Arcteq AQ-T257, Instruction Manual

Page: 45 / 359

General settings
The following general settings de ne the general behavior of the function. These settings are static i.e.
it is not possible change them with setting group switching.
Table. 5.4.1. - 50. General settings of the function
Name Description Range Step Default
Setting control from
comm bus
Activating this parameter permits changing the pick-up level of the
protection stage via SCADA.
1:Disabled
2:Allowed
- 1:Disabled
Measured magnitude
De nes which available measured magnitude is used by the
function.
1:RMS
2:TRMS
3:Peak-to-
peak
- 1:RMS
Meas side
De nes which current measurement module is used by the
function.
1:Side1
2:Side2
- 1:Side1
Pick-up characteristics
Pick-up of the NOC function is controlled by Iset setting parameter, which de nes the maximum
allowed measured current before action from the function. The function constantly calculates the ratio
in between of the Iset and measured magnitude (Im) per all three phases. Reset ratio of 97 % is inbuilt
in the function and is always related to the Iset value. The setting value is common for all measured
phases and single-, dual- or all phases Im exceed of the Iset value will cause pick-up operation of the
function.
Table. 5.4.1. - 51. Pick-up characteristics setting
Name Description Range Step Default
Iset Pick-up setting 0.10 … 50.00xIn 0.01xIn 1.20xIn
The pick-up activation of the function is not directly equal to start-signal generation of the function.
Start signal is allowed if blocking condition is not active.
Function blocking
In the blocking element the block signal is checked in the beginning of each program cycle. Blocking
signal is received from the blocking matrix for the function dedicated input. Additionally, non-directional
overcurrent protection includes internal inrush harmonic blocking option which is applied by user set
parameter. If the blocking signal is not activated when the pick-up element activates, a START signal is
generated and the function proceeds to the time characteristics calculation.
Table. 5.4.1. - 52. Internal inrush harmonic blocking settings
Name Description Range Step Default
Inrush Harmonic Blocking (Internal
Only Trip)
2
nd
harmonic blocking
enable/disable
0;No
1;Yes
- No
2
nd
Harmonic Block Limit (Iharm/Ifund) 2
nd
harmonic blocking limit.
0.10…
50.00*%Ifund
0.01*%Ifund 0.01*%Ifund
AQ-T257
Instruction manual
Version: 2.00
© Arcteq Relays Ltd 44