settable for step 1 and can be either definite or inverse time delayed. Step 2 is alwaysdefinite time delayed.UV2PTUV (27) can be set to measure phase-to-ground fundamental value, phase-to-phase fundamental value, phase-to-ground true RMS value or phase-to-phase trueRMS value. The choice of the measuring is done by the parameter ConnType. Thevoltage related settings are made in percent of base voltage which is set in kV phase-to-phase voltage. This means operation for phase-to-ground voltage under:(%) ( )3Vpickup VBase kV< ×EQUATION1606 V1 EN (Equation 69)and operation for phase-to-phase voltage under:Vpickup (%) VBase(kV)< ×EQUATION1991-ANSI V1 EN (Equation 70)When phase-to-ground voltage measurement is selected the functionautomatically introduces division of the base value by the square rootof three.9.1.7.1 Measurement principleDepending on the set ConnType value, UV2PTUV (27) measures phase-to-ground orphase-to-phase voltages and compare against set values, Pickup1 and Pickup2. Theparameters OpMode1 and OpMode2 influence the requirements to activate thePICKUP outputs. Either 1 out of 3, 2 out of 3, or 3 out of 3 measured voltages have tobe lower than the corresponding set point to issue the corresponding PICKUP signal.To avoid oscillations of the output PICKUP signal, a hysteresis has been included.9.1.7.2 Time delayThe time delay for step 1 can be either definite time delay (DT) or inverse timeundervoltage (TUV). Step 2 is always definite time delay (DT). For the inverse timedelay two different modes are available; inverse curve A and inverse curve B.The type A curve is described as:Section 9 1MRK 502 043-UUS BVoltage protection254Technical Manual
