Daily And Periodic Inspection - Hitachi EHV+ Series Applications Manual

Chapter5 Maintenance
In order to use the PLC in the best condition and maintain the system to operate properly, it is necessary to conduct
daily and periodic inspections.
5.1

Daily and Periodic Inspection

(1) Daily inspection
Verify the following items while the system is running.
Item
Power module display
CPU module display
*1 If power off time is more than 1 week after battery error detected (ERR LED blinking), retain data and realtime clock
data could be lost due to battery empty. If power off time is long enough, it is possible that a battery becomes empty
while this power failure. In that case, retain data and realtime clock data would be already lost in the next power up.
(2) Periodic inspection
Turn off the power for the external I/O circuit, and check the following items once every six months.
Part
Programming device
to CPU
Power supply
I/O module
Battery
(Lithium battery)
Installation and
connecting areas
Ambient environment (1) Temperature
Spare part
Program
Table 5.1 Items for daily inspection
LED display Inspection
method
POW Visual check
RUN Visual check
ERR Visual check
7-segment Visual check
Table 5.2 Items for periodic inspection
Item
Check the operation of the
programming device
Check for the voltage fluctuations
Output relay life
LED
External power voltage
Check voltage and life
(1) All module are securely fixed.
(2) All command fits snugly.
(3) All screw is tight.
(4)All cables are normal.
(2) Humidity
(3) Others
Check the number of parts, the
storage condition
Check program contents
Normal status
ON Power supply error, etc.
ON OFF:
R unning Microprocessor error, memory error, etc.
（ ）
Refer to chapter 3 for further information.
OFF ON:
Serious errors such as microprocessor error or
memory error, etc. Refer to chapter 3.
Blink:
Battery error (71 error)
00 Self-diagnosis error code is displayed.
Refer to chapter 3.
Check criteria
All switch and display lamps work
properly.
85 to 264 V AC
Electrical life 200,000 times
Mechanical life 10 million times
Turns ON/OFF correctly
Within the specification for each
I/O module.
ERR lamp flashes.
Within 2 years after replacement.
No defects
0 to 55 °C
20 to 90 % RH (no condensation)
No dust, foreign matter, vibration
No defects
Compare the contents of the latest
program saved and CPU contents,
and make sure they are the same.
5 – 1
Main cause of error
Remarks
Tester
Refer to the relay contact
file curve (chapter 4).
Refer to the
specifications of I/O
module
Tighten
Check insertion
Tighten
Visual check
Visual check
Visual check
Check both master and
backup.