In brief
A lightning protection system consists of air terminals or a mesh, down conductors, earthing, and equipotential bonding and surge protective devices that protect the internal installation. Under Annex III of the Work Equipment Regulation, unless the standard specifies a period, this system is inspected once a year according to the TS EN 62305 series, with its design drawings checked, by an authorised person registered on EKİPNET. In areas where flammable substances are stored, lightning is an ignition source and is addressed separately both in building legislation and in the explosive atmosphere assessment.
What components make up a lightning protection system?
A single pointed rod on the roof is what most people picture when they hear “lightning rod”. Yet a lightning protection system is a chain, and the weakest link in the chain determines the success of the whole system: alongside the parts that capture the lightning current, conduct it down the outside of the building to earth and disperse it safely into the ground, internal protection is needed that also protects the installation inside the building from sudden overvoltages. The lightning protection periodic inspection report should also assess each link of this chain one by one.
| Component | Function | First thing checked in the inspection |
|---|---|---|
| Air termination (air terminal, lightning rod, roof mesh) | Capturing the lightning at a designated point | Physical soundness, bending, corrosion, whether new structures added to the roof remain within the protection zone |
| Natural components | Including suitable metal parts such as a metal roof or guardrails in the system | Continuity of connections |
| Down conductors | Conducting the current down the outside of the building to earth | Breaks, loose clamps, damage during later facade work |
| Test (measurement) joint | Allowing the earthing to be disconnected and measured | Accessibility, tightness, corrosion |
| Earth termination | Dispersing the current into the ground | Earthing resistance and connections |
| Equipotential bonding and surge protective devices | Preventing dangerous potential differences in metal services and electrical systems inside the building | Presence of connections, status indicators of protective devices |
A lightning protection system is designed according to the TS EN 62305 series of standards. The risk management part of the series determines whether a structure needs protection and which level of protection should be chosen; the other parts explain how external and internal protection are installed.
Which buildings require lightning protection?
The legislation requires lightning protection in several places:
- Under item 9 of Annex 1 of the Regulation on Health and Safety Measures in Workplace Buildings and Annexes, in places where flammable, explosive, dangerous and harmful substances are produced, processed and stored, and in buildings with high points such as tall buildings and chimneys, masts or pointed projections, the measures required by the legislation in force against lightning are taken and installations are set up.
- Art. 64 of the Regulation on the Protection of Buildings from Fire requires the provisions of the relevant regulations and standards to be fulfilled to protect buildings against the danger of lightning, and sufficient bonding and an earth termination network to be installed so that the lightning load can be conducted to earth without creating a risk to the structure or the installations inside it.
- Art. 111 of the same regulation requires a lightning protection installation complying with the relevant regulations and standards at LPG storage and filling facilities.
In OIZs (organised industrial zones) in Bursa and the surrounding provinces, facilities with tall chimneys, businesses using paint and solvents, facilities with fuel and LPG tanks, and large warehouses are typical examples of this scope. Whether an installation is required, and at what level, is determined by risk analysis at the design stage.
Lightning protection periodic inspection: what does the legislation say?
Annex III of the Regulation on Health and Safety Requirements for the Use of Work Equipment, in Table 3 as revised by the amendment of 23 December 2025, lists the lightning protection installation on a separate row and states its scope explicitly: mesh system, air termination rod, natural air termination components, lightning rod and similar.
The contract for the inspection service is drawn up via ISG-KATİP (the Ministry’s online OHS registration system) at least 1 day before the inspection and approved by both parties. The person carrying out the inspection states each defect found during examination and testing separately in the report. For the intervals for other installations and equipment, see our article on periodic inspection intervals for work equipment.
Points checked in the annual inspection
The inspection by the authorised person combines visual examination and measurements. You can also prepare before the inspection with the list below:
- Design and previous report: Have the installation design and records showing that the defects in last year’s report have been remedied ready.
- Roof access: Safe access to the roof for the person carrying out the inspection should be planned; if there is no guardrail or lifeline on the roof, work at height measures are decided in advance.
- Air terminals and mesh: Bending, breaks, corrosion and loose connections.
- Changes to the roof: Whether solar panels, antennas, outdoor air-conditioning units, ventilation stacks and advertising signs added later remain within the protection zone.
- Down conductors: Breaks along the facade, removed clamps, conductors cut during cladding or signage work.
- Test joints: Accessible, numbered and tight.
- Lightning protection measurement: Earthing resistance and electrical continuity of the conductors.
- Internal protection: Equipotential bonding and the status indicators of surge protective devices in panels.
Solar energy systems added to the roof later are the most common source of non-conformity we encounter: because the panel installation was not in the design, the air termination arrangement changes, but the installation is not reassessed. After such changes, have the design updated and the inspection carried out according to the new design.
Lightning protection earthing and reading the measurement result
Lightning protection earthing resistance should be low. The TS EN 62305 series recommends an earthing resistance of 10 ohms or less where possible when measured at low frequency; in addition, the configuration of the earthing system and its ability to disperse lightning current into the ground are assessed. When reading the report, pay attention to the following:
- Measurement points: Is a separate value given for each down conductor, or is there a single “compliant” statement?
- Connections: Has the report assessed the relationship between the lightning protection earthing and the building earthing, and the equipotential bonding?
- Defects: Is each defect written on a separate line, with its location and the recommended correction?
- Result: If there is a “non-compliant” result, has a re-inspection date been set after correction?
Remember that earthing resistance varies with soil moisture; a measurement taken in a dry period gives a more conservative result. For the logic of electrical installation earthing, see our article on earthing and residual current devices, and for reading reports in general, see how to read a periodic inspection report.
Lightning risk in storage areas
In areas with flammable liquid tanks, LPG tanks, solvent stores and silos where dust is generated, lightning is treated as an ignition source. Points to watch in these areas:
- Explosive atmosphere assessment: In the explosion protection document, lightning and static electricity are assessed among ignition sources. For the document, see our article on explosive atmospheres and the ATEX document.
- Tanks and pipelines: The earthing and equipotential bonding of metal tanks, filling points and pipelines are inspected together with the lightning protection installation.
- Open-air stacking: High stacking of flammable material in the open creates a new high point where lightning may strike.
- After a lightning strike: The Work Equipment Regulation requires equipment to be inspected by authorised persons after events that may impair safety, such as natural phenomena. If it is known that lightning has struck the installation, have it inspected without waiting for the annual inspection.
Stopping outdoor work such as roof work, scaffolding and cranes in stormy weather should also be written into the emergency plan; our article on cranes and work at height in strong winds provides guidance on work in wind and storm conditions. For storage rules for flammable liquids, see our article on storing flammable liquids.
At Bursa Sistemer OSGB, under our periodic inspection service we draw up your installation inventory, plan the annual inspections with authorised persons registered on EKİPNET and follow up the remedying of defects in the reports. You can track inspection dates with the OHS calendar.
Frequently Asked Questions
How often is a lightning protection inspection carried out?
Under Annex III of the Work Equipment Regulation, the lightning protection installation is inspected according to the TS EN 62305 series at least once a year unless a period is specified in the standards. An additional inspection is required in situations such as a lightning strike or changes to the roof.
Who can carry out a lightning protection inspection?
Electrical engineers, electrical-electronics engineers, technical teachers who graduated in electrical education, and electrical technicians and senior technicians registered on EKİPNET can carry it out. The person who maintains the installation may not carry out the inspection.
Can a lightning protection installation without design drawings be inspected?
Annex III requires the installation design to be requested during the inspection and requires the employer to have a design prepared for an installation that has none. The design should be prepared first, and the inspection carried out on the basis of conformity with the design.
How many ohms should the lightning protection earthing resistance be?
The TS EN 62305 series recommends an earthing resistance of 10 ohms or less where possible. In addition to the value, the configuration and connections of the earthing system are assessed; the final interpretation is made in the report by the authorised person carrying out the inspection.
What should be done after lightning strikes the installation?
First, check whether there is fire, smoke or an electrical fault, and implement the emergency plan if necessary. Then have the air terminals, down conductors, connections and surge protective devices inspected by an authorised person; do not wait for the annual inspection date. The incident and the inspection result are entered into the equipment records.
Equipment inventory and an inspection calendar under the new Annex III, with inspections carried out through our solution partners, plus report and defect follow-up.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.