8–2
469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 8: APPENDIX
In the two CT configuration, the currents will sum vectorially at the common point of the
two CTs. The diagram illustrates the two possible configurations. If one phase is reading
high by a factor of 1.73 on a system that is known to be balanced, simply reverse the
polarity of the leads at one of the two phase CTs (taking care that the CTs are still tied to
ground at some point).
Polarity is important
.
To illustrate the point further, the following diagram shows how the current in phases A
and C sum up to create phase 'B'.
808
7
00A1.CDR
A
B
C
A
B
C
:5
:5
:5
:COM
:COM
:COM
808
7
02A1.CDR
1.73
1
1
1
1
60°
60°
60°
808
7
01A1.CDR
1
C
A
B
1.73
1
B
A
C
2-
P
HA
S
E C
T
C
U
RREN
TS
2-
P
HA
S
E C
T
C
U
RREN
TS
180°
O
UT
-
O
F-
P
HA
S
E
Summary of Contents for Masoneilan 469 Series
Page 4: ......
Page 92: ...3 28 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 3 INSTALLATION ...
Page 256: ...5 112 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 5 SETTINGS ...
Page 298: ...6 42 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 6 ACTUAL VALUES ...
Page 321: ...CHAPTER 8 APPENDIX 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL 8 9 808712A1 CDR ...
Page 330: ...8 18 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 8 APPENDIX ...