Solar Electrical Grounding & Bond Test Checklist [FREE PDF]

Proper electrical grounding and bonding is the most critical safety measure in photovoltaic systems, protecting personnel and equipment from fault currents, lightning surges, and electrical fire hazards as required by NEC Article 690 and IEC 62446-1. Electrical Inspectors must verify Equipment Grounding Conductor (EGC) continuity, grounding electrode system resistance, module bonding, and combiner box connections at commissioning and periodic intervals. This checklist aligns with ANSI/NETA MTS-2

  • Industry: Solar Energy
  • Frequency: Annually
  • Estimated Time: 60-90 minutes
  • Role: Electrical Inspector
  • Total Items: 41
  • Compliance: NEC Article 690 Solar Photovoltaic Systems (2023 Edition), NEC Article 250 Grounding and Bonding, IEC 62446-1 Grid Connected PV Systems – Minimum Test and Inspection Requirements, ANSI/NETA MTS-2021 Maintenance Testing Specifications for Electrical Power Equipment, NFPA 70E-2021 Standard for Electrical Safety in the Workplace

Pre-Test Safety & Energy Isolation

Confirm all safety prerequisites, energy isolation, and PPE requirements before commencing electrical grounding tests.

  • Has LOTO been applied to all inverters, combiners, and AC disconnects serving the test zone?
  • Has an absence of voltage been verified at test points using a CAT III or IV rated voltage tester?
  • Is the inspector wearing PPE appropriate for the incident energy level of the system being tested?
  • Has all test equipment been verified as calibrated and within its certification period?
  • Is weather suitable for testing (no precipitation, lightning risk within 30 miles, or standing water near test points)?

System Documentation & Design Review

Verify that as-built grounding drawings, conductor sizing records, and prior test reports are available and current.

  • Are as-built electrical single-line and grounding layout drawings available and stamped by a licensed engineer?
  • Are EGC conductor sizes documented and verified to comply with NEC Table 250.122 for the overcurrent protection rating?
  • Are results from the most recent prior grounding test available for comparison trending?
  • Is the grounding electrode conductor (GEC) size and installation method documented and code-compliant?
  • Note any discrepancies found between as-built documentation and physical field conditions.

Module Frame & Racking Bonding Test

Test and verify electrical continuity bonding of all PV module frames, racking components, and inter-row connections.

  • Are all PV module frames bonded to racking rails using listed bonding hardware (lugs, clips, or washers rated per UL 467)?
  • Is the measured bonding resistance between module frame and racking rail ≤0.1 Ω at all sampled test points?
  • Record the highest measured module-to-racking bond resistance value observed during sampling.
  • Are racking-to-racking splice connections bonded continuously with no isolated racking segments identified?
  • Are bonding jumpers at expansion joints or structural breaks installed per NEC 250.98 requirements?
  • Attach photo evidence of a representative module frame bonding connection tested during this inspection.

Equipment Grounding Conductor (EGC) Continuity

Test and verify EGC continuity from PV source circuits through combiners, inverters, and back to the grounding electrode system.

  • Is EGC continuity confirmed from each string combiner box to the inverter grounding busbar with resistance ≤1 Ω?
  • Is EGC continuity confirmed from inverter AC output panel to the main service grounding busbar?
  • Record the highest measured EGC resistance value observed in any string circuit tested.
  • Are all EGC conductors green, green with yellow stripe, or bare copper as required by code, with no substitutions?
  • Are EGC connections at all termination points torqued to manufacturer specification and free from corrosion?

Grounding Electrode System (GES) Testing

Test the grounding electrode system resistance using the fall-of-potential or stakeless clamp method.

  • Is the grounding electrode type (ground rod, grid, or concrete-encased electrode) correctly identified and documented?
  • Is the measured grounding electrode resistance ≤25 Ω (single rod) or within the project-specific design specification?
  • Record the measured ground electrode resistance value from fall-of-potential or stakeless clamp test.
  • Is the grounding electrode conductor (GEC) attached to the electrode using a listed clamp, exothermic weld, or listed connector?
  • Attach photo of the grounding electrode and GEC connection point.

Combiner Box & Inverter Grounding

Inspect and test grounding connections within string combiner boxes, inverter enclosures, and AC collection panels.

  • Is each combiner box enclosure bonded to the EGC with a listed lug and correct wire gauge?
  • Is the inverter chassis bonded to the EGC system with resistance ≤0.1 Ω to the grounding busbar?
  • Are all grounding busbars in combiner boxes and inverters free from corrosion, damage, and loose connections?
  • Is there a main bonding jumper (MBJ) correctly installed at the point of system grounding per NEC 250.24(B)?
  • Are surge protective device (SPD) ground leads connected directly to the grounding busbar with minimum lead length?

DC Insulation Resistance Testing

Perform insulation resistance (megger) testing on PV source and output circuits to identify insulation degradation or ground faults.

  • Was insulation resistance testing performed at 500V DC or 1000V DC as appropriate for the circuit voltage rating?
  • Is the measured insulation resistance of all DC source circuits ≥1 MΩ (minimum per IEC 62446)?
  • Record the lowest measured insulation resistance value observed across all strings tested.
  • Were any strings isolated for retesting due to IR values below 1 MΩ, and corrective action initiated?
  • Has the system ground fault detection/interruption (GFDI) device been tested and verified operational?

Test Results, Deficiencies & Closeout

Summarize all test results, classify deficiencies, assign corrective actions, and confirm restoration to service.

  • Have all measured test values been recorded in the test report with instrument make, model, and calibration date?
  • Have all deficiencies been classified by severity (Critical, Major, Minor) and assigned to responsible parties for correction?
  • Summarize all grounding and bonding deficiencies found, including location, severity, and recommended repair action.
  • Has LOTO been removed and system returned to service following successful completion of all tests?
  • Has the completed test report been signed, filed in the site O&M records, and a copy provided to the system owner?

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Why Use This Solar Electrical Grounding & Bond Test Checklist [FREE PDF]?

This solar electrical grounding & bond test checklist [free pdf] helps solar energy teams maintain compliance and operational excellence. Designed for electrical inspector professionals, this checklist covers 41 critical inspection points across 8 sections. Recommended frequency: annually.

Ensures compliance with NEC Article 690 Solar Photovoltaic Systems (2023 Edition), NEC Article 250 Grounding and Bonding, IEC 62446-1 Grid Connected PV Systems – Minimum Test and Inspection Requirements, ANSI/NETA MTS-2021 Maintenance Testing Specifications for Electrical Power Equipment, NFPA 70E-2021 Standard for Electrical Safety in the Workplace. Regulatory-aligned for audit readiness and inspection documentation.

Frequently Asked Questions

What does the Solar Electrical Grounding & Bond Test Checklist [FREE PDF] cover?

This checklist covers 41 inspection items across 8 sections: Pre-Test Safety & Energy Isolation, System Documentation & Design Review, Module Frame & Racking Bonding Test, Equipment Grounding Conductor (EGC) Continuity, Grounding Electrode System (GES) Testing, Combiner Box & Inverter Grounding, DC Insulation Resistance Testing, Test Results, Deficiencies & Closeout. It is designed for solar energy operations and compliance.

How often should this checklist be completed?

This checklist should be completed annually. Each completion takes approximately 60-90 minutes.

Who should use this Solar Electrical Grounding & Bond Test Checklist [FREE PDF]?

This checklist is designed for Electrical Inspector professionals in the solar energy industry. It can be used for self-assessments, team audits, and regulatory compliance documentation.

Can I download this checklist as a PDF?

Yes, this checklist is available as a free PDF download. You can also use it digitally in the POPProbe mobile app for real-time data capture, photo documentation, and automatic reporting.

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