Leakage Current Screen Calculator

The Leakage Current Screen Calculator compares an entered Measured leakage current against an entered Reference leakage current. It produces the remaining Leakage margin, identifies whether the measured value is within that entered reference, and expresses leakage current as a percentage of the entered Load current.

This calculation supports maintenance records, troubleshooting documentation, commissioning worksheets, and comparison testing where a procedure, prior measurement, or equipment record supplies the reference value. It does not establish an acceptable leakage-current limit; the reference is entered by the user.

The calculator uses these fields:

Field	Electrical use
Measured leakage current	Leakage current measured during the applicable test, entered in mA
Reference leakage current	Comparison value from the applicable procedure or documented reference, entered in mA
Load current	Circuit or equipment load current used to express leakage as a percentage, entered in A

Leakage Margin and Reference Comparison

Leakage margin is the numerical difference between the entered reference leakage current and the measured leakage current:

\(\displaystyle \text{leakage margin} = \text{entered leakage reference} - \text{measured leakage current}\)

A positive margin means the measured leakage current is below the entered reference. A zero margin means the measured value equals the reference. A negative margin indicates that the measured leakage current exceeds the entered reference.

The calculator determines Reference comparison as follows:

\(\displaystyle \text{within reference when measured leakage current} \leq \text{entered reference leakage current}\)

The status is a comparison result, not a determination of equipment safety, shock risk, product compliance, or suitability for energization.

Leakage Percent of Load

The Leakage percent of load places the measured leakage current in relation to the entered load current:

\(\displaystyle \text{leakage percent of load} = \frac{\text{measured leakage current}} {\text{load current}} \times 100\)

Both values must be expressed in the same current unit before division. Because Measured leakage current is entered in mA and Load current is entered in A, convert milliamperes to amperes for the percentage calculation:

\(\displaystyle 2.4\text{ mA} = 0.0024\text{ A}\)

This percentage is context for the recorded operating load. It is not an ampacity calculation, branch-circuit loading calculation, feeder sizing result, voltage-drop result, or conductor-sizing determination.

Calculation Example

Enter the following values:

Input	Entered value
Measured leakage current	2.4 mA
Reference leakage current	3.5 mA
Load current	12 A

The leakage margin is:

\(\displaystyle 3.5\text{ mA} - 2.4\text{ mA} = 1.1\text{ mA}\)

The leakage percentage of load is:

\(\displaystyle \frac{0.0024\text{ A}}{12\text{ A}} \times 100 = 0.02\%\)

The resulting worksheet output is:

Result	Value
Leakage margin	1.1 mA
Leakage percent of load	0.02%
Reference comparison	Within entered reference
Load current used	12 A

Test Boundary and Field Verification

The worksheet performs arithmetic only: it compares the entered measurement to the entered reference and calculates the percentage relationship to load current. It does not provide a safety approval, product-compliance conclusion, shock-risk result, or energization decision.

Field decisions require the applicable test method, equipment documentation, maintenance procedure, measurement conditions, instrument suitability, and any requirements enforced by the AHJ or other governing authority. A measured leakage value can be meaningfully compared only when the reference and test conditions are appropriate to the equipment and procedure being documented.