ABB RET670 - Description of Configuration B40

TRIP BKR3
94/86
87N
50/51P
87N
27P
59P
50/51G
50/51P
BKR1
60
49
50BF2
50BF1
50BF4
50BF3
VT’s from MV side of XFRM
TRIP BKR1
94/86
TRIP BKR2
94/86
TRIP BKR4
94/86
Trip from 50-BF1,
50-BF2
Trip from 50-BF3,
50-BF4
50/51N
50/51N
BKR2
BKR3
BKR4
CT1
CT2
CT3
CT4
CT6
CT7
WDG1
WDG2
59N
81U
81O
81R
24
87T
50/51G
ANSI10000088-3-en.vsd
ANSI10000088 V3 EN
Figure 329: Protection functions configured in 2 WDG transformer with double
breaker at each winding side
6.2.1.3 Description of configuration B40
This configuration gives complete protection for a three winding transformer with two
breakers on each winding as used on ring bus, or breaker and ½ arrangements. The
tripping is three pole. A provision for Synch check is also provided.
The main protection for the transformer is differential protection. Both the traditional
ampere turn differential, and Kirchoff’s Law based differential protection are available.
Complementing the transformer differential protection is 87N, restricted ground fault
protection, and 87B, bus bar protection.
Section 6 1MRK504116-UUS C
Configuration
858
Application manual