- LED luminaires for road and street lighting fall under BIS's Compulsory Registration Scheme, tested to IS 10322 (Part 5/Section 3).
- Registration numbers can be checked on the BIS CRS portal, crsbis.in.
- Lumen maintenance of LED chips is measured by IES LM-80 and projected by TM-21.
- A 30 W fitting at 120 lm/W gives about 3,600 lumens; at 90 lm/W, only about 2,700.
- IS 1944 Group B2 roads need about 4 lux average; Group A1 roads about 30 lux.
Wattage is the wrong starting point
‘How many watts?’ is the first question we get, every day. But watts tell you what the fitting eats, not what it gives. Two 30 W fittings can put very different amounts of light on the road, depending on how efficient the LEDs and driver are and how well the optic aims the light.
Start instead from the road: its IS 1944 class, width and pole height. Then choose the fitting that delivers that light with the fewest watts.
The six numbers that matter
| Parameter | What it means | What to look for |
|---|---|---|
| System efficacy (lm/W) | Light out of the whole fitting per watt drawn from the mains | Ask for the photometric test report; compare fitting lumens, not chip lumens |
| Light distribution (optic) | The shape of the beam on the ground | Road optics that throw light along the road, not a round spot |
| Colour temperature (CCT) | Warmth of the light, in kelvin | 2700K to 3000K for parks, promenades, heritage; 4000K for traffic roads |
| Colour rendering (CRI) | How natural colours look | 70 or above for roads; higher for plazas and markets |
| Power factor and THD | How cleanly the driver draws power | PF 0.9 or higher and low harmonic distortion, as your tender specifies |
| Surge protection | Survival of voltage spikes on long LT lines | A surge protection device rated as per tender; overhead-fed rural lines need it most |
Efficacy: compare fitting lumens, not chip lumens
LED chips can be very efficient on paper. But the driver loses some power, the lens absorbs some light, and heat reduces output. A datasheet that quotes ‘LED efficacy 180 lm/W’ may deliver 110 lm/W as a finished fitting. Always ask for the lumens and watts of the complete luminaire from a test report.
| Fitting | Watts | System efficacy | Lumens out | Monthly energy (10 h/night) |
|---|---|---|---|---|
| A | 30 W | 90 lm/W | 2,700 lm | 9 kWh |
| B | 30 W | 120 lm/W | 3,600 lm | 9 kWh |
| C | 24 W | 150 lm/W | 3,600 lm | 7.2 kWh |
Fitting C gives the same light as B for 20% less energy. Across 500 poles and ten years, that difference pays for a lot of maintenance.
Optics: the part everyone forgets
A decorative lantern with a bare LED module inside looks nice but throws most of its light sideways and into people's eyes. A road optic shapes the light into a long oval along the road, so you can space poles further apart and get more even light.
- For roads, ask for a road-type distribution suited to your width and mounting height.
- For heritage lanterns, ask whether the lantern has an internal road optic or only a diffuser.
- For parks and paths, a softer, wider spread with low glare works better than a narrow road beam.
- Ask for the IES or LDT photometric file so a lighting layout can be done in DIALux or similar software.
Colour temperature by application
| Application | Suggested CCT | Why |
|---|---|---|
| Heritage streets, temple approaches | 2700K to 3000K | Warm, matches old-city character, less glare |
| Parks, promenades, lakefronts | 3000K | Relaxed evening feel, kinder to insects and birds |
| Colony and society roads | 3000K to 4000K | Balance of comfort and visibility |
| Main and arterial roads | 4000K | Good visibility for drivers |
| Industrial areas, parking | 4000K to 5700K | Visibility over comfort |
Write the CCT in kelvin in your BOQ. ‘Warm white’ means different numbers to different suppliers.
Life and warranty
LED fittings rarely ‘die’; they slowly dim. The industry measures this with LM-80 tests on the LED chips and TM-21 projections, usually quoted as L70 (the hours until output drops to 70%). In real street lighting, the driver usually fails before the LEDs do, which is why tenders care about surge protection and driver quality.
Ask for a warranty that covers the driver, not only the LEDs. And make sure the driver is replaceable without changing the whole fitting.
Protection ratings
- IP65 minimum for all outdoor fittings; IP66 for coastal and water-edge sites. See our IP guide.
- IK07 to IK08 for fittings at 6 m and above; IK08 or higher for park lanterns within reach.
- Surge protection: essential on long overhead LT lines in villages, where lightning and switching spikes are common.
BIS registration: check it yourself
Road and street LED luminaires need BIS registration under the Compulsory Registration Scheme. The label should carry a registration number (usually starting with ‘R-’). Enter it on crsbis.in to confirm the manufacturer, brand and model series match what you are buying. It takes two minutes and filters out a lot of grey-market product.
Buyer's checklist
- Photometric test report with total fitting lumens and watts.
- IES/LDT file for layout design.
- BIS CRS registration number, checked on crsbis.in.
- IP and IK test reports for the exact model.
- CCT and CRI stated in the offer.
- Driver make, surge protection rating and replaceability.
- Warranty terms covering driver and LEDs.
References
- IS 10322 (Part 5/Section 3) — Luminaires for Road and Street Lighting — Bureau of Indian Standards
- BIS Compulsory Registration Scheme portal (verify registration numbers) — Bureau of Indian Standards
- IS 16107 (Part 2/Section 1) — Luminaires performance: LED luminaires — Bureau of Indian Standards
- IES LM-80 and TM-21 — Measuring and projecting LED lumen maintenance — Illuminating Engineering Society
- IEC 60529 — Degrees of Protection Provided by Enclosures (IP Code); Indian adoption IS/IEC 60529 — International Electrotechnical Commission / BIS
- IEC 62262 — Degrees of Protection Against External Mechanical Impacts (IK Code) — International Electrotechnical Commission
- IS 1944 (Parts 1 & 2): Code of Practice for Lighting of Public Thoroughfares — Bureau of Indian Standards
Frequently Asked Questions
Is BIS registration mandatory for LED street lights?
Yes. LED luminaires for road and street lighting are covered by BIS's Compulsory Registration Scheme and tested to IS 10322 (Part 5/Section 3). Check the registration number on crsbis.in.
What colour temperature is best for street lights?
2700K to 3000K for parks, promenades and heritage streets; 3000K to 4000K for colony roads; 4000K for main and arterial roads.
What efficacy should an LED street light have?
Compare the whole fitting's lumens per watt from a test report. Higher system efficacy means the same light for fewer watts; tenders usually state a minimum.
Why do LED street lights fail early?
Usually the driver fails, often due to voltage surges on long LT lines or heat. Surge protection, a quality driver and good heat sinking matter more than the LED chip brand.
30 वॉट की LED कितनी रोशनी देती है?
यह उसकी क्षमता पर निर्भर है। 120 lm/W वाली 30 वॉट फिटिंग लगभग 3,600 लुमेन देती है, जबकि 90 lm/W वाली सिर्फ 2,700 लुमेन।
BIS नोंदणी कशी तपासावी?
फिटिंगवरील 'R-' ने सुरू होणारा क्रमांक crsbis.in वर टाका. उत्पादक, ब्रँड आणि मॉडेल जुळतात का ते पाहा.
