Mitsubishi Electric FR-CC2-N Series, Instruction Manual

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7. PRECAUTIONS FOR MAINTENANCE AND INSPECTION
7.1 Inspection item
NOTE
• Continuous use of a leaked, deformed, or degraded smoothing aluminum electrolytic capacitor (as shown in the table above)
may lead to a burst, breakage, or fire. Replace such capacitor without delay.
7.1.4 Checking the converter semiconductor devices
 Preparation
• Disconnect the external power supply cables (R/L1, S/L2, T/L3, P/+, and N/-).
• Prepare a continuity tester. (For the resistance measurement, use the 100
Ω range.)

Checking method
Change the polarity of the tester alternately at the converter unit terminals R/L1, S/L2, T/L3, P/+, and N/- and check the electric
continuity.
NOTE
• Before measurement, check that the smoothing capacitor is discharged.
• At the time of electric discontinuity, the measured value is almost
∞ . When there is an instantaneous electric continuity, due
to the smoothing capacitor, the tester may not indicate ∞ . At the time of electric continuity, the measured value is several Ω to
several tens of Ω . When all measured values are almost the same (although values may not be constant depending on the
tester type), it shows that there are no electrical paths with problems.
 Semiconductor device numbers and terminals to be checked
(Assuming that an analog meter is used.)
7.1.5 Cleaning
Always run the converter unit in a clean status.
When cleaning the converter unit, gently wipe dirty areas with a soft cloth immersed in neutral detergent or ethanol.
NOTE
• Do not use solvent, such as acetone, benzene, toluene and alcohol, as these will cause the converter unit surface paint to peel
off.
• The display, etc. of the operation panel are vulnerable to detergent and alcohol. Therefore, avoid using them for cleaning.
7.1.6 Replacement of parts
The converter unit 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 converter unit. For preventive maintenance, the parts must be replaced periodically.
Converter unit
Tester polarity
Continuity
D1
R/L1 P/+ No
P/+ R/L1 Yes
D2
S/L2 P/+ No
P/+ S/L2 Yes
D3
T/L3 P/+ No
P/+ T/L3 Yes
D4
R/L1 N/- Yes
N/- R/L1 No
D5
S/L2 N/- Yes
N/- S/L2 No
D6
T/L3 N/- Yes
N/- T/L3 No
Converter unit
D1 D2 D3
D4 D5 D6
R/L1
S/L2
T/L3
C
P/+
N/-