Omron 3G3RX Series, User Manual

Page: 346 / 442

6-9
6-1 Inspection and Maintenance
6
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.
Power
supply
R
S
T
I
R
I
S
I
T
E
R
E
S
E
T
W
11
W
12
W
13
R/L1
S/L2
T/L3
U/T1
V/T2
W/T3
In
v
er
ter
I
U
I
V
I
W
E
U
E
V
E
W
W
01
W
02
U
V
W
Motor
Measurement
item
Measurement point Measurement device Note Measurement value reference
Power
supply
voltage
E
IN
Between R-S, S-T, and T-
R
(E
R
), (E
S
), (E
T
)
Moving-iron voltmeter
or
Rectifier voltmeter
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 R, S, T
(I
R
), (I
S
), (I
T
)
Moving iron ammeter
All
effective
values When the input current is not
balanced
I
IN
= (I
R
+I
S
+ I
T
)/3
Input
electric
power
W
IN
Between R-S, S-T, and
T-R
(W
I1
) + (W
I2
) + (W
I3
)
Electrodynamic
wattmeter
All
effective
values
Three-wattmeter method
Input
power
factor 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
E
OUT
Between U-V, V-W, W-U
(E
U
), (E
V
), (E
W
)
See the figure below
or
Rectifier voltmeter
Effective
value of
fundamental
wave
Output
current
I
OUT
Current U, V, W
(I
U
), (I
V
),(I
W
)
Moving iron ammeter
All
effective
values
Output
power
W
OUT
Between U-V, V-W
(W
O1
)+(W
O2
)
Electrodynamic
wattmeter
All
effective
values
Two-wattmeter method
(or three-wattmeter method)
Output
power
factor
Pf
OUT
Calculated from the measured values of output voltage E
OUT
,
output current I
OUT
, and output power W
OUT
.
Pf
IN
=
3
⋅
E
IN
⋅
I
IN
W
IN
× 100(%)
Pf
OUT
=
3
⋅
E
OUT
⋅
I
OUT
W
OUT
× 100(%)