Omron RX User Manual page 338

6-1 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.
R
S
Power
supply
T
Measurement
item
Power
Between R-S, S-T, and T-
supply
R
voltage
6
(E ), (E
R
E
IN
Power
supply Current R, S, T
current (I ), (I
R
I
IN
Input
Between R-S, S-T, and
electric
T-R
power
(W
I1
W
IN
Calculated from the measured values of power supply voltage
Input E , power supply current I
IN
power
factor Pf
IN
Output
Between U-V, V-W, W-U
voltage
(E ), (E
U
E
OUT
Output
Current U, V, W
current
(I ), (I
U
I
OUT
Output
Between U-V, V-W
power
(W
O1
W
OUT
Output
Calculated from the measured values of output voltage E
power
output current I
factor
Pf
OUT
6-9
W
I
11
R
E
R
I
W
S
12
E
S
I W
T 13
E
T
Measurement point Measurement device
Moving-iron voltmeter
), (E )
S T
Moving iron ammeter
), (I )
S T
) + (W ) + (W )
I2 I3
, and input electric power W
IN
W
IN
Pf =
IN
3 ⋅ E
IN
), (E )
V W
Moving iron ammeter
),(I )
V W
)+(W )
O2
, and output power W
OUT
W
OUT
Pf =
OUT
3 ⋅ E
OUT
R/L1 U/T1
I
U
S/L2 I
V/T2
V
T/L3
W/T3 I
W
Note
All
or effective
Rectifier voltmeter values
All
effective
values
All
Electrodynamic
effective
wattmeter
values
.
IN
× 100(%)
⋅ I
IN
Effective
See the figure below
value of
or
fundamental
Rectifier voltmeter
wave
All
effective
values
All
Electrodynamic
effective
wattmeter
values
,
OUT
.
OUT
× 100(%)
⋅ I
OUT
U
W
01
E
U
V
Motor
E
V
W
W
02
E
W
Measurement value reference
200-V class: 200 to 240 V, 50/60 Hz
400-V class: 380 to 480 V, 50/60 Hz
When the input current is not
balanced
I = (I +I + I )/3
IN R S T
Three-wattmeter method
Two-wattmeter method
(or three-wattmeter method)