scheider electric MiCOM P746, Technical Manual

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P746/EN SG/F21 Symbols and Glossary
(SG) 14-
6
MiCOM P746
SG
Symbols Explanation
R Gnd. A distance zone resistive reach setting:
Used for ground (earth) faults.
RBN Lead burden for the neutral.
RBPh Lead burden for the phases.
RCA Abbreviation of “Relay Characteristic Angle”:
The centre of the directional characteristic.
RCT Current Transformer secondary resistance.
REF Restricted earth fault protection.
Rev. Indicates an element responding to a flow in the “reverse” direction.
RMS The equivalent a.c. current:
Taking into account the fundamental, plus the equivalent heating effect of any
harmonics. Abbreviation of “root mean square”.
RP Abbreviation of “Rear Port”:
The communication ports on the rear of the relay.
Rx Abbreviation of “Receive”:
Typically used to indicate a communication receive line/pin.
S1 Used in IEC terminology to identify the secondary CT terminal polarity:
Replace by a dot when using ANSI standards.
S2 Used in IEC terminology to identify the secondary CT terminal polarity:
The non-dot terminal.
SCL Substation Configuration Language:
In IEC 61850, the definition of the configuration files.
SCSM Specific Communication Service Mappings:
In IEC 61850, the SCSMs define the actual information exchange mechanisms
currently used (e.g. MMS).
SDEF Sensitive Differential Earth Fault Protection.
SEF Sensitive Earth Fault Protection.
SSD Solid State Device
T A time delay.
TCS Trip circuit supervision.
TD The time dial multiplier setting:
Applied to inverse-time curves (ANSI/IEEE).
TE A standard for measuring the width of a relay case:
One inch = 5TE units.
TMS The time multiplier setting applied to inverse-time curves (IEC).
Tx Abbreviation of “Transmit”:
Typically used to indicate a communication transmit line/pin.
V Voltage.
V< An undervoltage element.
V<1 First stage of undervoltage protection:
Could be labelled 27-1 in ANSI terminology.