looseness,
play
Move the module.
The module
should be
mounted securely
and positively.
Retighten screws.
Ingress of
dust or
foreign
material
Visual check.
There should be
no dust or foreign
material in the
vicinity of the PLC.
Remove and clean.
Loose
terminal
screws
Retighten.
Connectors should
not be loose.
Retighten.
4
Distances
between
Solderless
terminals.
Visual check.
The proper
clearance should
be provided
between
Solderless
terminals.
Correct.
Loose
connector
Visual check.
Connectors should
not be loose.
Retighten
connector
mounting screws.
5
Battery
Check battery
status by mounting
special auxiliary
relays M9006 and
M9007.
Preventive
maintenance
If battery capacity
reduction is not
indicated, change
the battery when
specified service
life is exceeded.
Mou
n
ting
c
ondit
ion
s
C
onn
ec
ting c
o
ndit
ion
s
Measure whit
thermometer and
hygrometer.
Measure corrosive
gas.
When PLC is used
inside a panel, the
temperature in the
panel is the
ambient
temperature.
Change supply
power.
Line voltage
check.
Measure voltage
across 100/200 V
AC terminal.
A
m
b
ien
t env
ironm
ent
Summary of Contents for A1SH
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