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
Parameter
Unit
Description
RON
ohm
Breaker Closed Resistanceclosed resistance
ROFF
ohm
Breaker 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 workspacefor comp in project.find_all("master:breaker3"): # the exact definition, namespace first
params = comp.parameters() # every parameter, as PSCAD holds itprint(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.
Breaker A stateWritten as CLOSE (close), OPEN (open)
BOpen2Choice
·
CLOSE
Breaker B stateWritten as CLOSE (close), OPEN (open)
BOpen3Choice
·
CLOSE
Breaker C stateWritten as CLOSE (close), OPEN (open)
PReal
·
0.0
Active Power
QReal
·
0.0
Reactive Power
Internal Outputs
Parameter
Unit
Default
Description
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
Parameter
Unit
Default
Description
CLVLReal
kA
0.0
Current Chopping LimitUsed when OPCUR==0
CtrlChoice
·
NO
Single Pole OperationSelect Single pole operation or 3 pole operationWritten as NO (No), YES (Yes)
DisPQChoice
·
NO
Display Power FlowSelect Yes to display power flow if animation is enabled in the projectWritten as NO (No), YES (Yes)
ENABChoice
·
NO
Use Pre-insertion Resistance?Select Yes to No to enable/disable pre-insertion resistanceWritten as NO (No), YES (Yes)
OPCURChoice
·
NO
Open 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_LINE
Graphics DisplayWritten as 3_PHASE (3 phase view), SINGLE_LINE (Single line view)
ViewBChoice
·
HIGH_VOLTAGE
Graphics DisplayWritten as LOW_VOLTAGE (Low Voltage Display), HIGH_VOLTAGE (High Voltage Display)
Breaker Main Data
Parameter
Unit
Default
Description
NAMEReal
·
BRK
Breaker NameRange 0 to 1Used when Ctrl==0
NAMEAReal
·
BRKA
Breaker A NameRange 0 to 1Used when Ctrl==1
NAMEBReal
·
BRKB
Breaker B NameRange 0 to 1Used when Ctrl==1
NAMECReal
·
BRKC
Breaker C NameRange 0 to 1Used when Ctrl==1
ROFFReal
ohm
1.0e6
Breaker Open ResistanceAt least 1
RONReal
ohm
0.005
Breaker Closed ResistanceAt least 0
Pre-Insertion Data
Parameter
Unit
Default
Description
PRERReal
ohm
0.5
Pre-insertion ResistanceAt least 0.001
PostInsChoice
·
AT_NEXT_CURRENT_ZERO
Post-insertion removalWritten as AT_NEXT_CURRENT_ZERO (At next current zero), AFTER_SPECIFIED_TIME (After a specified time)
TDAReal
s
0.0
Time Delay for Closing Breaker(A)At least 0
TDBReal
s
0.0
Time Delay for Closing Breaker(B)At least 0
TDBOAReal
s
0.005
Minimum Time for Post-insertion RemovalAt least 0Used when PostIns