Section 2 Available functions2.1 Main protection functionsIEC 61850 orFunction nameANSI Function description TransformerRET650RET650 (A01)2W/1CBRET650 (A05)3W/1CBRET650 (A07)OLTCDifferential protectionT2WPDIF 87T Transformer differential protection, two winding 0–1 1T3WPDIF 87T Transformer differential protection, three winding 0–1 1REFPDIF 87N Restricted earth fault protection, low impedance 0–3 2 3HZPDIF 87 1Ph High impedance differential protection 0–2 2 2Impedance protectionZMRPSB 68 Power swing detection 0–1ZGCPDIS 21G Underimpedance protection for generators andtransformers0–1LEPDIS Load encroachment 0–12.2 Back-up protection functionsIEC 61850 orFunction nameANSI Function description TransformerRET650RET650 (A01)2W/1CBRET650 (A05)3W/1CBRET650 (A07)OLTCCurrent protectionPHPIOC 50 Instantaneous phase overcurrent protection, 3–phase output0–3 2 3OC4PTOC 51/67 Four step phase overcurrent protection, 3-phaseoutput0–3 2 3 2EFPIOC 50N Instantaneous residual overcurrent protection 0–3 2 3EF4PTOC 51N/67N Four step residual overcurrent protection, zero/negative sequence direction0–3 2 3 2TRPTTR 49 Thermal overload protection, two time constants 0–3 2 3 2Table continues on next page1MRK 504 135-UEN A Section 2Available functions35Technical manual
