ABB 615 series Technical Manual page 498

Section 4
Protection functions
492
PCS
BLOCK
87L
UNBLOCK
50-P3
UNBLOCK
50P(2)
50P(1)
51P
PCS
BLOCK
87L
UNBLOCK
50-P3
UNBLOCK
50P(2)
50P(1)
51P
GUID-55C38CA8-1D7D-4CBC-A555-E38B024FF2BA V1 EN
Figure 242: Protection communication supervision detects failures on
communication
In-zone transformer
RED 615
PROTECTED
ZONE
1500A/1
20kV
L
LV
GUID-52FC4852-C9D1-4DD1-B2D7-62FCE98B7FD7 V2 EN
Figure 243: In-zone transformer example about CT ratio correction calculation
The CT ratio correction calculation starts with the rated load current calculation for HV
and LV sides. The rated load current is defined as the rated power of the transformer
Yd11
40MW
110kV
HV
1MAC059074-MB A
RED 615
RED 615
51P
RED 615
50P(1)
50-P3
RED 615
300A/1
~
615 series ANSI
Technical Manual