ABB Relion REC670, Applications Manual

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Pickup_Curr : Operation phase current level given in % of IBase .
Characterist : Selection of time characteristic: Definite time delay and different types
of inverse time characteristics are available; see Technical Manual for details.
tDef_OC : Definite time delay. It is used if definite time characteristic is chosen; it shall
be set to 0 s if the inverse time characteristic is chosen and no additional delay shall be
added. Note that the value set is the time between activation of the start and the trip
outputs.
k : Time multiplier for inverse time delay.
tMin : Minimum operation time for all inverse time characteristics. At high currents the
inverse time characteristic might give a very short operation time. By setting this
parameter the operation time of the step can never be shorter than the setting.
Operation_UV : it sets On / Off the operation of the under-voltage stage.
PickUp_Volt : Operation phase-to-phase voltage level given in % of VBase for the
under-voltage stage. Typical setting may be, for example, in the range from 70% to
80% of the rated voltage of the generator.
tDef_UV : Definite time delay. Since it is related to a backup protection function, a long
time delay (for example 0.5 s or more) is typically used. Note that the value set is the
time between activation of the start and the trip outputs.
EnBlkLowV : This parameter enables the internal block of the undervoltage stage for
low voltage condition; the voltage level is defined by the parameter BlkLowVolt .
BlkLowVolt : Voltage level under which the internal blocking of the undervoltage stage
is activated; it is set in % of VBase . This setting must be lower than the setting
StartVolt . The setting can be very low, for example, lower than 10%.
VDepMode : Selection of the characteristic of the start level of the overcurrent stage as
a function of the phase-to-phase voltage; two options are available: Slope and Step. See
Technical Manual for details about the characteristics.
VDepFact : Slope mode : it is the pickup level of the overcurrent stage given in % of
Pickup_Curr when the voltage is lower than 25% of VBase ; so it defines the first point
of the characteristic ( VDepFact * Pickup_Curr /100* IBase ; 0.25* VBase ).
Step mode : it is the pickup level of the overcurrent stage given in % of Pickup_Curr
when the voltage is lower than VHighLimit /100* VBase .
VHighLimit : when the measured phase-to-phase voltage is higher than VHighLimit /
100* VBase , than the pickup level of the overcurrent stage is Pickup_Curr /100* IBase .
In particular, in Slope mode it define the second point of the characteristic
( Pickup_Curr /100* IBase ; VHighLimit /100* VBase ).
Section 8
1MRK 511 401-UUS A
Current protection
238 Bay control REC670 2.2 ANSI
Application manual