FANOX SIA-B Series, Руководство пользователя

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4.9. Function TB. Trip block protection for the switchgear
This protection function is only available depending on model.
Some transformation centers use a combination of switchgear and fuses for cutting out. As switchgears
have a limited opening current, the fuses are responsible for cutting out the circuit for high current short
circuits. This prevents the switchgear being destroyed if opened in this situation. In order to deal with
these situations, tripping is blocked when the phase current exceeds a pre-set value.
Group Description Minimum Maximum Step Unit Default
TB (*)
Trip block protection for the switchgear
Function Enable - - Yes/No - Yes
Current Tap 1.50 20.00 0.01 x In 7.0
(*) Optional depending on model
4.10. Function 46. Negative sequence inverse time overcurrent.
This protection function is only available depending on model and can be set by using three parameters:
Group Description Minimum Maximum Step Unit Default
46 (*)
Phase balance relay / Negative sequence inverse time overcurrent
Function Enable - - Yes/No/SHB - No
Curve Type - - (1*) - IEC Ext. Inverse
Time Dial (TMS) 0.01 1.5 0.01 - 1.25
Current Tap 0.10 7.00 0.01 x In 1.00
Time Delay 0.02 300.00 0.01 s 0.02
(1*) IEC Inverse, IEC Very Inverse, IEC Extremely Inverse, IEC long time inverse, IEEE Inverse, IEEE
very inverse, IEEE extremely inverse, Defined time
(*) Optional depending on model
If the option
“Defined time” is selected for the curve setting, the unit behaves like an instantaneous
overcurrent unit. In this case, when the Function Enable
is set to “YES”; the accuracy of the Time Delay
is equal to the pre-set time ±30 ms or ±0.5% (whichever is greater). If the Function Enable is set to
“SHB”, the accuracy of the Time Delay is equal to the pre-set time ±50 ms or ±0.5% (whichever is
greater). In this case, the function is activated at 100% of the set tap value, and it deactivates at 95%.
If a curve (inverse, very inverse or extremely inverse) is selected for the curve setting, the trip time
depends on the curve, time dial and current tap settings. When the Function Enable
is set to “YES”; the
accuracy of the trip time is equal to the theoretical trip time ±30 ms or ±5% (whichever is greater). If the
Function Enable is set to “SHB”, the accuracy of the trip time is equal to the theoretical trip time ±50 ms
or ±5% (whichever is greater). In this case, the function is activated at 110% of the set tap value, and it
deactivates at 100%.
Instantaneous reset in both cases.
The curves used are IEC 60255-151 and IEEE, which are described in their section.