Maintenance And Inspection; Daily Inspection - Mitsubishi Q2ACPU User Manual

21.

MAINTENANCE AND INSPECTION

21 MAINTENANCE AND INSPECTION
In order to use the PLC always in good condition, conducting daily and periodical
maintenance/inspection on the following items are strongly recommended.

21.1 Daily Inspection

Dairy inspection items recommended are shown in Table 21.1.
Item
1
2
3
4
REMARK
Check item Content of inspection
Confirm if installation
Installation condition
screws are not loose or
of the base unit
cover is not detached.
Check if the module is
Installation condition not disengaged and if
of the I/O modules the hook is securely
engaged.
Loosening of terminal
screw.
Connection Proximity of solderless
conditions terminals.
Connector areas of
extension cable.
Power supply
module Confirm it is ON.
POWER LED
CPU module Confirm it is ON in the
"RUN" LED "RUN" state.
CPU module Check that the LED is
"ERROR" LED OFF.
CPU module Check that the LED is
"BAT. ARM" LED OFF.
Input module Confirm if it correctly
LED turns on and off.
Output module Confirm if it correctly
LED turns on and off.
If an I/O module has to be replaced when the system is running, use the "online I/O
module replacement" function.
Table 21.1 Daily inspection
Judgement
It is installed securely.
The hook should be securely
engaged and the module
should be positively
mounted.
No loosening.
There is an appropriate
distance.
No loosening at connectors.
The LED is ON.
(Faulty if it is OFF.)
The LED is ON.
(Faulty if it is OFF.)
OFF
(Faulty if it is ON or
flickering.)
OFF
(Faulty if it is ON.)
The LED is ON when input is
ON, and OFF when input is
OFF.
(Faulty other than the above.)
The LED is ON when output
is ON, and OFF when output
is OFF.
(Faulty other than the above.)
21 - 1
Action
Retighten the screw.
Securely engage the
hook.
Retighten the terminal
screw.
Correct the distance.
Retighten the
connector fixing screw.
Refer to Section 22.2.2.
Section 22.2.3.
Refer to
Section 22.2.4.
Refer to Section 22.2.5.
Refer to Section 22.2.7.
Refer to Section 22.2.8.
Refer to Section 22.2.8.