CHAPTER 5: SETTINGS GROUPED ELEMENTSM60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 5-1935Figure 5-104: Directional power element sample applicationsDIR POWER 1 RCA — Specifies the relay characteristic angle (RCA) for the sensitive directional power function. Application ofthis setting is threefold:• It allows the element to respond to active or reactive power in any direction (active overpower/underpower, and so on)• Together with a precise calibration angle, it allows compensation for any CT and VT angular errors to permit moresensitive settings• It allows for required direction in situations when the voltage signal is taken from behind a delta-wye connectedpower transformer and the phase angle compensation is requiredFor example, the active overpower characteristic is achieved by setting DIR POWER 1 RCA to “0°,” reactive overpower bysetting DIR POWER 1 RCA to “90°,” active underpower by setting DIR POWER 1 RCA to “180°,” and reactive underpower bysetting DIR POWER 1 RCA to “270°.”DIR POWER 1 CALIBRATION — This setting allows the relay characteristic angle to change in steps of 0.05°. This is usefulwhen a small difference in VT and CT angular errors is to be compensated to permit more sensitive settings. This settingvirtually enables calibration of the directional power function in terms of the angular error of applied VTs and CTs. Theelement responds to the sum of the DIR POWER 1 RCA and DIR POWER 1 CALIBRATION settings.842702A1.CDRPQOPERATERESTRAINRCA = 0oSMIN > 0(d)PQOPERATE RESTRAINRCA = 180oSMIN > 0(a)PQOPERATERESTRAINRCA = 0oSMIN < 0(c)PQOPERATERESTRAINRCA = 180oSMIN < 0(b)PQ OPERATERESTRAINRCA = 90oSMIN > 0(e)PQOPERATERESTRAINRCA = 270oSMIN < 0(f)
