ABB Relion 670 Series Technical Reference Manual page 747

1MRK 505 208-UEN B
Technical reference manual
IRIG-B: InterRange Instrumentation Group Time code format B,
standard 200
ITU International Telecommunications Union
LAN Local area network
LIB 520 High-voltage software module
LCD Liquid crystal display
LDCM Line differential communication module
LDD Local detection device
LED Light-emitting diode
LNT LON network tool
LON Local operating network
MCB Miniature circuit breaker
MCM Mezzanine carrier module
MIM Milli-ampere module
MPM Main processing module
MVB Multifunction vehicle bus. Standardized serial bus originally
developed for use in trains.
NCC National Control Centre
NUM Numerical module
OCO cycle Open-close-open cycle
OCP Overcurrent protection
OEM Optical ethernet module
OLTC On-load tap changer
OV Over-voltage
Overreach A term used to describe how the relay behaves during a fault
condition. For example, a distance relay is overreaching
when the impedance presented to it is smaller than the
apparent impedance to the fault applied to the balance point,
that is, the set reach. The relay "sees" the fault but perhaps it
should not have seen it.
PCI Peripheral component interconnect, a local data bus
PCM Pulse code modulation
PCM600 Protection and control IED manager
PC-MIP Mezzanine card standard
PISA Process interface for sensors & actuators
PMC PCI Mezzanine card
Section 21
Glossary
741