What is the price of a lightning arrester for a building?

It depends on the protection level, building size, number of rods and down conductors, copper or GI tape, type of earth pits and SPDs, and brand. Send us your drawing or BOQ on WhatsApp for today's rate.

Is ESE lightning arrester better than a conventional one?

ESE arresters are rated to the French standard NF C 17-102 and claim a larger protection radius, which IS/IEC 62305 does not recognise. Follow the standard named in your tender or drawing; if none is named, design to IS/IEC 62305.

Should the lightning arrester earth be connected to the electrical earth?

Yes, the earth systems are normally bonded together as the design shows, so all metal stays at the same potential during a strike. Have a licensed electrician or lightning protection contractor make these connections.

How often should lightning protection be checked?

Check the earth resistance at every test joint and inspect clamps and joints at least once a year, ideally before the monsoon, and after any nearby strike.

Lightning arrester for building: how many, which type and earthing for sites in Gangtok, Namchi and Rangpo

Lightning arrester for building: design it to IS/IEC 62305 with air rods or mesh, two or more down conductors, tested earth pits and an SPD at the main DB.

A lightning arrester for a building is not one rod on the roof. It is a full system: air terminals (rods or a roof mesh), at least two down conductors, earth pits with a test joint, and surge protection (SPD) at the main DB. In India this is designed to IS/IEC 62305, and the number of rods and down conductors comes from the building’s size and protection level, not from a fixed rule.

This guide is for builders, contractors and electricians working on hotels, schools, hospitals, offices and hydro or infrastructure sites in Gangtok, Namchi, Rangpo and Singtam. The same advice applies across North Bengal, Bihar and Sikkim. Lightning is a serious hazard in India: Down To Earth reported in December 2025 that lightning kills more people in India than any other natural disaster. Tall buildings on ridges and hilltops, common across Sikkim, stand out to a strike and need proper protection.

What parts make up a lightning protection system?

Shopkeepers and buyers often say “lightning arrester” for the whole system. When you write a BOQ, list each part separately so nothing is missed.

Part	What it does	What to write in the BOQ
Air terminal (rod / finial)	Catches the strike on the roof	Material (copper / GI / SS), length, base with fixing
Roof conductor or mesh	Joins all rods and covers flat roofs	Copper or GI tape / round conductor, size in sq mm
Down conductor	Carries the strike down the wall to earth	Number of runs, tape size, clamps / saddles
Test joint (test link)	Lets you disconnect and test each earth	One per down conductor, at a reachable height
Earth pit / electrode	Spreads the current into the ground	Pipe, plate or chemical electrode, pit cover
Bonding	Ties metal pipes, tanks, railings and the electrical earth together	Bonding clamps and conductor
SPD (surge protection device)	Stops the surge entering wiring and equipment	Type 1 or Type 1+2 at main DB, Type 2 at sub-DBs

Which standard applies: IS/IEC 62305 or NF C 17-102?

IS/IEC 62305 is the Indian standard for lightning protection. It has four parts: general principles (Part 1), risk management (Part 2), protection of the structure and people (Part 3), and protection of electrical and electronic systems inside the building (Part 4). Most government, PWD, hospital and institutional specs ask for IS/IEC 62305.

You will also see ESE (early streamer emission) arresters sold with a large “radius of protection”. These are rated to the French standard NF C 17-102. As this September 2026 industry explainer notes, IS/IEC 62305 does not recognise the extra radius claimed for ESE, and many consultants accept ESE only where the design also works on the normal rolling-sphere method. Our simple advice: follow the standard written in your tender or the consultant’s drawing. If none is written, design to IS/IEC 62305.

How many lightning arresters are needed for a building?

There is no “one rod per X square feet” rule. The designer first fixes the Lightning Protection Level (LPL I to IV) from a risk assessment (IS/IEC 62305-2), then places rods and mesh so the whole roof falls inside the protected zone. The commonly used design values from IEC 62305-3 are below.

Protection level	Rolling sphere radius	Roof mesh size	Typical down conductor spacing	Common use
LPL I	20 m	5 m × 5 m	10 m	Explosive / very high risk sites
LPL II	30 m	10 m × 10 m	10 m	Hospitals, hotels, data rooms
LPL III	45 m	15 m × 15 m	15 m	Schools, offices, apartments
LPL IV	60 m	20 m × 20 m	20 m	Low-risk buildings, sheds

Two practical points:

Every system needs at least two down conductors, spread around the building. A tall or long building needs more, at the spacing above around the perimeter.
Corners, parapets, water tanks, lift rooms, mobile towers and solar panels on the roof all need covering. These are the spots most often missed on site.

The LPL and final layout must come from a qualified designer or consultant. The table is a guide to help you read their drawing and estimate quantities.

What size of copper or GI tape for lightning protection?

IEC 62305-3 gives minimum sizes. For roof conductors and down conductors, the usual minimum is 50 sq mm for both copper and hot-dip galvanised (GI) steel. In practice contractors commonly use copper tape such as 25 × 3 mm (75 sq mm) or GI strip such as 25 × 3 mm or 25 × 4 mm. This is general trade practice, not a rule: always use the size in your drawing.

Item	Copper	GI (hot-dip galvanised)
Minimum cross-section (roof / down conductor)	50 sq mm	50 sq mm
Life in wet, misty hill air	Long	Good if galvanising is thick and joints are sealed
Cost	Higher	Lower
Where it suits	Hotels, hospitals, coastal or very damp sites	Sheds, schools, budget projects

In Sikkim’s damp, misty weather, use proper bolted clamps with bimetallic joints wherever copper meets GI or aluminium. Mixed metals corrode fast in wet air.

How many earth pits for a lightning arrester, and what resistance?

Each down conductor ends in its own earth electrode, through a test joint. So two down conductors means at least two lightning earth pits. These lightning earths should be bonded with the building’s other earths as the design shows, so that all metal sits at the same potential during a strike.

A common site target is an earth resistance of 10 ohm or less for the lightning earth system. This figure is widely used in specs, but check your tender. On rocky hill ground in Gangtok or Namchi, low resistance is hard to get with a plain pipe. Chemical earthing or a deeper, longer electrode usually helps. Our guide on chemical earthing vs pipe earthing explains the choice.

Do I need an SPD if I have a lightning arrester?

Yes. The arrester protects the building structure. It does not stop the surge travelling into your wiring, DB, inverter, CCTV, lift controller or computers. For that you need SPDs:

Type 1 or Type 1+2 SPD at the main incomer when the building has an external lightning protection system.
Type 2 SPD at sub-DBs and floor DBs.
Data-line SPDs for CCTV, internet and lift panels where needed.

An SPD needs a good earth and its own correctly rated backup MCB or fuse, as the maker states. If you are unsure how SPDs sit with MCBs and RCCBs in a DB, see MCB, RCCB, RCBO and MCCB explained.

What are the common lightning protection mistakes on site?

One rod on the roof with one thin wire down the wall. This is not a protection system.
Down conductors run inside the building or bunched together on one side.
Sharp bends and loops in the down conductor. Keep runs straight and bends gentle.
No test joint, so the earth can never be checked.
Rooftop solar panels, water tanks and dish antennas left outside the protected zone.
Joints left unsealed in damp hill weather, leading to rust and loose connections within a few seasons.
No SPD at the main DB.

Get the system installed and tested by a licensed electrician or a specialised lightning protection contractor, and get the earth resistance checked every year, ideally before the monsoon.

Why buy lightning protection material from a local dealer?

A lightning protection job needs many small items: rods, bases, tape, clamps, test links, electrodes, compound, pit covers, SPDs and MCBs. Buying everything from one place keeps the quantities right and the site moving. Shree Shyam Suppliers supplies earthing and lightning protection material along with switchgear and SPDs, gives itemised quotes on WhatsApp and delivers across Sikkim. See our earthing products for what we carry.

When you send us your list, Shree Shyam Suppliers can also check that the tape sizes, clamps, electrodes and SPD ratings match each other and your drawing, before the material goes up the hill.

Ordering tip

WhatsApp us your BOQ or drawing with: the standard (IS/IEC 62305 or ESE), number and length of air rods, tape material and size with total running metres, number of down conductors and test joints, type and number of earth electrodes (pipe, plate or chemical), SPD type and rating for each DB, preferred brand, and your site location (Gangtok, Namchi, Rangpo, Singtam or elsewhere). We’ll send an itemised quote with today’s rates.