ABB PR512 Manual

Also see for PR512: Operator's manual

1331 2 3Parameters a and b can take on the followingvalues according to the curve selected.• Normal inverse time-delay curve (NI):a = 0.02 b = 0.14.• Very inverse time-delay curve (VI):a = 1 b = 13.5.• Extremely inverse time-delay curve EI):a = 2 b = 80.Selection of t> trip timeThe trip time of the protection is adjusted by usingthe Dip Switches as shown in the figure.By means of the Dip Switches, the value of K is setwhich, when replaced in the previous relation-ships, determines trip time t>.The following settings are possible:• 16 trip times (t>),(K = 0.1...1.6 with steps of 0.1)0.1 0.2 0.3 0.4 0.50.6 0.7 0.8 0.9 1.01.1 1.2 1.3 1.4 1.5 1.6Caption1 Dip Switch for setting the trip threshold of protectionI>2 Dip Switch for setting timing K of protection I>3 Dip Switch for selecting the type of curve forprotection I>:• DT curve with definite time• NI curve with normal inverse time• VI curve with very inverse time• EI curve with extremely inverse time.Protection against instantaneous ordelayed short-circuit (50)This function makes a family of definite adjustabletime curves available, indicated by the symbol I>>.The corresponding trip time is indicated by thesymbol t>>.Start of timing is signalled by the ALARM LEDlighting up, whereas circuit-breaker opening issignalled on the front by the magnetic flag I> I>>,turned to the yellow position. To reset signalling,the FLAG RESET pushbutton on the front of therelease must be pressed, ensuring one of thefollowing conditions:a) 24 Vdc auxiliary voltage present (display lit);b) primary circulating current higher than 0.2 x In(display lit with indication of the circulatingcurrent);c) application of the TT2 unit to the TEST connec-tor on the front of the release (optional acces-sory).Selection of I>> threshold valueSetting the I>> threshold is carried out by workingon the Dip Switches as shown in the figure below.The sum of the values selected represents themultiple of I> and corresponds to threshold I>>.N.B. Even if protection I> is OFF, the first Dip Switchtakes on the value 0.2.The following settings are possible:• 16 threshold current values (I>>)2.5 3.5 4.5 5.57.5 8.5 9.5 10.512 13 14 1517 18 19 20 x I>OFF