Solar System Commissioning SWMS

Solar system commissioning is the final electrical verification stage where a licensed electrical worker energises, tests and hands over a photovoltaic (PV) installation — including DC array isolation testing, polarity checks, insulation resistance, earth continuity, inverter parameter setting, anti-islanding verification and grid connection. The work involves simultaneous exposure to live DC voltages (often 600–1000 V DC at the array), AC supply at the switchboard, and elevated work on roofs or elevated work platforms. Under WHS Regulation 2025 sections 291 and 299, a Safe Work Method Statement is mandatory because commissioning combines High Risk Construction Work (electrical work where there is a risk of electric shock from energised parts, plus work at heights above two metres on most domestic and commercial roofs). The SWMS must be prepared before work commences, consulted on with workers, and kept available for inspection until the work is complete plus two years if a notifiable incident occurs.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Elimination — Where feasible, complete all string polarity, insulation resistance and continuity testing on the ground before modules are connected into series strings to eliminate live DC exposure at height.
2. 2Elimination — Cover array with opaque tarpaulins during pre-energisation inspection to reduce open-circuit voltage to near-zero, removing live DC hazard during physical handling of conductors.
3. 3Substitution — Use a CAT IV 1500 V rated insulation resistance tester and PV-specific multimeter (e.g. Seaward PV200 or equivalent) instead of standard electrician's multimeters not rated for DC fault currents.
4. 4Substitution — Specify and install load-break rated DC isolators compliant with AS 60947-3 in lieu of legacy non-load-break devices to permit safe under-load disconnection.
5. 5Engineering — Install permanent roof anchor points certified to AS/NZS 5532 prior to commissioning and connect twin-lanyard harness compliant with AS/NZS 1891.1 with shock absorber to nominated anchor.
6. 6Engineering — Use insulated tools rated to 1000 V per IEC 60900, finger-proof DC connectors (MC4 locking type) and lockout-tagout devices on AC main switch and DC isolators per AS/NZS 4836.
7. 7Administrative — Conduct documented pre-start briefing using this SWMS, verify electrical licence and CEC accreditation of all workers, and schedule commissioning outside peak irradiance and ambient temperatures above 35°C where practicable.
8. 8Administrative — Apply a permit-to-energise system requiring two-person verification of polarity, voltage and earth continuity readings against AS/NZS 5033 checklist before closing the DC isolator.
9. 9PPE — Wear arc-rated coveralls minimum ATPV 8 cal/cm², Class 0 insulated gloves with leather over-gloves tested within the last six months, arc-rated face shield and AS/NZS 1337 safety glasses during energisation.
10. 10PPE — Non-conductive Class E hard hat to AS/NZS 1801, AS/NZS 2210.3 safety footwear with electrical hazard rating, and high-visibility long sleeves to mitigate UV and incidental contact burns.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

On a 99 kW commercial rooftop PV commissioning job at a regional distribution warehouse, the lead electrician opens the day with a pre-start huddle on the loading dock and walks the two-person crew through this SWMS. Reviewing the hazard register, the apprentice flags that the southern array sits within 1.2 m of an unprotected skylight — not noted on the original install JSA. The team consults the controls section, escalates from administrative exclusion zoning to engineering control, and installs temporary skylight mesh covers before any roof access. Each worker signs the SWMS sign-on sheet, confirming current electrical licence numbers, harness inspection dates and Class 0 glove test certificates. During string testing the insulation resistance reading on String 7 returns 0.4 MΩ — below the AS/NZS 5033 threshold. Rather than energising, the supervisor pauses work, re-opens the SWMS, applies the lockout-tagout administrative control, tarps the affected string to drop Voc, and isolates a damaged MC4 connector chafed against a roof penetration. The fix is documented as a SWMS amendment in the site diary, the crew re-briefs on the change, signs the amendment column, and only then proceeds to grid energisation and AS/NZS 4777.2 anti-islanding verification with the inverter.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• AS/NZS 3000 — Electrical installations

Frequently asked questions