ABB RELION REX640 - 4.3.3.6 Current transformer connections and transformation ratio correction

Blocking inputs Description
BLOCK
When active (TRUE), the operation of the function is blocked;
only measurement value outputs are updated.
BLK_OPR_LS
When active (TRUE), TR3PTDF acts normally except that the
OPR_LS output is not active or activated in any circumstan-
ces. Additionally, the OPERATE output can be activated only
by the instantaneous high stage (if not blocked).
BLK_OPR_HS
When active (TRUE), TR3PTDF acts normally except that the
OPR_HS output is not active or activated in any circumstan-
ces. Additionally, the OPERATE output can be activated only
by the biased low stage (if not blocked).
4.3.3.6 Current transformer connections and transformation ratio
correction
The combinations of the connections of the primary current transformers are
designated as "Type 1" and "Type 2". The type needs to be selected separately
for the combination of CT connections on the winding 1 and 2 sides as well as
for the combination of CT connections on the winding 1 and 3 sides in case of
three-winding transformer.
• If the positive directions of the winding 1 and winding 2 relay currents are
opposite, the setting parameter CT connection 1-2 is "Type 1", as shown in Figure
415 .
• If the positive directions of the winding 1 and winding 2 relay currents are equal,
the setting parameter CT connection 1-2 is "Type 2", as shown in Figure 416 .
• 'The default value of the CT connection 1-2 settings is "Type 1".
• The same applies for the CT connection 1-3 settings.
Protection functions
1MRS759142 F
730 REX640
Technical Manual