Cable Testing Chart

Use this worksheet after the calculator result to record cable ID, test type, test voltage, leakage or resistance, PI, fault-location data, continuity, instrument, and action note.

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Quick reference table

A cable testing chart is a calculator-led testing worksheet. It organizes insulation, hi-pot, fault-location, continuity, and capacitance results with the test method and qualified follow-up.

Cable testing worksheet

Cable testing worksheet
Item	Record from calculator	Follow-up
Cable ID	Circuit, length, voltage class, conductor data	Match drawings and terminations
Test method	IR, hi-pot, TDR, continuity, or capacitance	Confirm procedure and instrument rating
Test values	Voltage, leakage, resistance, distance, or continuity	Compare with baseline and method limits
Environment	Temperature, moisture, condition, terminations	Document field conditions
Action	Accept, retest, locate, repair, or investigate	Assign qualified-person signoff

Cable test method routing

Cable test method routing
Test method	Record on worksheet	Why it must stay separate
Insulation resistance	Test voltage, resistance, temperature, duration	IR trending is not the same as withstand testing
VLF or hi-pot	Voltage, duration, leakage, termination setup	Method limits and cable class control procedure
TDR or fault location	Velocity factor, reflection time, distance	Location data does not prove insulation condition
Sheath or continuity check	Shield, sheath, continuity path, terminations	Accessories can drive the action even when conductor tests pass

Formula basis

Insulation resistance = test voltage / leakage current. Fault distance = propagation velocity x reflection time / 2.

Test voltage is the applied DC, AC, VLF, or instrument voltage for the selected method.
Leakage current is the measured current during the test where applicable.
Propagation velocity and reflection time are used for fault-location screening.
Test method identifies which result type produced the worksheet entry.

Worked examples

Feeder cable test recordRecord cable ID, test method, voltage, leakage current, calculated insulation resistance, test duration, instrument, terminations, and the corrective-action note.

VLF cable retest packageDocument cable ID, voltage class, VLF voltage, duration, leakage trend, termination condition, discharge step, and retest plan before acceptance review.

Assumptions. Balanced load and line-to-line voltage assumptions behind this chart.

Cable tests require proper isolation, discharge, shielding, terminations, trained personnel, and method-specific procedures.
A calculator result does not replace manufacturer guidance, acceptance criteria, safety procedure, or field diagnosis.

Code and standard notes. Planning limits that should be checked before final equipment selection.

Use this chart as a maintenance log; verify NETA or IEEE cable testing practices, equipment manufacturer instructions, OSHA safety controls, adopted NEC installation context, AHJ expectations, and qualified-person review before acceptance or energization.

How to use this chart

1Identify the test methodStart with the calculator mode so insulation, hi-pot, fault-location, and continuity records do not get mixed.

2Attach field conditionsDocument test voltage, temperature, terminations, shielding, instrument, and discharge controls.

3Route the resultUse the worksheet to decide whether the next step is acceptance, retest, fault location, repair, or engineering review.

Worksheet checklist. Record source basis, review gaps, and assumptions before using the chart result.

Capture cable dataRecord cable ID, voltage class, length, conductor, insulation type, and termination status.
Capture test dataWrite method, instrument, voltage, duration, leakage, resistance, fault distance, or continuity result.
Capture actionList status, retest requirements, corrective action, and qualified-person signoff.

Common mistakes to avoid. Review these before turning chart current into an equipment decision.

Mixing test methods without recording which procedure produced the value.
Using a calculator result without documenting isolation, discharge, and manufacturer limits.
Treating a fault-location distance as a condition assessment without checking insulation, sheath, terminations, and repair evidence.

Frequently asked questions

These answers explain how to use the chart without turning a quick reference into a final design decision.

Can one cable test value approve a cable?

No. The value must be reviewed with method, voltage class, history, terminations, environment, and qualified testing procedure.

Why keep fault-location and insulation results together?

Cable condition decisions often need both electrical condition and physical-location context, especially when repair or retest planning is required.