Ice NP900 Series, Инструкция по применению

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Application Guide - NP900 Series 66 (504
)
A996A
Table 3.2.3.1-51 Analogic magnitudes used by the NEF function.
Signal Description Time base
I01PP Peak-to-peak measurement of coarse residual current
measurement input I01 5 ms
I01RMS Fundamental RMS measurement of coarse residual current
measurement input I01 5 ms
I01TRMS TRMS measurement of coarse residual current
measurement input I01 5 ms
I02PP Peak-to-peak measurement of sensitive residual current
measurement input I02 5 ms
I02RMS Fundamental RMS measurement of sensitive residual
current measurement input I02 5 ms
I02TRMS TRMS measurement of coarse sensitive current
measurement input I02 5 ms
I0Calc Fundamental RMS value of the calculated zero sequence
current from the three phase currents 5 ms
Selection of the used AI channel is made with a setting parameter. In all possible input
channel variations pre-fault condition is presented with 20 ms averaged history value from
-20 ms of Start or Trip event.
3.2.3.2 P
ICK
-
UP CHARACTERISTICS
Pick-up of the NEF function is controlled by
I0set
setting parameter, which defines 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 3.2.3.2-52 Pick-up characteristics setting
Name Description Range Step Default
I0set Pick-up setting 0.005 … 40.00 x In 0.001 x In 1.20 x In
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.