Hitachi WJ C1 Series User Manual

Chapter 16 Maintenance and Inspection
16-2-4
16.2.4 Checking the Inverter and Converter Section
Checking method of inverter and converter
Using the analog multimeter, it can be checked if the inverter or converter unit are defective or non-defective.
1 Preparation
(1) Disconnect all wires to the main circuit terminal block (wires to the [R/L1], [S/L2], [T/L3],
[U/T1], [V/T2], [W/T3], [P/+], [PD/+1], [N/-], and [RB] terminals).
(2) Prepare an analog multimeter. (The use range is 1 Ω resistance measurement range.)
2 Checking method
The good-or-bad condition of conduction status of terminals on the inverter main circuit
terminal block [R/L1], [S/L2], [T/L3], [U/T1], [V/T2], [W/T3], [P/+], [PD/+1], [N/-] and [RB]
can be judged by alternately changing the polarity of tester for measurement.
 By measuring the voltage between P and N in the DC voltage range, check that
electricity is fully discharged from the smoothing capacitor before performing check.
 When electricity is not conducted, the value is almost infinite. (When conducting, it
indicates several ohms to several tens of ohms.)
Due to effects of the smoothing capacitor, electricity may be conducted instantly and
may not show infinity value. The measured values vary depending on the element type,
tester type, etc., but it is acceptable if the values in each section are nearly equal. The
measured value may be shifted by several ohms due to the current limiting resistance for
preventing inrush current.
Tester polarity
Measured value
(Red)
(black)
Converter
D1
R/L1
PD/+
Non-conductive
PD/+
R/L1
Conductive
D2
S/L2
PD/+
Non-conductive
PD/+
S/L2
Conductive
D3
T/L3
PD/+
Non-conductive
PD/+
T/L3
Conductive
D4
R/L1
N/-
Conductive
N/-
R/L1
Non-conductive
D5
S/L2
N/-
Conductive
N/-
S/L2
Non-conductive
D6
T/L3
N/-
Conductive
N/-
T/L3
Non-conductive
Inverter
TR1
U/T1
P/+
Non-conductive
P/+
U/T1
Conductive
TR2
V/T2
P/+
Non-conductive
P/+
V/T2
Conductive
TR3
W/T3
P/+
Non-conductive
P/+
W/T3
Conductive
TR4
U/T1
N/-
Conductive
N/-
U/T1
Non-conductive
TR5
V/T2
N/-
Conductive
N/-
V/T2
Non-conductive
TR6
W/T3
N/-
Conductive
N/-
W/T3
Non-conductive
BRD
TR7
RB
P/+
Non-conductive
P/+
RB
Conductive
RB
N/-
Uncertainty
N/-
RB
Non-conductive
▼
Converter
Inverter
PD/+1
D1
D4
D2
D5
D3
D6
R/L1
S/L2
T/L3
TR4
TR5
TR6
TR1
TR2
TR3
C +
P/+
N/-
TR7
RB
U/T1
V/T2
W/T3
Chopper braking circuit (BRD)

Hitachi WJ C1 Series Specifications

General

Brand	Hitachi
Model	WJ C1 Series
Category	Inverter
Language	English