Omron SYSDRIVE MX2 SERIES - Measurement Methods of I;O Voltage, Current, and Electric Power

8-8
8-1 Inspection and Maintenance
SYSDRIVE MX2 Series USER'S MANUAL (3G3MX2-Axxxx)
8
Inspection and Maintenance
Measurement Methods of I/O Voltage, Current, and Electric Power
Below is a general measurement device for input/output voltages, current, and electric power.
I R
I S
I T
ER
ET
ES
WI2
WI3
WI1
R
T
S
U
V
W
I U
I V
I W
EU
EW
EV
WO2
WO1
Motor
W
V
U R
S
T
Power
supply
Inverter
Measurement
item
Measurement point Measurement device Note
Measurement value
reference
Power
supply
voltage
E
IN
Between R/L1 and S/
L2 (ER)
Between S/L2 and T/
L3 (E
S)
Between T/L3 and R/
L1(E
T)
Moving iron
voltmeter or
commutating
voltmeter
All
effective
values
200 V class: 200 to 240 V,
50/60Hz
400 V class: 380 to 480 V,
50/60Hz
Power
supply
current
I
IN
Current of R/L1, S/L2,
T/L3
(I
R),(IS),(IT)
Moving iron
ammeter
All
effective
values
When the input current is
not balanced
I
IN = (IR + IS + IT)/3
Input electric
power
WIN
Between R/L1 and S/
L2 (WI1)
Between S/L2 and T/
L3 (W
I2)
Between T/L3 and R/
L1(WI3)
Electrodynamic
wattmeter
All
effective
values
Three-wattmeter method
(W
I1) + (WI2) + (WI3)
Power factor
of power
supply
Pf
IN
Calculated from the measured values of power supply voltage
E
IN , power supply current I IN , and input electric power W IN .
−
Output
voltage
EOUT
Between U/T1 and V/
T2 (EU)
Between V/T2 and W/
T3 (E
V)
Between W/T3 and U/
T1 (EW)
Refer to the figure
on the next page,
or commutating
voltmeter
Fundam
ental
wave
Effective
value
−
Output current
IOUT
Current of U/T1, V/T2,
W/T3
(I
U),(IV),(IW)
Moving iron
ammeter
All
effective
values
−
Output power
WOUT
Between U/T1 and V/
T2 (W
O1)
Between V/T2 and W/
T3 (W
O2)
Electrodynamic
wattmeter
All
effective
values
Two-wattmeter method
(or three-wattmeter
method)
(WO1) + (WO2)
PfIN =
W
IN
3 · EIN · IIN
× 100 (%)