Omron SYSDRIVE MX2 SERIES, User Manual

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11 - 9
11 Maintenance and Inspection
Multi-function Compact Inverter 3G3MX2-V1 User’s Manual (I585-E1)
11
-1 Main
ten
ance a
nd I
n
spe
ctio
n
11
11-1-
8 I/O
V
olt
age/C
urren
t/Electric
P
o
wer Measur
ement Method
Measuring instruments commonly used for input/output voltage, current, or electric power measure-
ment are shown below.
Note 1. For the output voltage, use a measuring instrument that shows effective values of fundamental wave.
For the current and the electric power, use a measuring instrument that shows all effective values.
2. The output waveform of the inverter has a margin of error, especially at low frequencies, because it was
generated under PWM control. Note that many general-purpose testers may not be usable due to noise.
11-1-8 I/O Voltage/Current/Electric Power Measurement Method
Measurement
item
Measurement point Measuring instrument Remarks
Measurement
value reference
Power
supply
voltage
E
IN
Between R/L1 and S/L2 (E
R
)
Between S/L2 and T/L3 (E
R
)
Between T/L3 and R/L1 (E
R
)
Moving-iron voltmeter
or rectifier type voltme-
ter
All
effective
values 200-V class: 200 to 240 V,
50/60 Hz
400-V class: 380 to 480 V,
50/60 Hz
Power
supply
current
I
IN
Current in R/L1, S/L2
T/L3: (I
R
), (I
S
), (I
T
)
Moving iron ammeter
All
effective
values When input current is not
balanced:
I
IN
= (I
R
+
I
S
+
I
T
) / 3
Input
electric
power
W
IN
Between R/L1 and S/L2 (W
I1
)
Between S/L2 and T/L3 (W
I2
)
Between T/L3 and R/L1 (W
I3
)
Electrodynamic watt-
meter
All
effective
values Three-wattmeter method
(W
I1
)
+
(W
I2
)
+
(W
I3
)
Input
power
factor
Pf
IN
Calculate this from the measured values of power supply voltage E
IN
,
power supply current I
IN
, and input electric power W
IN
.
−
Output
voltage
E
OUT
Between U/T1 and V/T2 (E
U
)
Between V/T2 and W/T3 (E
V
)
Between W/T3 and U/T1 (E
W
)
Refer to the figure on
the next page. (Or recti-
fier type voltmeter)
Effective
value of
fundamental
wave
−
Output
current
I
OUT
Current (I
U
), (I
V
), (I
W
) of
U/T1, V/T2, W/T3 Moving iron ammeter
All
effective
values
−
Output
power
W
OUT
Between U/T1 and V/T2 (W
O1
)
Between V/T2 and W/T3 (W
O2
)
Electrodynamic watt-
meter
All
effective
values Two-wattmeter method (or
three-wattmeter method)
(W
O1
)
+
(W
O2
)
Output
power
factor
Pf
OUT
Calculate this from the measured values of output voltage E
OUT
, out-
put current I
OUT
, and output electric power W
OUT
.
−
I
R
I
S
I
T
E
R
E
T
E
S
W
I2
W
I3
W
I1
R
T
S
U
V
W
I
U
I
V
I
W
E
U
E
W
E
V
W
O2
W
O1
W
V
U R
S
T
Inverter
Motor
Power
supply