Photovoltaic Cable Connectors: A Comparative Assessment of the Present State of the Industry

Research output: NRELPresentation


The consequences of failure for balance of systems (BoS) components (such as PV cable connectors) include offline module string(s); low system voltage; arc, ground, insulation, and over-temperature faults; triggered fuse(s); system shutdown; and fire. The degradation modes for connectors are studied here through an industry survey and its subsequent examination, which are compared to field-degraded specimens. 117 specimens were obtained from a variety of locations and climates or accelerated tests. A failure analysis for connectors from PV installations was developed (and applied to 54 specimens) including nondestructive examinations (photography, a custom resistance-current scan, and X-ray computed tomography) and destructive examinations (featuring milling of the external plastic, extraction of the internal convolute spring, and potting and polishing in cross-section). Surface and through-thickness composition of the metal pins and springs was quantified using scanning electron microscopy with energy-dispersive X-ray spectroscopy. Fourier-transform infrared spectroscopy was used to verify the base polymer materials and compare the chemical structure of the connector body, bushing, end nut, and o-ring. Thermogravimetric analysis and differential scanning calorimetry were used to further verify the degradation of the same polymeric components. Updated from 2023 NIST/UL Workshop on Photovoltaic Materials Durability (website: and 2024 PVRW workshop (
Original languageAmerican English
Number of pages42
StatePublished - 2024

NREL Publication Number

  • NREL/PR-5K00-87599


  • cable connectors
  • degradation
  • DSC
  • durability
  • EDS
  • FTIR
  • International PV Quality Assurance Task Force (PVQAT)
  • reliability
  • SEM
  • TGA
  • XCT


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