YOKOGAWA CW240 User Manual

17-5
IM CW240E
CW 240 Specifications
17
Measurement
Item
Wiring
3 Phase 3 Wire
3 Current
3 Phase 4 Wire
Average Voltage
Uave
(U
1 U2  U3) / 2
*2
I Iave ( I 1
 I 2  I 3 ) / 3
*3
∑P
P
1 P2  P3
*5
∑Q
Q1
 Q2  Q3
*5
Average Current
Active Power
Reactive Power 2
*4
Apparent Power
S
 U  I ∑S
Power Factor
Reactive power
method not used
*6
∑PF
Reactive power
method used
∑PF
Phase Angle
*6
∑PA
∑ PF =
S 1 S2  S3
*5
∑ S
∑ P
Q = S
2
 P
2
∑ P
2
 ∑ Q
2
∑ PF =
∑ PA = cos
–1
∑ PF
∑ P
*1: In the case of distorted wave input, there may be a difference with other measuring devices
that use a different measurement principle.
*2: Line voltage for 3 phase 3 wire, and phase voltage for 3 phase 4 wire.
*3:
I2 for 3 phase 3 wire (2 power-meter method) is the result calculated through vector operation.
*4: When not using the reactive power method. Even in this case, the operation is performed by
multiplying the polarity of Q of each phase calculated with the reactive power method.
*5: For 3 phase 3 wire, the voltage used when obtaining the electric power of each phase is the
phase voltage from the virtual neutral point.
*6: The operation is performed by multiplying the polarity of Q of each phase calculated with the
reactive power method.
*7: In the case of unbalanced input with 3 phase 3 wire (2 power-meter method), there may be
a difference with other connections or measuring devices that use a different measurement
principle.
P1, P3, Q1, Q3, S1, S3, PF1, and PF3 have not physical meaning as values in the operation
process of the 2 power-meter method.
Equations Symbol
_
_
_
_
TIP
The active power, reactive power, apparent power, power factor, and phase angle
measure the value of each phase.
17.1 CW 240 Specifications

YOKOGAWA CW240 Specifications

General

Brand	YOKOGAWA
Model	CW240
Category	Measuring Instruments
Language	English