Schweitzer Engineering Laboratories SEL-352-1 - Page 70

ii Breaker Logic Date Code 20010731
SEL-352-1, -2 Instruction Manual
Voltage Nulling .......................................................................................................... 3-25
Setting Description .............................................................................................................3-25
Trip Inputs (TRIPA, TRIPB, TRIPC)......................................................................... 3-25
Close Signals (CLOSE, MCLOSE) ............................................................................ 3-25
Breaker Status (52AA, 52AB, 52AC) ........................................................................ 3-25
Phase Overpower (37OP) ........................................................................................... 3-26
Negative-Sequence Overvoltage (47Q)...................................................................... 3-26
Thermal Model Voltage Threshold (87TH) ............................................................... 3-26
Voltage Nulling Delay (VNpu) .................................................................................. 3-26
Maximum Magnitude Nulling (Kmag)....................................................................... 3-27
Maximum Phase Error to Null (Kang) ....................................................................... 3-27
Thermal Logic Enable (THLOG) ............................................................................... 3-27
Overpower Pickup (OPpu).......................................................................................... 3-28
Close Pending Failure (26CP) .................................................................................... 3-28
Close Failure (26CF) .................................................................................................. 3-28
Trip Pending Failure (26TP)....................................................................................... 3-28
Trip Failure (26TF)..................................................................................................... 3-28
Cooling Time Constants (CRTC, TRTC)................................................................... 3-29
Blown Potential Supervision (59L, 27D) ................................................................... 3-29
Setting Calculations............................................................................................................3-29
Thermal Model of Trip and Close Resistors .............................................................. 3-29
Phase Overpower (37OP) ........................................................................................... 3-30
Thermal Model Voltage Threshold (87TH) ............................................................... 3-30
Overpower Pickup (OPpu).......................................................................................... 3-31
Close Resistor Energy................................................................................................. 3-31
Close Pending Failure (26CP) .................................................................................... 3-32
Close Failure (26CF) .................................................................................................. 3-32
Trip Resistor Energy................................................................................................... 3-32
Trip Pending Failure (26TP)....................................................................................... 3-32
Trip Failure (26TF)..................................................................................................... 3-32
Cooling Time Constants (CRTC, TRTC)................................................................... 3-32
Flashover Conditions.................................................................................................................. 3-33
Application Description...................................................................................................... 3-33
Operating Characteristic..................................................................................................... 3-33
Scheme 1 (Flashover, Six Potential Transformers).................................................... 3-33
Scheme 2 (Flashover, Three Potential Transformers)................................................ 3-34
Setting Description .............................................................................................................3-35
Trip Inputs (TRIPA, TRIPB, TRIPC)......................................................................... 3-35
Breaker Close Signal (CLOSE, MCLOSE)................................................................ 3-35
Breaker Status (52AA, 52AB, 52AC) ........................................................................ 3-35
High Set Differential Voltage (87H) .......................................................................... 3-35
Flashover Differential (87FO) .................................................................................... 3-36
Overvoltage (59H/59L) .............................................................................................. 3-36
Flashover Scheme Selection (FOLOG) ...................................................................... 3-37
Flashover Pending Failure (FPpu).............................................................................. 3-37
Flashover Failure (FFpu) ............................................................................................ 3-38
Load Detector (50LD) ................................................................................................ 3-38
Current Unbalance Protection ....................................................................................................3-38
Application Description...................................................................................................... 3-38