| DC System Rating | Rated operating voltage | 1,000 V DC or 1,500 V DC, according to the approved system design | Review nameplate, circuit diagram, component ratings, and test plan | Approved drawings, rating labels, and configuration records |
| Insulation Testing | Insulation resistance test voltage | Test voltage above 1,000 V DC; typical project levels include 1,500 V DC for 1,000 V-class assemblies or 2,500 V DC for 1,500 V-class assemblies | Use a calibrated insulation tester with the assembly isolated, discharged, and securely connected | Test voltage, duration, circuit configuration, operator, and instrument ID |
| Dielectric Strength | Withstand performance between live parts and enclosure or protective earth | No breakdown, flashover, or unacceptable leakage under the applicable standard and approved test plan | Apply the specified dielectric test after removing or protecting components that are not rated for the test | Pass/fail record, leakage-current record where applicable, and calibrated equipment certificate |
| Insulation Resistance | Resistance between conductors and accessible conductive parts | Must meet the minimum value defined by the applicable standard, product specification, and project acceptance criteria | Measure positive-to-earth, negative-to-earth, and positive-to-negative after correct isolation | Individual measurement results and environmental conditions during testing |
| Thermal Performance | Temperature rise at terminals, fuse holders, busbars, and cable entries | Temperature rise must remain within the limits of the applicable assembly standard and component datasheets; a 70 K terminal-rise reference is commonly used under relevant IEC 61439 conditions | Operate at the specified current until thermal stabilization; record ambient and component temperatures | Time-temperature curve, ambient temperature, load current, and thermal images |
| Current-Carrying Capacity | Continuous current of busbars, terminals, fuse holders, and cable connectors | Component current ratings must equal or exceed the design current after derating for ambient temperature and enclosure conditions | Compare design calculations with component datasheets and stabilized-load measurements | Load calculation, derating table, component certificates, and test report |
| Connection Integrity | Terminal torque and contact resistance | Torque values must follow the terminal or component manufacturer’s specification; resistance should be stable and free from abnormal heating | Use calibrated torque tools, visual inspection, and low-resistance measurement where required | Torque checklist, terminal photographs, and resistance results |
| Enclosure Protection | Ingress protection rating | IP54, IP65, or another specified rating according to installation location; classification should be verified under IEC 60529 | Inspect seals, cable glands, doors, drainage, and enclosure construction; conduct formal IP testing when required | IP test report, enclosure inspection record, and production photographs |
| Environmental Suitability | Operating temperature, humidity, UV exposure, and corrosion resistance | Typical outdoor project specifications use approximately −25 °C to +60 °C, but the final range must match the installation design | Review material selection, component datasheets, coating specifications, and environmental test results | Material certificates, coating records, environmental test reports, and warranty conditions |
| PV Fuse Protection | Fuse voltage, current rating, interrupting capacity, and polarity | Use photovoltaic-rated fuse links and holders selected for the system voltage, available fault current, and cable protection requirements | Verify fuse specifications, coordination calculations, and correct installation orientation | Fuse datasheets, coordination study, incoming inspection, and assembly checklist |
| Surge Protection | DC surge protective device rating and status indication | Selection should correspond to the maximum continuous operating voltage, earthing arrangement, and lightning-risk assessment; IEC 61643-31 is a relevant reference | Check UCPV, discharge-current rating, backup protection, wiring length, and visual status indicator | SPD datasheet, protection design, wiring inspection, and functional status record |
| Functional and Visual Inspection | Labeling, polarity, wiring layout, creepage, clearance, and component accessibility | Clear permanent markings and safe separation must comply with the approved design and applicable IEC requirements | 100% final inspection against drawings, wiring schedules, and workmanship criteria | Final inspection checklist, wiring photographs, serial traceability, and nonconformity closure |
| Calibration and Traceability | Test-equipment accuracy and product traceability | Measuring instruments should have valid calibration traceable to a recognized national or international standard | Audit calibration certificates, equipment IDs, batch numbers, and test-record linkage | Calibration certificates, test logs, production batch records, and corrective-action history |