Design, supply, installation, testing and commissioning of complete Lightning Protection System for the building/structure as per IEC 62305 / IS 3043 including air termination system, down conductors, earthing system, accessories, testing and documentation, complete in all respects.
2️⃣ APPLICABLE CODES & STANDARDS
The lightning protection system shall strictly comply with the latest editions of:
IEC 62305 (Part 1 to 4) – Lightning Protection
IS 3043 – Code of Practice for Earthing
IEC 62561 – Lightning Protection Components
NBC (National Building Code of India)
CPWD / PWD / MES Specifications
Manufacturer’s instructions and approved drawings
3️⃣ SYSTEM DESIGN REQUIREMENTS
Lightning protection shall be designed based on Risk Assessment as per IEC 62305-2
Protection Level: LPL III (unless specified otherwise in NIT)
Protection method:
✔ Air Termination Network
✔ Down Conductor System
✔ Earth Termination System
4️⃣ AIR TERMINATION SYSTEM
a) Vertical Air Terminals
Material: Aluminium / Copper / GI
Diameter: 16 mm (minimum)
Height: 600 mm to 1500 mm
Installed at roof corners, edges and as per rolling sphere method
Fixed with base and fasteners suitable for roof surface
b) Roof Conductor
Material: Aluminium strip 25×3 mm / 20×3 mm
Laid on roof in mesh / perimeter pattern
Supported on UV-resistant conductor holders
Jointing by approved clamps only (no welding)
5️⃣ DOWN CONDUCTOR SYSTEM
Material: Aluminium strip 25×3 mm / 20×3 mm
Minimum 2 down conductors per structure, evenly spaced
Down conductors shall be routed externally, protected against mechanical damage
Each down conductor shall be connected to independent earth electrode
Test joint shall be provided at 1.5 m height from ground level
6️⃣ EARTH TERMINATION SYSTEM
a) Earth Electrode
Any one of the following as specified in NIT:
Copper Bonded Earth Rod
Diameter: 17.2 mm
Length: 3.0 m
Copper thickness ≥ 250 microns
OR
GI Plate Earthing
Size: 600×600×6 mm
Depth: 3.0 m minimum
b) Ground Enhancement Material (GEM)
Low resistivity, environment-friendly, RoHS compliant
Minimum quantity: 25 kg per earth pit
c) Earth Resistance
Final earth resistance value:
≤ 10 Ohms (or as specified in NIT)
7️⃣ ACCESSORIES & FITTINGS
Test Link / Disconnecting Link (GI / Copper)
Conductor holders (UV resistant)
SS 304 clamps, saddles and fasteners
Inspection chamber with heavy-duty pit cover
Earthing identification board
Danger / lightning warning signage
8️⃣ INSTALLATION REQUIREMENTS
All materials shall be new, unused and approved make
Installation shall be neat, symmetrical and as per approved drawings
Sharp bends shall be avoided (minimum bend radius as per IEC)
All joints shall be electrically continuous and mechanically strong
No direct welding allowed on aluminium conductors
9️⃣ TESTING & COMMISSIONING
Earth resistance measurement using calibrated earth tester
Continuity testing of down conductors
Submission of test reports
As-built drawings after completion
🔟 DOCUMENTATION TO BE SUBMITTED
Manufacturer’s technical datasheets
Test certificates (CPRI / NABL where applicable)
Risk assessment calculation (if required)
Installation drawings
Earth resistance test report
1️⃣1️⃣ MODE OF MEASUREMENT
Air terminals: Number (Nos.)
Roof conductor / down conductor: Running Meter (RM)
Earth electrodes: Number (Nos.)
Complete system: Job / Set
1️⃣2️⃣ PAYMENT TERMS (TYPICAL GOVT NIT)
Rate shall include supply, installation, testing & commissioning
Nothing extra shall be paid
GST shall be paid as applicable
Work shall be completed as per approved schedule
1️⃣3️⃣ MAKES (AS PER NIT)
Lightning Protection System: Approved / Equivalent Make
Earthing Materials: CPRI / NABL Tested
Accessories: IEC 62561 compliant
✅ SHORT BOQ DESCRIPTION (FOR NIT ITEM)
Providing, supplying, installing, testing and commissioning of complete Lightning Protection System as per IEC 62305 & IS 3043 including air termination, down conductors, earthing system, accessories, testing and documentation complete in all respects as per direction of Engineer-in-Charge.