Mitsubishi Electric FR-D720S SC EC Instruction Manual page 424

Useful functions
Control circuit capacitor life display (Pr. 257)
The deterioration degree of the control circuit capacitor is displayed in Pr. 257 as a life.
In the operating status, the control circuit capacitor life is calculated from the energizing time and
temperature of the inverter's heatsink, and is counted down from 100%. As soon as the control
circuit capacitor life falls below 10%, Pr. 255 bit 0 is turned on and also an alarm is output to the
Y90 signal.
Main circuit capacitor life display (Pr. 258, Pr. 259)
The deterioration degree of the main circuit capacitor is displayed in Pr. 258 as a life.
On the assumption that the main circuit capacitor capacitance at factory shipment is 100%, the
capacitor life is displayed in Pr. 258 every time measurement is made. When the measured val-
ue falls to or below 85%, Pr. 255 bit 1 is turned on and also an alarm is output to the Y90 signal.
Measure the capacitor capacity according to the following procedure and check the deteriora-
tion level of the capacitor capacity.
Check that the motor is connected and at a stop.
Set "1" (measuring start) in Pr. 259.
Switch power off. The inverter applies DC voltage to the motor to measure the capacitor
capacity while the inverter is off.
After confirming that the LED of the operation panel is off, power on again.
Check that "3" (measuring completion) is set in Pr. 259, read Pr 258, and check the
deterioration degree of the main circuit capacitor.
Pr. 259
Tab. 6-95: Parameter 259
When the main circuit capacitor life is measured under the following conditions, "forced end"
(Pr. 259 = 8) or "measuring error" (Pr. 259 = 9) occurs or it remains in "measuring start" (Pr. 259
= 1). Therefore, do not measure in such case. In addition, even when "measurement comple-
tion" (Pr. 259 = 3) is confirmed under the following conditions, normal measurement can not be
done.
³ FR-HC or FR-CV is connected.
· DC power supply is connected to the terminal P/+ and N/−.
» The power supply switched on during measurement.
¿ The motor is not connected to the inverter.
´ The motor is running. (The motor is coasting.)
² The motor capacity is two ranks (or more) smaller as compared to the inverter capacity.
¶ The inverter is at an alarm stop or an alarm occurred while power is off.
º The inverter output is shut off with the MRS signal.
¾ The start command is given while measuring.
µ The parameter unit (FR-PU04/FR-PU07) is connected.
¸ Use terminal PC as power supply.
¹ I/O terminal of the control terminal block is on (continuity).
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Description
0 No measurement
Measurement start
1
2 During measurement
3 Measurement complete
8 Forced end (see
9 Measurement error (see
, , , below)
, , below)
Remarks
Initial value
Measurement starts when the power supply is
switched off.
Only displayed and cannot be set
Parameter