Display Of The Life Of The Drive Unit Parts; Checking The Inverter And Converter Modules - Mitsubishi Electric FR-D720-0.2K-G Instruction Manual

Inspection items
6.1.4

Display of the life of the drive unit parts

The self-diagnostic alarm is output when the life span of the control circuit capacitor, cooling fan and each parts of the inrush
current limit circuit is near its end. It gives an indication of replacement time.
The life alarm output can be used as a guideline for life judgement.
Parts
Main circuit capacitor
Control circuit capacitor
Inrush current limit circuit
Cooling fan
POINT
Refer to page 231 to perform the life check of the drive unit parts.
6.1.5

Checking the inverter and converter modules

<Preparation>
(1) Disconnect the external power supply cables (R/L1, S/L2, T/L3) and motor cables (U, V, W).
(2) Prepare a tester. (Use 100 range.)
<Checking method>
Change the polarity of the tester alternately at the drive unit terminals R/L1, S/L2, T/L3, U, V, W,
continuity.
NOTE
1. Before measurement, check that the smoothing capacitor is discharged.
2. At the time of discontinuity, the measured value is almost
smoothing capacitor, the tester may not indicate
several tens-of ohms depending on the module type, circuit tester type, etc. If all measured values are almost the
same, the modules are without fault.
<Module device numbers and terminals to be checked>
Tester Polarity
R/L1 P/+ Discontinuity
D1
P/+ R/L1 Continuity
S/L2 P/+ Discontinuity
D2
P/+ S/L2 Continuity
T/L3 P/+ Discontinuity
D3
P/+ T/L3 Continuity
U P/+ Discontinuity
TR1
P/+ U Continuity
V P/+ Discontinuity
TR3
P/+ V Continuity
W P/+ Discontinuity
TR5
P/+ W Continuity
(Assumes the use of an analog meter.)
274
Judgement Level
85% of the initial capacity
Estimated remaining life 10%
Estimated remaining life 10%
(Power ON: 100,000 times left)
Less than 50% of the predetermined speed
Tester Polarity
Measured
Value
R/L1 N/-
D4
N/- R/L1 Discontinuity
S/L2 N/-
D5
N/- S/L2 Discontinuity
T/L3 N/-
D6
N/- T/L3 Discontinuity
U N/-
TR4
N/- U
V N/-
TR6
N/- V
W N/-
TR2
N/- W

. When there is an instantaneous continuity, due to the

. At the time of continuity, the measured value is several to
Measured
Value
Converter module
Continuity
D1 D2
Continuity
R/L1
Continuity
S/L2
Continuity
T/L3
Discontinuity
Continuity
Discontinuity
D4 D5
Continuity
Discontinuity
+ and -, and check for
P/ N/
P/+
Inverter module
TR1 TR3
D3
C
D6
TR4 TR6
N/-
TR5
U
V
W
TR2