Capacitor Life Curves - Omron 3G3MX2 User Manual

Maintenance and Inspection
6-4-6

Capacitor Life Curves

286
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.
Variable-frequency Drive
Power
Input
Converter
Internal
DC Bus
L1
Rectifier
L2
L3
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.
50
Ambient
temperature, °C
40
30
20
10
0 1
Inverter
Capacitor Life Curve
2 3 4 5 6
Section 6-4
Motor
U/T1
V/T2
W/T3
Operation 24 hours/day, 80% load
Operation 24 hours/day, 100% load
Years
7 8 9 10