master:breaker1 parametersPSCAD Single Phase Breaker

Every parameter of the PSCAD Single Phase Breaker (master:breaker1): 16 names, with the unit, the default and the meaning PSCAD gives each one. Copy a name into parameters().

What master:breaker1 is

Single Phase Breaker, a component of PSCAD's Master Library, filed under faults and switching.

Definition: master:breaker1
PSCAD name: Single Phase Breaker
Category: Faults and switching
Parameters: 16, in 5 groups; 7 carry a unit
Read from: PSCAD 5.0.0, 2026-11-07

Read and write master:breaker1 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:breaker1"):   # the exact definition, namespace first
    params = comp.parameters()           # every parameter, as PSCAD holds it
    print(str(params["CLVL"]))           # Current Chopping Limit, in kA

comp = project.find_all("master:breaker1")[0]
comp.parameters(CLVL="1 [kA]")           # 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, "CLVL") and px_set(...), which also records the old value so the case is put back at the end. Getting started shows them.

Animation State1
Configuration5
Internal Output Variables3
Pre-Insertion Data5
Breaker Main Data2

Animation State

Parameter	Unit	Default	Description
`BOpen`Choice	·	CLOSE	breaker statusWritten as CLOSE (close), OPEN (open)

Configuration

Parameter	Unit	Default	Description
`CLVL`Real	kA	0.0	Current Chopping LimitUsed when OPCUR==0
`ENAB`Choice	·	NO	Use Pre-Insertion Resistance?Select Yes to No to enable/disable pre-insertion resistanceWritten as NO (No), YES (Yes)
`NAME`Real	·	·	Breaker NameRange 0 to 1
`OPCUR`Choice	·	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)
`ViewB`Choice	·	HIGH_VOLTAGE	Graphics DisplayWritten as LOW_VOLTAGE (Low Voltage Display), HIGH_VOLTAGE (High Voltage Display)

Internal Output Variables

Parameter	Unit	Default	Description
`IBR`Text	·	·	Name for Breaker Current (kA)
`SBR`Text	·	·	Name for Breaker Status
`VBR`Text	·	·	Name for Voltage across Breaker (kV)

Pre-Insertion Data

Parameter	Unit	Default	Description
`PRER`Real	ohm	0.1	Pre-Insertion ResistanceAt least 0.001
`PostIns`Choice	·	AT_NEXT_CURRENT_ZERO	Post-insertion RemovalSelect how the post-insertion resistance be removedWritten as AT_NEXT_CURRENT_ZERO (at next current zero), AFTER_SPECIFIED_TIME (after a specified time)
`TD`Real	s	0.0	Time Delay for Closing BreakerAt least 0
`TDBO`Real	s	0.005	Minimum Time for Post-insertion RemovalAt least 0Used when PostIns
`TDR`Real	s	0.05	Time Delay for Bypassing Pre-Ins.At least 0

Breaker Main Data

Parameter	Unit	Default	Description
`ROFF`Real	ohm	1.E6	Breaker OPEN ResistanceAt least 0.001
`RON`Real	ohm	0.005	Breaker CLOSED ResistanceAt least 0

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