| Applicable Standards | Support for IEC 62271-100, IEC 62271-1, IEEE C37.09, or the standard specified by the user. | Ensures test procedures, tolerances, and report formats match the intended acceptance or maintenance work. | Request the clause-by-clause test list, sample report, and operating procedure for the required standard. | 15% |
| Breaker Timing Measurement | Measurement resolution of 0.01 ms or better; stated timing accuracy around ±0.1 ms or better. | Accurate close, open, bounce, and pole-discrepancy measurements are essential for evaluating breaker operating performance. | Use a traceable time calibrator or certified pulse generator and compare results at several timing points. | 15% |
| Travel and Displacement | Linear travel measurement with approximately 0.1 mm resolution or better; suitable transducer mounting options. | Contact stroke, overtravel, rebound, and velocity data help identify mechanical adjustment and wear problems. | Check sensor range, mounting fixtures, calibration certificate, and compatibility with the breaker mechanism. | 12% |
| Contact Resistance Testing | DC test current selectable for the application, commonly including 100 A or higher; four-wire Kelvin measurement. | Low-resistance measurement detects loose connections, contact degradation, and abnormal pole-to-pole differences. | Verify current stability, measurement range, lead compensation, thermal protection, and repeatability data. | 12% |
| Insulation and Voltage Tests | Support for insulation-resistance, withstand-voltage, or related tests only when matched to the required voltage class and local procedure. | The test voltage, leakage-current measurement, interlocks, and discharge functions must be suitable for the VCB under test. | Confirm voltage/current ratings, test-circuit diagrams, safety interlocks, emergency stop, and discharge time. | 10% |
| Coil and Motor Current Analysis | Simultaneous recording of trip coil, close coil, motor, auxiliary contacts, and control voltage. | Current waveforms can reveal coil energization problems, latch friction, motor loading, and control-circuit faults. | Request channel count, sampling rate, input isolation, current-sensor ranges, and example diagnostic waveforms. | 10% |
| Sampling and Synchronization | Clearly stated sampling rate, synchronized analog and digital channels, and repeatable trigger control. | Synchronized channels prevent misleading timing relationships between contact movement, coil current, and auxiliary contacts. | Check the technical datasheet for sampling rate, trigger uncertainty, channel isolation, and storage capacity. | 8% |
| Breaker Compatibility | Adjustable control voltage and current ranges, flexible sensor fixtures, and support for single-pole or three-pole testing. | A technically accurate instrument can still produce invalid results if its connections or operating circuits do not match the breaker. | Provide the breaker wiring diagram and mechanical dimensions for a documented compatibility review. | 8% |
| Software and Reporting | Automatic calculations, waveform zoom, pass/fail limits, editable test templates, and PDF/CSV export. | Consistent reports improve traceability, maintenance decisions, audit readiness, and comparison between test dates. | Test the complete workflow using real sample data, including data search, report editing, export, and backup restoration. | 6% |
| Calibration and Traceability | Calibration certificate with instrument serial number, measured points, uncertainty, date, and traceability statement. | Traceability supports reliable acceptance decisions and helps identify measurement drift over the equipment life cycle. | Confirm the calibration interval, recommended recalibration service, uncertainty data, and available reference standards. | 8% |
| Safety and Field Usability | Interlocked test controls, emergency stop, discharge circuit, protected terminals, clear status indication, and rugged transport case. | VCB testing may involve stored mechanical energy and hazardous electrical energy; safe operation is a primary selection criterion. | Review the risk assessment, wiring diagram, protection functions, ingress rating, operating temperature, and field demonstration. | 6% |
| Technical Support and Service | Documented training, remote troubleshooting, spare sensors and cables, software updates, and defined response times. | Support quality affects measurement continuity, operator competence, and the total cost of ownership. | Request service-level terms, training agenda, spare-parts list, warranty coverage, and repair turnaround time. | 8% |