High-voltage circuit-breaker diagnostics: timing, contact resistance, coils and SF6
Enter your HV circuit-breaker measurements and get the status per test and subsystem, the likely cause and an action plan to IEC 62271 or IEEE C37.
Diagnose your high-voltage circuit-breaker Enter the nameplate data and field measurements (timing, travel, contact resistance, coils, SF6 and insulation) and get the status per test and per subsystem, the likely cause and an action plan to IEC 62271 or IEEE C37, with a report to print or download. Diagnose my circuit-breaker Close the diagnosis
What this tool does
It assesses a high-voltage circuit-breaker from the field measurements you enter and returns:
- The verdict: pass, pass with remarks, fail or critical, with the corresponding action and its priority.
- The status per test and per subsystem: mechanism and timing, control circuit and coils, wear and contacts, dielectric and interrupting medium.
- The likely cause and the action for each finding, based on manufacturers’ technical documentation and the circuit-breaker diagnostics literature.
- The health index per parameter and composite (CHI), where alert and failure limits are available, using the method of Dehghanian, Popovic and Kezunovic.
The report can be printed or downloaded in PDF, DOCX (Word) or ODT (LibreOffice), in the language of this page or, optionally, in twenty-one other languages. The curves and the history can also be exported to Excel (.xlsx) and LibreOffice Calc (.ods) with their charts.
Tests assessed
| Test | Compared against | Standards |
|---|---|---|
| Opening and closing times, simultaneity between poles | Manufacturer’s reference and tolerance or the circuit-breaker’s signature | IEC 62271-100 · IEEE C37.10 |
| Travel curve: speed, overtravel and rebound | Reference envelope | IEC 62271-100 |
| Main circuit resistance | Manufacturer’s value and difference between poles | IEC 62271-1 · ANSI C37.16 |
| Coils: current signature, minimum operating voltage | Control voltage range and reference signature | IEC 62271-1 · ANSI C37.16 · ANSI C37.32 |
| SF6 gas: density, leakage trend, moisture and purity | Filling, alarm and minimum functional levels | IEC 62271-1 · IEC 62271-203 |
| Insulation resistance, auxiliary contacts, motor and visual inspection | Manufacturer’s values and good practice | IEEE C37.10 |
How the status is determined
Each parameter is compared with its compliance limit (the manufacturer’s tolerance or the value in the standard) and with an earlier alert limit. Outside the tolerance the circuit-breaker fails; between the alert limit and the tolerance it passes with remarks. The status of each subsystem is that of its worst test, and the verdict is that of the worst subsystem. If you save successive tests of the same circuit-breaker, the History tab calculates the trend of each parameter and the estimated time until it reaches its limits.
Your data
The diagnosis is calculated in your browser and is not sent to any server. Data only leaves your browser if you ask for it: if you send the report by email (with a copy to Amperis) or if you save the test to your account history.
What this tool does not do
- It does not replace the manufacturer. The values, tolerances and curves in the circuit-breaker manual always take precedence.
- It does not measure. It assesses the measurements you take with your own test equipment; the quality of the diagnosis depends on the quality of the measurements.
- It does not decide on energisation. It supports the responsible engineer, who is the one who validates the result.
Further information and equipment
The measurements the tool asks for are taken with circuit-breaker analysers such as the CAT Advanced Series, with micro-ohmmeters such as the RMO-A for contact resistance, with coil analysers and, for SF6, with gas analysers and leak detectors. The full range is listed under Circuit-breaker testing. For gas mass and moisture, use the SF6 calculator and, to correct insulation readings for temperature, the insulation resistance calculator.
Indicative result. The calculation runs in your browser and is not sent to any server. This website may contain errors or omissions: before making any decision about an installation, the information must be checked and validated by a qualified engineer. The battery and circuit breaker diagnostic tools run on Amperis servers; calculations are not stored unless you expressly choose to do so. Legal notice and terms of use
Frequently asked questions
- What measurements do I need to use the tool?
- Whatever you have. The nameplate data (rated voltage and current, frequency and control voltage) and one test are enough, for example the opening and closing times or the contact resistance of each pole. Each test is assessed separately, and those that are missing are shown as pending, together with the standard that requires them. The more tests you enter, the more complete the subsystem diagnosis and the health index.
- Which criteria does it apply: IEC or IEEE?
- Those of the IEC 62271 series (62271-1, -100, -110 and -203) or those of ANSI / IEEE C37 (IEEE C37.04 and C37.10, ANSI C37.16 and C37.32), selected on the equipment sheet. Where the standard refers to the manufacturer, as for timing or contact resistance, the tool uses the reference and tolerance you enter or, failing that, the circuit-breaker’s own signature from a previous test.
- Can I import the curves from my circuit-breaker analyser?
- Yes. The Record tab reads COMTRADE files (.cfg/.dat or .cff), CSV or TXT, and .xlsx, .xls and .ods spreadsheets containing the travel, coil current, main and auxiliary contact, control voltage and dynamic resistance curves. You assign the use of each channel and the tool extracts the times, speeds, overtravel, rebound and the coil signature.
- Is my test data stored?
- No, unless you ask for it. The diagnosis is calculated in your browser. You can save each test to a .json file on your computer or, if you open a free account with two-step verification, to the history on the Amperis server, where only you can see it, to track how the circuit-breaker evolves.