ABB RET615 Product Manual page 10

Transformer Protection and Control
RET615
Product version: 2.0
Figure 5. Main protection of a Yyn(d) connected power transformer and control of the HV side
circuit breaker using a RET615 with the standard configuration D. Restricted E/F
protection with a high impedance scheme is applied on the transformer MV side. A
REF615 with the standard configuration C is used as redundant back-up protection
on the HV side. In addition, a REF615 with the standard configuration F is used on
the MV side to provide, besides O/C and E/F back-up protection, busbar overvoltage
and undervoltage protection. Further, the REF615 with the standard configuration F
enables local/remote control of the circuit breaker on the MV side.
10
GUID-AB31C909-F38E-4885-AFEE-E2EEE3675263 V1 EN
1MRS756891 B
Issued: 01.10.2009
ABB