ABB RELION RET670, Applications Manual

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Section 3 Configuration
3.1 Description of configuration RET670
IP14806-1 v2
3.1.1 Introduction
IP14807-1 v2
The RET 670 comes preconfigured for several applications.
ANSI RET670 Configurations Description
RET670-A30 Single breaker, two winding transformer
RET670-b30 Double breaker, two winding transformer
RET670-B40 Double breaker, three winding transformer
Each of these configurations will be described below.
3.1.1.1 Description of configuration A10
GUID-FFF089C9-987F-4D6B-A3C5-B0A7B480AE21 v5
The configuration of the IED is shown in Figure 2 .
This configuration is used in applications with two- or three- winding transformers
with single or double busbars and with a single or multi-breaker arrangements. The
protection scheme includes a 3–phase tripping scheme with a synchronism check
function for manual closing of the low voltage side breaker.
The high voltage breaker is foreseen to always energize the transformer and be
interlocked with an open LV side breaker.
The tripping from transformer auxiliaries such as buchholtz, temperature devices are
linked through the binary inputs which are stabilized against unnecessary operations
due to capacitive discharges. It can be done in this back-up IED to have it independent
from the main protection IED where differential functions are provided.
Back-up protection for faults inside the transformer but mainly for system faults are
provided by the phase and ground overcurrent functions provided for each of the
windings. If only a two winding transformer exists the neutral currents can be
connected to the ground fault functions instead of the default bay residual currents.
1MRK 504 163-UUS A
Section 3
Configuration
Transformer protection RET670 2.2 ANSI 59
Application manual