A hipot tester applies a controlled dielectric-withstand test to an insulation system. Choosing one begins with the product’s required test plan, measurement range and protective workstation—not simply its maximum voltage or compact size. The result describes the specified test under its recorded conditions; the complete product-safety assessment has a wider scope.
This guide is for laboratory and production personnel specifying or reviewing a qualified test system. High-voltage test setup and operation belong to trained personnel using the exact equipment manual, approved procedure and applicable product requirements. The examples here contain no operating voltages, dwell times or trip settings.
Separate the tests before selecting the instrument
On a narrow screen, scroll the table horizontally. Keyboard users can focus the table region and use the arrow keys.
| Test | Primary question | Evidence to retain |
|---|---|---|
| Dielectric withstand / hipot | Does the specified insulation withstand the prescribed electrical stress without the defined failure? | Applied waveform and sequence, measured response, limits and result. |
| Insulation resistance | What resistance is measured under the specified DC test conditions? | Measurement timing, voltage, resistance and environmental conditions. |
| Ground bond / continuity | Does the intended protective bonding path meet its prescribed requirement? | Connection points, method, current/voltage conditions and result. |
| Touch or leakage current | What current is measured in the specified operating and fault arrangements? | Applicable measuring network, product configuration and test conditions. |
Associated Research’s verification paper distinguishes these functions and the need to confirm that a tester can detect a failure. A multifunction instrument can combine several capabilities, but each required function still needs its own approved setup and verification.
Use the product’s actual standard, edition, national deviations and certification procedure to resolve the requirements. Tables of generic test settings are inadequate substitutes for that decision.
Turn the requirement into a controlled test record
- Product identity, revision, intended market and the requirement being evaluated.
- Applicable standard/edition and the exact clause or certification procedure that authorizes the test.
- Type evaluation, production screening, repair verification or another clearly identified purpose.
- Connection points, product configuration, allowed accessories and any required conditioning.
- Approved waveform, sequence, timing, limits, measurement capability and decision rule.
- Responsible technical authority, operator authorization and treatment of failures or interrupted tests.
UL Solutions’ IEC 62368-1 service overview illustrates a product-family-specific evaluation route for audio/video and information/communication equipment. The applicable route for another product may differ. Establish that scope with the responsible laboratory before ordering equipment or adopting settings.
A failed result calls for the documented disposition process. Repeatedly retesting until a pass appears can hide an intermittent defect or an inappropriate setup. Preserve the first failure and the investigation that follows it.
Specify the fixture and protection with the tester
Include the device under test, leads, switching fixtures, enclosure, access controls, interlocks, emergency stop and residual-charge management in the system design. The manufacturer’s safe-workstation discussion describes an enclosure interlock and other protective elements. Their correct integration and validation depend on the real workstation.
Disabling an output and establishing that the test object is safe to access are separate parts of a qualified procedure. Stored energy, discharge behavior and indication must be addressed explicitly. Do not infer safe access from a green light or an elapsed time without the approved verification.
- Measurement range and uncertainty suitable for the acceptance limits, including the selected function.
- Output capability for the real load and waveform, including charging behavior where relevant.
- Fixtures and switching paths rated and arranged for the test, with reliable connection detection where required.
- Controlled recipes, access permissions, traceable records and dependable failure indication.
- Validated abort, interlock and recovery behavior for the complete station.
Request a representative demonstration using the agreed system requirements. A compact case can save bench space while the necessary protected test area still determines the installation footprint.
Check that the system detects the intended conditions
Calibration and in-service functional verification serve related but different purposes. Calibration establishes measurement evidence within its stated scope; a functional check challenges the actual path and failure response. Keep both records, including the fixtures and references used.
For UL-certified production, consult the current UL Follow-Up Services resources and the product’s applicable procedure for equipment and record requirements. Set the frequency and method through that governing process; this guide does not prescribe a universal interval.
- Define approved reference devices or verification fixtures for the required test functions and expected outcomes.
- Verify the configured system using the controlled method, including the relevant sensing and fixture paths.
- Confirm the expected pass/fail and protective responses, then retain the result with system identity and date.
- If verification fails, stop using the affected process, investigate and assess product tested since the last valid check under the quality procedure.
- Restore service only after the cause, correction and successful verification are documented.
The verification fixture itself needs appropriate design, ratings and control. An improvised high-voltage load is not a suitable substitute for the approved reference.
Plan throughput around the approved sequence
The purchasing record should end with agreed test scope, station requirements, verification method, record format and demonstrated capacity. That makes acceptance a reproducible engineering decision rather than a comparison of advertised headline features.
Keep a working record
Download the hipot testers worksheet (editable text). Save a copy for each comparison or test. It includes the example assumptions, fields for source references and space for your results.