Mitsubishi Electric FR-CC2-P, Instruction Manual

Page: 158 / 184

Inspection item
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
157
7
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 tester. (For the resistance measurement, use the 100

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

to
several tens of

. If all measured values are almost the same, although these values are not constant depending on the
module type and tester type, the modules are without fault.
 Semiconductor device numbers and terminals to be checked
(Assumes the use of an analog meter.)
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.
Converter
unit
Tester polarity
Result
D1
R/L1 P/+ Discontinuity
P/+ R/L1 Continuity
D2
S/L2 P/+ Discontinuity
P/+ S/L2 Continuity
D3
T/L3 P/+ Discontinuity
P/+ T/L3 Continuity
D4
R/L1 N/- Continuity
N/- R/L1 Discontinuity
D5
S/L2 N/- Continuity
N/- S/L2 Discontinuity
D6
T/L3 N/- Continuity
N/- T/L3 Discontinuity
Converter unit
D1 D2 D3
D4 D5 D6
R/L1
S/L2
T/L3
C
P/+
N/-