180–260
360°
IEC 62793
33+
2024 edition — open area protection
Thunderstorm Warning System standard
Documented safety compliance records
Remote alerts & full event logging
Early warning before strike arrives
Lightning Warning System
What Is a Lightning Warning System?
A structural Lightning Protection System (LPS) intercepts a direct strike on a building. A Lightning Warning System (LWS) detects the approaching thunderstorm and triggers an evacuation before anyone is exposed. Both are required for complete lightning safety under IEC 62305:2024.
Malaysia records 180–260 thunderstorm days per year (MetMalaysia) — one of the highest in the world. Construction workers, outdoor plant operators, port workers, solar farm technicians, and anyone working in the open are at direct risk during this time. A single lightning fatality on a project site can result in work stoppages, regulatory investigations, legal liability, and reputational damage.
The TokaiLightning Warning System detects atmospheric electrical field changes up to 30–40 minutes before a strike is likely — giving workers time to evacuate safely and operations managers time to implement stop-work protocols.
LWS vs LPS — Know the Difference
LPS (Lightning Protection System)
Protects the structure from direct strikes. Air terminals, down conductors, earthing. Passive — activates on strike.
LWS (Lightning Warning System)
The 2024 edition formally introduces direct lightning strike risk to people in open areas into the risk management framework and recognises IEC 62793-compliant LWS as a valid preventive protection measure. This is a significant departure from previous editions which focused primarily on building protection.
Why It Matters
The Consequences of No Warning System
For hyperscale data centre construction, solar farm installations, and industrial developments — the risks of operating without an LWS are not theoretical.
A lightning strike on an outdoor worker is fatal or severely injurious. Malaysia's high Ng (ground flash density) values mean construction sites face statistically significant annual risk. One incident halts the entire project.
A lightning fatality on a Malaysian construction site triggers a mandatory DOSH (Department of Occupational Safety and Health) investigation, stop-work order, and potential prosecution under the Occupational Safety and Health Act 1994. An LWS provides documented evidence of a systematic preventive measure.
International hyperscale developers — Google, Microsoft, AWS, and their EPC contractors — increasingly require IEC 62305:2024 and ISO 45001 compliance on their Malaysia projects. Failure to implement an LWS may breach contractor safety plans and void site insurance cover.
Lightning-induced stop-work, equipment damage to tower cranes and external M&E, and construction delays compound into significant financial losses. Early warning enables planned, orderly shutdowns rather than emergency responses.
High-Risk Activities Without LWS
Under IEC 62305:2024, the following construction activities carry elevated lightning risk to personnel and must be covered by a stop-work protocol — which requires an LWS to trigger reliably:
Operation
How Tokai LWS Works
Four distinct alert states guide the site from normal operations through evacuation and safely back to work — with full event logging at every stage.
Detect
Electric field sensor monitors atmospheric charge build-up. 360° detection up to 30–40 min advance warning.
Warn
Advisory alert triggers. SMS sent to site management. Prepare-to-evacuate protocol activated.
Evacuate
Audible siren + high-intensity strobe activated site-wide. All outdoor personnel move to designated shelters.
All Clear
Storm has cleared. All-clear siren issued. Event logged to cloud. Operations resume safely.
Advance warning before typical strike
Wireless solar-powered — no mains needed
Continuous remote monitoring & reporting
ALRAS LWS
ALRAS System Components & Capabilities
- 360° atmospheric electric field detection
- Detects storm build-up 30–40 minutes in advance
- Single-point sensor covers typical construction site radius
- Configurable detection distance thresholds
- Compliant with IEC 62793 detection criteria
- High-decibel audible siren — clearly heard across large open sites
- High-intensity visual strobe beacon
- Multi-stage alert: Advisory → Warning → All Clear
- Wireless solar-powered siren stations (no mains connection required)
- Multiple siren nodes for large or complex site footprints
- Cloud-based monitoring dashboard (real-time)
- SMS alerts to designated site managers and safety officers
- Full event log: time, alert type, duration — exportable for OSHA records
- Remote system status monitoring
- API integration with site management systems (where applicable)
- Solar-powered with battery backup — fully autonomous
- Wireless communication between detector and siren nodes
- Minimal civil works required for installation
- Rapid deployment — suitable for temporary construction site use
- Weatherproof enclosure rated for tropical outdoor environments
- IEC 62305:2024 — recognised preventive protection measure for open areas
- IEC 62793 — Thunderstorm Warning System standard
- Supports ISO 45001 occupational health & safety management
- Supports OSHA Malaysia (Occupational Safety and Health Act 1994) compliance
- Alert event logs usable as documented safety evidence
- Site survey and detector placement optimisation
- System design tailored to site footprint and workforce size
- Full supply, installation, testing, and commissioning
- Operator and safety officer training
- Maintenance contracts and annual service available
Core System Components
Regulatory Compliance
Aligned with International Guidance
International Standard for Lightning Protection
The 2024 edition of IEC 62305 (Protection Against Lightning) is the foundational lightning safety standard. It now formally incorporates risk to people in open areas and recognises IEC 62793-compliant LWS as an important preventive protection measure — a significant new requirement for construction and industrial sites.
Thunderstorm Warning System Standard
IEC 62793 defines performance requirements, detection thresholds, warning output criteria, and installation requirements for Thunderstorm Warning Systems (TWS/LWS). It specifies how a system must behave across detection, advisory, warning, and all-clear phases to be considered compliant. The ALRAS system is designed to meet IEC 62793 operating concepts.
Occupational Health & Safety Compliance
ISO 45001 requires organisations to identify and systematically control occupational hazards, including lightning for outdoor workers. The OSHA Malaysia (Occupational Safety and Health Act 1994) places duty-of-care obligations on employers and contractors. An LWS with documented event logging provides auditable evidence of a systematic lightning risk control measure.
- Tokai — 33 Years of Lightning Safety in Malaysia
Tokai Engineering (M) Sdn Bhd has been Malaysia’s specialist in lightning protection, earthing, and surge protection since 1993. Our Lightning Warning System solution brings the same engineering rigour to personnel protection — delivering IEC 62793-aligned systems with full documentation for OSHA, ISO 45001, and international consultant requirements. We serve hyperscale data centre projects in Malaysia and across South East Asia.
Our Process
How Tokai Delivers Your LWS
From initial site consultation to handover and training — a single point of responsibility throughout.
- Temporary or Permanent Installation?
Tokai — with over 33 years of lightning protection practice in Malaysia — will conduct a full IEC 62305-2 risk assessment and issue a stamped report within an agreed programme. We serve clients all around Malaysia and across South East Asia.
Typical Application
Typical Applications
Why Choose Tokai Lightning Warning System?
Tokai brings practical site experience in lightning risk, earthing, surge protection, OSHE requirements and critical infrastructure delivery. We understand that warning systems must be simple enough for site teams to follow, robust enough for harsh environments and credible enough for management decision-making.
From deployment planning to alert response training, Tokai helps organisations build a lightning safety workflow that works in the real world, not just on paper.
Real-time lightning threat monitoring for exposed sites and operational facilities
Early warning alerts to support timely suspension of high-risk outdoor activities
Configurable alert zones, escalation levels and response procedures
Integration with siren, strobe, dashboard and notification workflows
Supports occupational safety, project governance and incident prevention
Useful for temporary construction deployments and permanent facility installations
Complements lightning protection, earthing and surge protection systems
Supports documented safety response and operational accountability
FAQ
Common Questions About Tokai Lightning Warning System
Understanding Lightning Warning Systems, IEC 62793, compliance requirements, and the ALRAS system from Tokai.
What is a Lightning Warning System (LWS)?
For certain building classes — including high-rise buildings, government structures, and facilities storing hazardous materials — LPS installation is required under JKR specifications and local authority requirements. For other buildings, an IEC 62305-2 risk assessment formally determines whether an LPS is warranted. Tokai can conduct this assessment and provide a stamped engineering report.
Is a Lightning Warning System required under IEC 62305:2024?
The IEC 62305:2024 edition formally addresses protection of people in open areas as part of lightning risk management, and recognises IEC 62793-compliant LWS as an important preventive measure. For hyperscale data centre construction in Malaysia, an LWS is increasingly required by international consultants, main contractors, and OSHA compliance frameworks — particularly where thousands of outdoor workers are exposed daily.
What is IEC 62793?
IEC 62793 is the international standard for Thunderstorm Warning Systems (TWS), also known as Lightning Warning Systems (LWS). It defines performance requirements, detection methodologies, warning thresholds, and installation criteria for systems designed to protect people in open areas from lightning risk. A system aligned with IEC 62793 is formally recognised by IEC 62305:2024 as a valid preventive protection measure.
What is the difference between an LWS and an LPS?
A Lightning Protection System (LPS) protects the building from direct strikes — air terminals, down conductors, and earthing intercept the strike and conduct it safely to ground. A Lightning Warning System (LWS) protects people in open areas — it detects the approaching storm and triggers an evacuation before anyone is struck. Both are required for complete lightning safety under IEC 62305:2024.
Does Tokai provide LWS in Malaysia?
Yes. Tokai Engineering provides ALRAS Lightning Warning System supply, installation, testing, commissioning, and maintenance across all of Malaysia — including Johor Bahru, Iskandar Puteri, Senai, Kulai, and the Sedenak Tech Park corridor. We are actively supporting hyperscale data centre construction and large-scale industrial projects throughout the digital infrastructure zones nationwide.
How does the ALRAS LWS support ISO 45001 and OSHA compliance?
ISO 45001 requires organisations to identify and control occupational hazards — including lightning for outdoor workers. The ALRAS LWS provides documented, timestamped event logs for every alert and all-clear, exportable as evidence of a systematic lightning risk control measure. This supports OSHA Malaysia (OSH Act 1994) duty-of-care obligations and helps contractors demonstrate compliance during audits and investigations. An LWS is increasingly required in site safety plans for hyperscale data centre and infrastructure projects in Malaysia.
Can the ALRAS LWS be installed on a temporary construction site?
Yes. The ALRAS system is specifically designed for rapid deployment on temporary construction sites — solar-powered, wireless, requiring minimal civil works. It can be mobilised quickly for a new site and relocated or extended as the construction programme progresses. Tokai advises on the optimal configuration for your site footprint and provides maintenance support throughout the project duration.
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The Tokai Lightning Warning System gives organisations the one resource they need most during a lightning threat: time. Time to stop work, protect people, secure operations and resume safely with confidence.