entered as a setting parameter for the pre-processing block, which will then take
automatic care about it.
The user can select one of the current quantities shown in table 299 for built-in current
restraint feature:
Table 299: Restraint current selection for CVGAPC function
Set value for the
parameter
RestrCurr
Comment
1 PosSeq CVGAPC function will measure internally calculated positive sequence
current phasor
2 NegSeq CVGAPC function will measure internally calculated negative sequence
current phasor
3 3ZeroSeq CVGAPC function will measure internally calculated zero sequence current
phasor multiplied by factor 3
4 MaxPh CVGAPC function will measure current phasor of the phase with maximum
magnitude
10.1.2.2 Base quantities for CVGAPC function
The parameter settings for the base quantities, which represent the base (100%) for
pickup levels of all measuring stages, shall be entered as setting parameters for every
CVGAPC function.
Base current shall be entered as:
1. rated phase current of the protected object in primary amperes, when the measured
Current Quantity is selected from 1 to 9, as shown in table
297.
2. rated phase current of the protected object in primary amperes multiplied by √3
(1.732 · Iphase), when the measured Current Quantity is selected from 10 to 15, as
shown in table
297.
Base voltage shall be entered as:
1. rated phase-to-ground voltage of the protected object in primary kV, when the
measured Voltage Quantity is selected from 1 to 9, as shown in table 298.
2. rated phase-to-phase voltage of the protected object in primary kV, when the
measured Voltage Quantity is selected from 10 to 15, as shown in table 298.
10.1.2.3 Built-in overcurrent protection steps
Two overcurrent protection steps are available. They are absolutely identical and
therefore only one will be explained here.
Section 10 1MRK505222-UUS C
Multipurpose protection
570
Technical reference manual
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