CHAPTER 6: ACTUAL VALUES
469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUAL
6–21
Pressing the “View” button displays the following screen:
The following phasor diagram illustrates the vector diagram of our example. By definition,
power factor is the cosine of the angle between the phase to neutral voltages and the
corresponding phase current. In this example, 18.2° is the angle between Van and Ia, Vbn
and Ib, and Vcn and Ic. Since the relay is measuring phase-phase quantities, and Vab is the
reference phasor, the angle displayed by the relay takes into consideration the 30° angle
between phase-phase and phase-neutral voltages.
FIGURE 6–7: Phasor Diagram for Open Delta Example
Table 6–1: Three-phase Open Delta VT Connection
ABC
Rotation
0.3 pf (72.5°)
lag
0.7 pf
(45°) lag
1.00 pf
(0°) lag
0.7 pf
(45°) lead
0.3 pf (72.5°)
lead
Va
0
0
°
0
°
0
°
0
806559A1.CDR
Phase
R
otat
i
on
Van
–
Vbc
Vca
I
b
Vbn
I
a
I
c
Vcn
Vbc
Vab
S
ystem Voltages:
Vab
Vbc
Vca
Measured Voltages:
Vab
=
V
A
(G
2 –
G
1
)
–
Vbc
=
V
C
(
H2 –
G
1
)
Calculated Voltage:
Vac
=
Vab
+
Vbc
Displayed Voltages:
Va
=
Vab
Vb
= 0°
Vc
= –
Vbc
Summary of Contents for 469
Page 62: ...2 16 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 2 INTRODUCTION ...
Page 90: ...3 28 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 3 INSTALLATION ...
Page 292: ...6 42 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 6 ACTUAL VALUES ...
Page 313: ...A APPENDIX 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL A 7 HGF5C 808841A1 HGF8 808842A1 ...
Page 315: ...A APPENDIX 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL A 9 808712A1 CDR ...
Page 320: ...A 14 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL A APPENDIX ...