IEC Short-Circuit Current Calculator
Declared IEC three phase initial symmetrical short circuit cUn/(√3|Zk|), independently established sequence impedance/voltage factor; not generic one phase U/Z, motor contributions or certified fault duty. Actual independently established compatible SI units/model context; conditional arithmetic, not code compliance, engineering design or safe operation approval.
Description
An initial three-phase symmetrical fault-current relation depends on an applicable voltage factor and positive-sequence impedance.
An initial three-phase symmetrical fault-current relation depends on an applicable voltage factor and positive-sequence impedance.1
This tool evaluates the supplied relation without determining equipment duty or all source contributions.
When to use IEC Short-Circuit Current Calculator
Use this tool to evaluate the supplied relation without determining equipment duty or all source contributions.
How to use IEC Short-Circuit Current Calculator and how it works
- Prepare callerApplicableVoltageFactor, lineVoltageVolts, actualPositiveSequenceImpedanceOhms, with the units, conventions and assumptions below.
- Enter the required fields and run IEC Short-Circuit Current Calculator.
- Read result.value using the output definitions below.
- Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| callerApplicableVoltageFactor | Caller Applicable Voltage Factor. Use the units and matching context stated in the calculation below. | number | Required; strictly positive; finite; other constraints below |
| lineVoltageVolts | Line Voltage Volts. Use the units and matching context stated in the calculation below. | number | Required; strictly positive; finite; other constraints below |
| actualPositiveSequenceImpedanceOhms | Actual Positive Sequence Impedance Ohms. Use the units and matching context stated in the calculation below. | number | Required; strictly positive; finite; other constraints below |
Supply positive voltage factor, line-to-line voltage in volts and equivalent impedance magnitude in ohms. Return factor*voltage/(sqrt(3)*impedance) in amperes for the simplified balanced three-phase calculation. The title does not imply a complete IEC study, source-network model or protection assessment.
currentAmperes=voltageFactor*lineVoltage/(sqrt(3)*impedance) Apply the input ordering, units and branch conditions stated above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Object containing the calculated or selected fields below. | object |
| result.value | Conditional signed or magnitude current in amperes under the tool's stated convention. | number |
{
"input": {
"callerApplicableVoltageFactor": 1,
"lineVoltageVolts": 10,
"actualPositiveSequenceImpedanceOhms": 1
},
"output": {
"result": {
"value": 5.773502691896258
}
}
}Limitations and assumptions
The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.
All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.
Alternative or Complementary methods
Use Peak Fault Current Calculator for a complementary operation: An asymmetrical fault-current peak uses an independently established peak factor in addition to symmetrical RMS current.
Use Arc Flash Incident Energy Calculator for a complementary operation: Arc-flash incident energy depends on a method edition, electrode geometry, fault current and protection timing.
References
-
IEC Short-Circuit Current Calculator — tool.io
Similar or alternative tools
- Peak Fault Current Calculator
An asymmetrical fault-current peak uses an independently established peak factor in addition to symmetrical RMS current.
- Arc Flash Incident Energy Calculator
Arc-flash incident energy depends on a method edition, electrode geometry, fault current and protection timing.