Fuji Electric FRENIC-Ace series - At Power Shutdown

5.3 Description of Function Codes
5-172
[ 2 ] Measuring the capacitance of DC link bus capacitor under ordinary operating
conditions at power shutdown
When bit 3 of H98 data is 1, the inverter automatically measures the capacitance of the DC link bus capacitor
under ordinary operating conditions when the power is turned OFF. This measurement requires setting up the load
conditions for ordinary operation and measuring the reference capacitance when the inverter is introduced to the
practical operation, using the setup procedure given below.
Function code Name Data
H42 Capacitance of DC link bus
capacitor
• Capacitance of DC link bus capacitor (measured
value)
• Start of initial capacitance measuring mode under
ordinary operating conditions (0000)
• Measurement failure (0001)
H47 Initial capacitance of DC link
bus capacitor
• Initial capacitance of DC link bus capacitor (measured
value)
• Start of initial capacitance measuring mode under
ordinary operating conditions (0000)
• Measurement failure (0001)
When replacing parts, clear or modify the H42 and H47 data. For details, refer to the maintenance related
documents.
---------------------------------------Reference capacitance setup procedure--------------------------------------
1) Set function code H98 (Protection/maintenance function) to enable the user to specify the judgment criteria
for the service life of the DC link bus capacitor (Bit 3 = 1) (refer to function code H98).
2) Turn OFF all run commands.
3) Make the inverter ready to be turned OFF under ordinary operating conditions.
4) Set both function codes H42 (Capacitance of DC link bus capacitor) and H47 (Initial capacitance of DC link
bus capacitor) to “0000”.
5) Turn OFF the inverter, and the following operations are automatically performed.
The inverter measures the discharging time of the DC link bus capacitor and saves the result in function code
H47 (Initial capacitance of DC link bus capacitor).
The conditions under which the measurement has been conducted will be automatically collected and saved.
During the measurement, “ . . . . ” will appear on the LED monitor.
6) Turn ON the inverter again.
Confirm that H42 (Capacitance of DC link bus capacitor) and H47 (Initial capacitance of DC link bus
capacitor) hold right values. Shift to Menu #5 “Maintenance Information” and confirm that the relative
capacitance (ratio to full capacitance) is 100%.
If the measurement has failed, “0001” is entered into both H42 and H47. Remove the factor of the failure
and conduct the measurement again.
----------------------------------------------------------------------------------------------------------------------------------
Hereafter, each time the inverter is turned OFF, it automatically measures the discharging time of the DC link bus
capacitor if the above conditions are met. Periodically check the relative capacitance of the DC link bus capacitor
(%) with Menu #5 “Maintenance Information” in Programming mode.
The condition given above tends to produce a rather large measurement error. If this mode gives you a
lifetime alarm, set H98 (Protection/maintenance function) back to the default setting (Bit 3 (Select life
judgment threshold of DC
link bus capacitor) = 0) and conduct the measurement under the condition at
the time of factory shipment.