FANOX SIA-B Series User Manual

Contents

FANOX SIA-B Series User Manual Manual pdf 20 page image

www.fanox.com Rev. 07 20/1384.2. Function SHB. Second Harmonic BlockingThe second harmonic blocking is used to avoid an undesirable behavior due to inrush current whenenergizing a machine like a transformer or a generator.Group Description Minimum Maximum Step Unit DefaultSHB Second harmonic blockingFunction Enable - - Yes/No - NoCurrent tap 5 50 1 % 5Reset time 0.00 300.00 0.01 s 0.00In order to avoid these undesirable trips, if the second harmonic percentage is higher than the pre-setvalue, the trip will be blocked during the time set in reset time parameter.The function picks-up at 100% off the adjusted input and the dropout is at 95%. The reset type willdepend on the adjusted reset time.The SHB will only be applied in functions that have this option in the “function enable” setting”. Whenthe Function Enable of these protection functions is set to “SHB”, the relay will supervise the the secondharmonic content in order to trip or block the trip depending on the percentage of second harmonicpresent in the current signal.4.3. Function 50. Instantaneous phase overcurrentThis protection function can be set by using three parameters:Function Description Minimum Maximum Step Unit Default50_150_2(*)Instantaneous phase overcurrentFunction Enable - - Yes/No/SHB - NoCurrent Tap 0.07 20.00 0.01 xIn 5.00Time Delay 0.02 300.00 0.01 s 0.2(*) Optional depending on modelThe Time Delay is independent from the operating current flowing through the relay, so if the phasecurrent exceeds its predetermined value for an equal or greater amount of time than this pre-set value,the protection function activates (trips) and does not reset itself until the value of the phase drops belowthe point of current tap.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 TimeDelay is equal to the pre-set time ±50 ms or ±0.5% (whichever is greater).The function activates at 100% of the pre-set input and deactivates at 95%. The reset is instantaneous.