master:breaker3 parametersPSCAD 3 Phase Breaker

Every parameter of the PSCAD 3 Phase Breaker (master:breaker3): 37 names, with the unit, the default and the meaning PSCAD gives each one. Copy a name into parameters().

What master:breaker3 is

The three phase breaker. Its state at the start of the run is set here; when it opens or closes comes from the logic wired to it, usually a Timed Breaker Logic.

Definition
master:breaker3
PSCAD name
3 Phase Breaker
Category
Faults and switching
Parameters
37, in 5 groups; 11 carry a unit
Read from
PSCAD 5.0.0, 2026-11-07

Most used master:breaker3 parameters

ParameterUnitDescription
RONohmBreaker Closed Resistanceclosed resistance
ROFFohmBreaker Open Resistanceopen resistance
BOpen1·Breaker A statestate of pole A at the start
NAME·Breaker Namethe name of its control signal

Read and write master:breaker3 in Python

import mhi.pscad

pscad = mhi.pscad.connect()              # the PSCAD that is open; launch() starts one
project = pscad.project("my_case")       # a case loaded in the workspace

for comp in project.find_all("master:breaker3"):   # the exact definition, namespace first
    params = comp.parameters()           # every parameter, as PSCAD holds it
    print(str(params["RON"]))            # Breaker Closed  Resistance, in ohm

comp = project.find_all("master:breaker3")[0]
comp.parameters(RON="0.01 [ohm]")        # a value that carries a unit is written with it
  • A parameter is named exactly as in the table, letter case included: parameters() gives every one of them in a dictionary, and a name the component does not have is refused.
  • A value that carries a unit comes back as a number whose unit is only in its text, so read it as text first (str(...)) or the unit is lost. PSCAD keeps a written unit as it is given: "2500 [mohm]" stays in mohm.
  • A Choice is read and written as its symbol (the capitals in "Written as"), not as the words PSCAD shows in the dialog.
  • find_all() takes the exact definition only. A wildcard or a bare name without master: comes back empty; the Builder's px_find walks the pages for those.

The Builder's runtime does the same with the unit handled for you: px_get(comp, "RON") and px_set(...), which also records the old value so the case is put back at the end. Getting started shows them.

Animation States

ParameterUnitDefaultDescription
BOpen1Choice·CLOSEBreaker A stateWritten as CLOSE (close), OPEN (open)
BOpen2Choice·CLOSEBreaker B stateWritten as CLOSE (close), OPEN (open)
BOpen3Choice·CLOSEBreaker C stateWritten as CLOSE (close), OPEN (open)
PReal·0.0Active Power
QReal·0.0Reactive Power

Internal Outputs

ParameterUnitDefaultDescription
BPText··Name for Active PowerRange 0 to 0
BQText··Name for Reactive PowerRange 0 to 0
IBR0Text··Name for Calculated Zero Sequence Current [kA]Range 0 to 0
IBRAText··Name for Breaker Current, A [kA]Range 0 to 0
IBRBText··Name for Breaker Current, B [kA]Range 0 to 0
IBRCText··Name for Breaker Current, C [kA]Range 0 to 0
SBRAText··Name for Breaker A StatusRange 0 to 0
SBRBText··Name for Breaker B StatusRange 0 to 0
SBRCText··Name for Breaker C StatusRange 0 to 0
VbrText··Name for Voltage Across BreakersRange 0 to 0

Configuration

ParameterUnitDefaultDescription
CLVLRealkA0.0Current Chopping LimitUsed when OPCUR==0
CtrlChoice·NOSingle Pole OperationSelect Single pole operation or 3 pole operationWritten as NO (No), YES (Yes)
DisPQChoice·NODisplay Power FlowSelect Yes to display power flow if animation is enabled in the projectWritten as NO (No), YES (Yes)
ENABChoice·NOUse Pre-insertion Resistance?Select Yes to No to enable/disable pre-insertion resistanceWritten as NO (No), YES (Yes)
OPCURChoice·NOOpen Possible at any Current?Select Yes to open the breaker at any current, if not breaker will not open until the current is below the chopping limitWritten as NO (No), YES (Yes)
ViewChoice·SINGLE_LINEGraphics DisplayWritten as 3_PHASE (3 phase view), SINGLE_LINE (Single line view)
ViewBChoice·HIGH_VOLTAGEGraphics DisplayWritten as LOW_VOLTAGE (Low Voltage Display), HIGH_VOLTAGE (High Voltage Display)

Breaker Main Data

ParameterUnitDefaultDescription
NAMEReal·BRKBreaker NameRange 0 to 1Used when Ctrl==0
NAMEAReal·BRKABreaker A NameRange 0 to 1Used when Ctrl==1
NAMEBReal·BRKBBreaker B NameRange 0 to 1Used when Ctrl==1
NAMECReal·BRKCBreaker C NameRange 0 to 1Used when Ctrl==1
ROFFRealohm1.0e6Breaker Open ResistanceAt least 1
RONRealohm0.005Breaker Closed ResistanceAt least 0

Pre-Insertion Data

ParameterUnitDefaultDescription
PRERRealohm0.5Pre-insertion ResistanceAt least 0.001
PostInsChoice·AT_NEXT_CURRENT_ZEROPost-insertion removalWritten as AT_NEXT_CURRENT_ZERO (At next current zero), AFTER_SPECIFIED_TIME (After a specified time)
TDAReals0.0Time Delay for Closing Breaker(A)At least 0
TDBReals0.0Time Delay for Closing Breaker(B)At least 0
TDBOAReals0.005Minimum Time for Post-insertion RemovalAt least 0Used when PostIns
TDCReals0.0Time Delay for Closing Breaker(C)At least 0
TDRAReals0.05Time Delay for Bypassing Pre-Ins.(A)At least 0
TDRBReals0.05Time Delay for Bypassing Pre-Ins.(B)At least 0
TDRCReals0.05Time Delay for Bypassing Pre-Ins.(C)At least 0

Related

← master:wound_rotor Wound Rotor Induction Machine · master:switch Isolation Switch →