In an example case of a two-phase short-circuit failure where the fault is between
phases B and C, the angle difference is measured between the polarizing quantity
U
BC
 and operating quantity I
B
 - I
C
 in the self-polarizing method.
GUID-65CFEC0E-0367-44FB-A116-057DD29FEB79 V1 EN
Figure 90: Two-phase short circuit, short circuit is between phases B and C
Cross-polarizing as polarizing quantity
Table 197: Equations for calculating angle difference for cross-polarizing method
Faulte
d
phase
s
Used
fault
current
Used
polarizing
voltage
Angle difference
A I
A
U
BC
ANGLE A U I
BC
A
RCA
o
_ ( ) - ( ) -           = +
ϕ ϕ ϕ
90
GUID-4F0D1491-3679-4B1F-99F7-3704BC15EF9D V3 EN
B I
B
U
CA
ANGLE B U I
CA
B
RCA
o
_ ( ) - ( ) -           = +
ϕ ϕ ϕ
90
GUID-F5252292-E132-41A7-9F6D-C2A3958EE6AD V3 EN
C I
C
U
AB
ANGLE C U I
AB
C
RCA
o
_ ( ) - ( ) -           = +
ϕ ϕ ϕ
90
GUID-84D97257-BAEC-4264-9D93-EC2DF853EAE1 V3 EN
A - B I
A
 - I
B
U
BC
 -
U
CA
ANGLE A U U I I
BC CA
A B
RCA
o
_ ( - ) - ( - ) -                 = +
ϕ ϕ ϕ
90
GUID-AFB15C3F-B9BB-47A2-80E9-796AA1165409 V2 EN
B - C I
B
 - I
C
U
CA
 -
U
AB
ANGLE B U U I I
CA AB
B C
RCA
o
_ ( - ) - ( - ) -                 = +
ϕ ϕ ϕ
90
GUID-C698D9CA-9139-40F2-9097-007B6B14D053 V2 EN
C - A I
C
 - I
A
U
AB
 -
U
BC
ANGLE C U U I I
AB BC
C A
RCA
o
_ ( - ) - ( - ) -                 = +
ϕ ϕ ϕ
90
GUID-838ECE7D-8B1C-466F-8166-E8FE16D28AAD V2 EN
The angle difference between the polarizing quantity U
BC
 and operating quantity
I
A
 is marked as φ in an example of the phasors in a single-phase earth fault where
Section 4 1YHT530004D05 D
Protection functions
186 615 series
Technical Manual