9.3.4.5
Four step residual overcurrent protection (PEFM, 51N/67N)
Settings/Setting Group N/Current protection/
ResidualOverCurrent4Step(PEFM)
Displays three instances of TEF with a large number of settings per instance. Typical
settings are those for harmonic restraint, minimum fundamental frequency current
level, base settings for current and voltage and several others.
9.3.4.6
Thermal overload protection, two time constants (PTTR, 49)
Settings/Setting Group N/Current protection/
TermalOverload2TimeConst(PTTR)
Displays three instances of TTR with 23 settable parameters per instance. Typical
settings are length of pulse for trip signal, reference current as a percentage of the
base system current and several other related settings.
9.3.4.7
Breaker failure protection (RBRF, 50BF)
Settings/Setting Group N/Current protection/BreakerFailure(RBRF)
Displays 6 instances of BFP with 14 settings per instance. Settings include operation,
base current, function mode, operation mode of retrip logic, time delays and several
others.
9.3.4.8
Pole discordance protection (RPLD, 52PD)
Settings/Setting Group N/Current protection/PoleDiscordance(RPLD)
Displays two instances of PD with seven settings per instance. The settings are for
operation, base current, trip time delay, contact function selection, current function
selection, asymmetrical magnitude of current and current release threshold.
9.3.5
Voltage protection
9.3.5.1
Overview
For Voltage protection there are settings for Under-voltage, Over-voltage, Residual
over-voltage and Overexcitation protection. There are three instances of parameters
in each category except in the case of Overexcitation which has two instances. Each
instance consists of a number of parameters that make it possible to switch the
function On or Off, set rated quantities or make other adjustments necessary for the
fine tuning of the function itself.
9.3.5.2
Two step undervoltage protection (PUVM, 27)
Settings/Setting Group N/Voltage protection/UnderVoltage2Step(PUVM)
Section 9
Read and change settings
48
Operator's manual
1MRK504049-UEN rev. D
RET 670