SANS 10313 and IEC 62305 can look intimidating from the outside — hundreds of pages covering risk, physical protection and surge measures. But an experienced inspector does not read them as a wall of clauses. They read them as a small number of questions, each of which has to be answered with evidence. Learn to think the same way and staying compliant becomes far less stressful.
What the two standards are actually for
In broad terms, IEC 62305 is the international series covering protection against lightning — it works from a risk assessment through to the physical lightning protection system and the surge protection measures that shield electrical and electronic systems. SANS 10313 is the South African standard for the protection of structures against lightning, and it is the reference an inspector will hold your site against locally. The detail differs, but the intent is shared: understand the risk, protect against it, and be able to show that the protection is in place and working.
Inspectors think in evidence, not activities
The single most useful shift is this: an inspector does not care that you did a test. They care that you can show the protection is currently adequate. “We test annually” is an activity. “Here is the current risk assessment, here are the earthing records, here is the continuity and surge status as of this week” is evidence. The standards are satisfied by the second, not the first.
The four things an inspection really examines
Almost everything an inspector looks at falls under four headings:
- The risk assessment. Does a current assessment exist for the structure, and does the protection you have actually match the risk level it identifies?
- The lightning protection system. Air terminations, down conductors and their fixings — present, continuous, and physically intact.
- Surge protection measures. Coordinated surge protection on the incoming and critical circuits, with devices that are healthy rather than spent.
- Earthing and bonding. An earth termination system within its design values, with equipotential bonding intact across the structure.
A year-round checklist
You do not need to memorise clause numbers to stay audit-ready. You need each of these to be current and on file at any moment an inspector, insurer or auditor asks:
- A risk assessment that reflects the structure and its use as it is today.
- Earth resistance records within the values your design calls for.
- Confirmed continuity of down conductors and earth mats.
- Surge protection device status — installed, coordinated, and not at end-of-life.
- Bonding and equipotential connections verified across services.
- Dated test and inspection records, with the responsible engineer identified.
- A remediation log showing that anything found out of spec was actually fixed.
Where annual testing leaves gaps
The checklist above has a weakness when it is fed only by once-a-year testing: every item is accurate on the test date and progressively less certain afterwards. Continuity can be lost, resistance can climb, and a surge device can expire the day after the tester leaves. Continuous monitoring keeps the evidence live — the earthing, continuity and surge status on your record reflect this week, not last summer — which is precisely the standard an inspector is trying to hold you to.
Make the audit a non-event
Compliance stops being a scramble when the evidence is always current and always in one place. That is the whole point of treating a certificate as the start of the job rather than the end of it: certify to the standard, keep the record live, and remediate the moment something drifts. Read the standards like an inspector, and you build a site that is not just compliant on paper, but demonstrably protected every day of the year.
Auditors do not reward good intentions. They reward evidence you can put on the table — current, complete, and signed.