Hitachi WJ C1 Series

Chapter 16 Maintenance and Inspection
16-2-5
16.2.5 Smoothing Capacitor Life Curve
*1. The ambient temperature is a temperature measured at a position about 5 cm from the bottom
center of the inverter (atmospheric temperature). If the inverter is installed in the cabinet, it is
the temperature inside the cabinet.
*2. The smoothing capacitor is a finite life component which occurs chemical reaction inside,
replacement is required after 10 years of use (It is a designed expected life, not a guaranteed
value).
However, if the inverter is used in an environment at high temperature or in a heavy-load
environment where its rated current is exceeded, the life is significantly shortened.
16.2.6 Life Warning Output
 By the self-diagnostic, it is possible to output an alarm in regards of the inverter own internal
components lifespan when the lifespan is nearing to its end (the cooling fan and the circuit
board electrolytic capacitor excluding the main circuit smoothing capacitor). Use this to get a
reference for when the components should be replaced.
 The life diagnostics of the electrolytic capacitor on the board and the cooling fan can be
checked with "Capacitor life warning [WAC] (39)" and Cooling-fan life warning [WAF] (40)"
output terminals or "Life assessment monitor [d022]". For details, see "9.11.7 Outputting a
Warning of Capacitor Life on the Control Board", "9.11.8 Outputting a Warning of Cooling Fan
Life", and "10.3.3 Monitor the Results of Lifetime Diagnosis", respectively. Since these alarms are
based on the design lifespan (not guaranteed values), problems may arise depending on the
environment, the operation conditions, etc. It is recommended an early maintenance.
Ambient temperature
*1
(°C)
10
20
30
40
50
0
-10
1
2
3
4
5
6
7
8
9
10
Capacitor life (years)
In the case of 24-hour energization/day and
driving at 80% of ND rated current
In the case of 24-hour
energization/day and driving at 100%
of ND rated current