B&C Technologies DI-325 Industrial - Manual (Page 31)

ROUTINE MAINTENANCE
6-4
1. DC bus capacitor
Measure the capacitance of the DC bus capacitor as follows:
The capacitance is displayed in the reduction ratio (%) of the initial value written in the
inverter memory before shipment.
Capacitance measurement procedure
1. Remove the RS485 communications card (option) from the inverter if it is mounted.
Disconnect the DC bus link circuit to other inverters from terminals P (+) and N (-) of the
main circuit if any. A DC reactor (option) and braking resistor (option) may not be
disconnected. Keep the ambient temperature at 25 + 10 °C.
2. Turn off the digital inputs (FWD, REV, and X1 to X3) at the control terminals.
- If an external potentiometer is connected, to terminal (13), remove it.
- Set the data of function codes E20 and E27 as the transistor output (Y1) or relay output
(30A, B, C) does not come on while the inverter power is turned off. E.g. recommended
settings are to assign normal logic signal (RUN) and (ALM) to terminals (Y1) and
(30A, B, C,) respectively.
3. Turn the inverter power on.
4. Check that the cooling fan rotates and the inverter is on halt.
5. Turn the main power supply off. Start measuring the capacitance of the DC bus capacitor.
6. After the LED monitor is unlit completely, turn the main power supply on again.
7. Select Menu #5 “Maintenance Information” in Programming mode, and check the
reduction ratio (%) of the capacitance of the DC bus capacitor.
2. Electrolytic capacitor on the printed circuit board
The inverter keeps an accumulative total of the number of hours that power has been applied to
the control circuit and displays it on the LED monitor. Use this to determine when the capacitor
should be replaced. The display is in units of 1000 hours.
3. Cooling fan
The inverter accumulates hours for which the cooling fan has run. The display is in units of
1000 hours.
The accumulated time should be used just a guide since the actual service life will be
significantly affected by the temperature and operation environment.