GE P741 Technical Manual page 506

Symbols and Glossary
MiCOM P741, P742, P743
Symbols
MCB A "miniature circuit breaker":
Used instead of a fuse to protect VT secondary circuits.
Model Implementation Conformance Specification:
MICS
Defines the IEC 61850 data model implemented in an IED.
Manufacturing Message Specification:
MMS
A protocol used to transport the data of IEC 61850 across an Ethernet network.
N Indication of "Neutral" involvement in a fault:
i.e. a ground (earth) fault.
N/A
Not applicable.
N/C A normally closed or "break" contact:
Often called a "form B" contact.
N/O A normally open or "make" contact:
Often called a "form A" contact.
Network Interface Card:
NIC
i.e. the Ethernet card of the IED
NPS Negative phase sequence.
NVD Neutral voltage displacement:
Equivalent to residual overvoltage protection.
NXT Abbreviation of "Next":
In connection with hotkey menu navigation.
A small circle on the input or output of a logic gate:
o
Indicates a NOT (invert) function.
O/P Abbreviation of "output".
Opto An optocoupled logic input:
Alternative terminology: binary input.
P1 Used in IEC terminology to identify the primary CT terminal polarity:
Replace by a dot when using ANSI standards.
P2 Used in IEC terminology to identify the primary CT terminal polarity:
The non-dot terminal.
PCB
Printed circuit board.
Ph Abbreviation of "Phase":
Used in distance settings to identify settings that relate to phase-phase faults.
PICS Protocol Implementation Conformance Specification:
Defines the IEC 61850 services implemented in an IED, with reference to the ACSI.
PN> Wattmetric earth fault protection:
Calculated using residual voltage and current quantities.
Pol Abbreviation of "Polarizing":
Typically the polarizing voltage used in making directional decisions.
PSL Programmable scheme logic:
The part of the relay's logic configuration that can be modified by the user, using the
graphical editor within S1 software.
PU
Abbreviation of "Peripheral Unit" (P742 or P743)
Qx Isolator number x (from 1 to 6).
Explanation
P74x/EN SG/Na7
(SG) 14-5
SG