Omron MX2 - Capacitor Life Curves

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Maintenance and Inspection Section 6-4
6-4-6 Capacitor Life Curves
The DC bus inside the inverter uses a large capacitor as shown in the dia-
gram below. The capacitor handles high voltage and current as it smoothes
the power for use by the inverter. So, any degradation of the capacitor will
affect the performance of the inverter.
Capacitor life is reduced in higher ambient temperatures, as the graph below
demonstrates. Under the condition of average ambient temperature 40°C,
80% load, 24 hours operation, the lifetime is 10 years. Be sure to keep the
ambient temperature at acceptable levels, and perform maintenance inspec-
tions on the fan, heat sink, and other components. If the inverter is installed on
a cabinet, the ambient temperature is the temperature inside the cabinet.
Rectifier
Motor
Inverter
Converter
Internal
DC Bus
Power
Input
L1
L2
L3
U/T1
V/T2
W/T3
Variable-frequency Drive
50
Years
Operation 24 hours/day, 100% load
40
30
20
10
1 2 3 4 5 6 7 8 9 10
Operation 24 hours/day, 80% load
Capacitor Life Curve
0
A
mbient
temperature, °C