{"id":334,"date":"2026-03-31T21:01:40","date_gmt":"2026-03-31T19:01:40","guid":{"rendered":"https:\/\/solarware.temarketinged.hu\/?p=334"},"modified":"2026-04-02T10:25:11","modified_gmt":"2026-04-02T08:25:11","slug":"inspection-and-testing-of-pv-systems","status":"publish","type":"post","link":"https:\/\/solarware.temarketinged.hu\/hu\/inspection-and-testing-of-pv-systems\/","title":{"rendered":"Inspection and Testing of Photovoltaic (PV) Systems"},"content":{"rendered":"

The inspection of residential-scale solar systems and industrial-scale solar parks must be performed in accordance with the MSZ EN 62446-1:2016<\/strong> standard and Decree 40\/2017 (XII. 04.) NGM<\/strong> (as amended in 2020). These inspections are mandatory prior to commissioning and at specified periodic intervals thereafter. With the global expansion of photovoltaic systems, industrial and residential Battery Energy Storage Systems (BESS)<\/strong> are also becoming common; these are classified as electrical installations and their deployment must comply with the National Fire Safety Regulations (OTSz)<\/strong>.<\/p>\n\n\n\n

A common misconception is that solar systems are maintenance-free. In reality, each component\u2014including PV panels, connectors, cabling, inverters, and energy storage units\u2014requires regular maintenance. Since PV systems operate on Direct Current (DC)<\/strong>, damaged insulation can lead to sustained arc faults<\/strong>, posing an immediate risk of fire and electric shock. Furthermore, many parts of a solar installation are located in hard-to-reach or concealed areas, making them difficult to assess through visual inspection alone. Consequently, instrumental testing is essential to ensure operational safety and efficiency.<\/p>\n\n\n\n

Instrumental Testing Following Visual Inspection:<\/h3>\n\n\n\n
    \n
  • Measurement of protective conductor continuity.<\/li>\n\n\n\n
  • Measurement of insulation resistance.<\/li>\n\n\n\n
  • Measurement of earth (ground) resistance.<\/li>\n\n\n\n
  • Polarity test.<\/li>\n\n\n\n
  • Measurement of open-circuit voltage ($V_{oc}$).<\/li>\n\n\n\n
  • Measurement of short-circuit current ($I_{sc}$).<\/li>\n\n\n\n
  • Operational testing.<\/li>\n\n\n\n
  • AC-side electrical safety measurements.<\/li>\n\n\n\n
  • I-V (Current-Voltage) curve analysis.<\/strong><\/li>\n\n\n\n
  • Continuity testing of connectors (as required).<\/li>\n\n\n\n
  • Verification of inverter efficiency.<\/li>\n<\/ul>\n\n\n\n

    The DC-side strings of a PV system remain energized as long as the panels are exposed to light. Therefore, system inspections must only be carried out by qualified professionals equipped with the appropriate Personal Protective Equipment (PPE).<\/p>\n\n\n\n

    Advanced Diagnostics: I-V Curve and Efficiency Analysis<\/h3>\n\n\n\n

    While I-V curve analysis<\/strong> and inverter efficiency testing are not part of basic electrical safety measurements, they are highly recommended for troubleshooting and monitoring system degradation. The primary advantage of I-V curve testing is that it measures the DC system under load in real-world conditions. The resulting characteristic curve can forecast numerous emerging issues:<\/p>\n\n\n\n

      \n
    • Shading effects.<\/li>\n\n\n\n
    • Panel soiling\/contamination.<\/li>\n\n\n\n
    • Physical damage to the panel surface.<\/li>\n\n\n\n
    • Early signs of degradation.<\/li>\n\n\n\n
    • Faulty connections.<\/li>\n\n\n\n
    • Damaged wiring.<\/li>\n\n\n\n
    • Bypass diode failure.<\/li>\n<\/ul>\n\n\n\n
      \"\"<\/figure>\n\n\n\n

      Figure 1: Impact of various faults on the I-V characteristic curve<\/em><\/p>\n\n\n\n

      Impact of Various Faults on the I-V Characteristic Curve:<\/h2>\n\n\n\n
        \n
      1. Steps in the curve:<\/strong> These appear when the integrated bypass diodes<\/strong> are activated. The width of the “step” depends on the size of the shaded area, while the number of steps corresponds to the number of affected panels. Shading can be caused by external objects, surface soiling, or physical damage.<\/li>\n\n\n\n
      2. Low short-circuit current ($I_{sc}$):<\/strong> This indicates module degradation, shading, or contamination. It may also suggest the presence of mismatched panel types within the string.<\/li>\n\n\n\n
      3. Low open-circuit voltage ($V_{oc}$):<\/strong> Usually indicates high panel temperature or degradation. Since $V_{oc}$ changes slowly relative to degradation, it may also point to other faults such as a shorted bypass diode or leakage current (PID \u2013 Potential Induced Degradation<\/strong>).<\/li>\n\n\n\n
      4. Rounded “knee” (inflection point):<\/strong> A less sharp curve indicates degradation, surface damage, corroded connectors, or internal cell soldering defects.<\/li>\n\n\n\n
      5. Low voltage ratio\/slope change:<\/strong> This phenomenon often results from faulty or oxidized connectors, poor MC4 connector crimping, loose connections, or undersized\/damaged cabling.<\/li>\n\n\n\n
      6. Steep drop in load current:<\/strong> Beyond shading and degradation, this can be caused by cell short-circuits, panel leakage current, or leakage current due to cable insulation failure.<\/li>\n<\/ol>\n\n\n\n

        Measurement Requirements<\/h2>\n\n\n\n

        To achieve accurate results during I-V curve tracing, a minimum irradiance of $1000 W\/m^2$<\/strong> (clear, sunny weather) is required. The measurements must be performed exclusively by qualified experts holding the necessary licenses and using certified diagnostic equipment.<\/p>\n\n\n\n

        Our company possesses the specialized instrument park, professional expertise, and regulatory authorizations required for the comprehensive audit and inspection of both residential and industrial-scale solar power plants.<\/p>","protected":false},"excerpt":{"rendered":"

        A common misconception is that solar systems are maintenance-free. In reality, each component requires regular maintenance.<\/p>","protected":false},"author":1,"featured_media":294,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-334","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-pv-systems"],"_links":{"self":[{"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/posts\/334","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/comments?post=334"}],"version-history":[{"count":6,"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/posts\/334\/revisions"}],"predecessor-version":[{"id":580,"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/posts\/334\/revisions\/580"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/media\/294"}],"wp:attachment":[{"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/media?parent=334"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/categories?post=334"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/solarware.temarketinged.hu\/hu\/wp-json\/wp\/v2\/tags?post=334"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}