(2) Measuring method of life of the main circuit capacitor
If the value of capacitor capacity measured before shipment is considered as 100%, Pr. 255 bit1 is turned on when
the measured value falls below 85%.
Measure the capacitor capacity according to the following procedure and check the deterioration level of the
1) Check that the motor is connected and at a stop.
2) Set "1" (measuring start) in Pr. 259
3) Switch power off. The inverter applies DC voltage to the motor to measure the capacitor capacity while the
inverter is off.
4) After confirming that the LED of the operation panel is off, power on again.
5) Check that "3" (measuring completion) is set in Pr. 259, then read Pr .255 and check the life of the main circuit
The life of the main circuit capacitor can not be measured in the following conditions.
(a) FR-HC, MT-HC, FR-CV, FR-BU, MT-RC, MT-BU5 or BU is connected.
(b) Terminal R1/L11, S1/L21 or DC power supply is connected to the terminals P/+ and N/−.
(c) Switch power on during measuring.
(d) The motor is not connected to the inverter.
(e) The motor is running.(The motor is coasting.)
(f) The motor capacity is two rank smaller as compared to the inverter capacity.
(g) The inverter is at an alarm stop or an alarm occurred while power is off.
(h) The inverter output is shut off with the MRS signal.
(i) The start command is given while measuring.
· Operating environment:Ambient temperature (annual average 40°C (free from corrosive gas, flammable gas, oil mist, dust and
Output current (80% of the rated current of Mitsubishi standard 4P motor)
For the accurate life measuring of the main circuit capacitor, perform after more than 3h passed since the turn off of
the power as it is affected by the capacitor temperature.
Always run the inverter in a clean status.
When cleaning the inverter, gently wipe dirty areas with a soft cloth immersed in neutral detergent or ethanol.
Do not use solvent, such as acetone, benzene, toluene and alcohol, as they will cause the inverter surface paint to peel off.
The display, etc. of the operation panel (FR-DU07) and parameter unit (FR-PU04/FR-PU07) are vulnerable to detergent and
alcohol. Therefore, avoid using them for cleaning.
Replacement of parts
The inverter consists of many electronic parts such as semiconductor devices.
The following parts may deteriorate with age because of their structures or physical characteristics, leading to reduced
performance or fault of the inverter. For preventive maintenance, the parts must be replaced periodically.
Use the life check function as a guidance of parts replacement.
Main circuit smoothing capacitor
On-board smoothing capacitor
Fuse (160K or more)
*1 Replacement years for when the yearly average ambient temperature is 40°C
(without corrosive gas, flammable gas, oil mist, dust and dirt etc)
*2 Output current : equivalent to rating current of the Mitsubishi standard motor (4 poles)
For parts replacement, consult the nearest Mitsubishi FA Center.
Standard Replacement Interval
Replace (as required)
Replace (as required)
Replace the board (as required)
Replace the fuse (as required)