Hitachi SH1-007H

6-4
Chapter 6
Inspection and maintenance
6.5 Checking method for
inverter/converter
・Using the analog multimeter, you can check if the inverter or
converter unit are defective or non-defective.
(Preparation)
① Remove the supply (R,S,T) and motor wiring (U,V,W), and
also the regenerative braking resistor(P,RB).
② Prepare the multimeter. (Application measurement range
is 1Ω)
(Checking method)
・Measure and check the current conduction at each of the
inverter main circuit terminals R, S, T, U, V, W, RB, P, N, by
changing the polarity of the multimeter alternately.
Multimeter polarity
Measured result
(Red)
(Black)
Converter
circuit
D1
R
PD
No conduction
PD
R
Conduction
D2
S
PD
No conduction
PD
S
Conduction
D3
T
PD
No conduction
PD
T
Conduction
D4
R
N
Conduction
N
R
No conduction
D5
S
N
Conduction
N
S
No conduction
D6
T
N
Conduction
N
T
No conduction
Inverter
circuit
TR1
U
P
No conduction
P
U
Conduction
TR2
V
P
No conduction
P
V
Conduction
TR3
W
P
No conduction
P
W
Conduction
TR4
U
N
Conduction
N
U
No conduction
TR5
V
N
Conduction
N
V
No conduction
TR6
W
N
Conduction
N
W
No conduction
BRD part
TR7
RB
P
No conduction
P
RB
Conduction
RB
N
Don't care
N
RB
No conduction
*1) Before checking the circuits, measure the voltage across
terminals P and N with the multimeter in DC bus voltage
range mode to confirm that the smoothing capacitor has
been fully discharged.
*2) When not conducting, it shows an infinite value. Due to the
influence of the smoothing capacitor, it may show
momentarily any other value other than infinite. When the
measured terminal is conductive, the tester reading is
several ohms to several tens of ohms. The measurements
with different multimeters may not match exactly, but as
long the values are close between them, it is acceptable.
*3) The chopper braking circuit is built-in in the models below:
SH1-00041-H to SH1-00930-H
(SH1-007H to SH1-370H ND rated)
Model(SH1-*****-*)
400V class : 00041-H(007H) to 00310-H(110H)
Model(SH1-*****-*)
400V class : 00400-H(150H) to 06600-H(3150H)