Hitachi IR.Station, Hardware Manual

Page: 49 / 54

7 MAINTENANCE
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Dust adhesion check
Check if dust or other foreign matter adhered on the module. If any dust/foreign matter
buildup is found, remove it with a vacuum cleaner. If you allow dust or other foreign
matter to build up, the internal circuitry may be shorted or to cause a component burnout.
Supply voltage check
Check that the voltages of the module power supply and externally supplied power are
within the specified ranges. If the supply voltage is out of the range, the system may
malfunction. (For the modules' operating supply voltages and externally supplied voltage,
refer to the respective manuals.)
Life expectancy of the relay
As regards the LQY100, LQY140, and other I/O modules having a built-in relay, you must
pay attention to the life expectancy of the relay.
If the relay opens/closes at frequent intervals or is incorporated in a system having a high
output voltage or current, you should consider a module replacement.
20
30
50
100
200
300
500
1000
2000
10
0.02 0.05 0.1 0.2 0.3 0.5 1.0 2.0
110
VDC L load (L/R=7 ms)
220
VA
C L load (COS
φ
=0.4)
120
VA
C L load (COS
φ
=0.4)
120
VA
C R load, 24
VDC L load (L/R=7 ms)
110
VDC R load
220
VA
C R load
24
VDC R load
Load current (A)
Life (10
4
switchings)
The L load contains a rush current.
Figure 7-1 Life Expectancy of Relay