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IEC 62504: Terms and Definitions for General Lighting LED Products and Related Equipment
IEC 62504 is the definitive terminology standard for LED products used in general lighting. Published first in 2014 and consolidated with Amendment 1 in 2018 (edition 1.1), this standard establishes a unified vocabulary covering LED packages, LED modules, LED lamps, LED controlgear, and systems composed of these components. As the LED lighting industry has grown explosively — from a niche market in 2010 to over 65% of global lighting sales by 2020 — the need for precise, unambiguous terminology has become critical for manufacturers, specifiers, regulators, and consumers. IEC 62504 resolves terminology conflicts between regional standards (e.g., ANSI/IESNA, Zhaga, Zhaga International), harmonizing terms to support global trade and regulatory compliance.
100+
Defined Terms
4
Product Level Hierarchy
5
Annex Categories
2018
Latest Consolidated Edition
📖 1. The Terminology Framework
1.1 Product Level Classification
IEC 62504 establishes a clear hierarchical classification of LED products for general lighting, which is essential for understanding how the various component standards (IEC 62717 for LED modules, IEC 62612 for self-ballasted LED lamps, IEC 61347-2-13 for LED controlgear) relate to each other:
- LED package: An assembly of one or more LED dies that has no intended means of connection to an external circuit and is not intended to be directly connected to a mains supply. Examples include SMD LEDs (2835, 3030, 5050 packages) and chip-on-board (COB) arrays.
- LED module: An assembly of one or more LED packages on a printed circuit board with electrical connections and possibly optical, thermal, and mechanical interfaces. A module may require an external controlgear to operate from mains.
- Self-ballasted LED lamp: A unit that cannot be disassembled without permanent damage, containing an LED light source and an integral controlgear with a standard cap for direct connection to the mains supply (e.g., an LED replacement for an incandescent bulb).
- LED controlgear: A device that provides the electrical interface between the mains supply and one or more LED modules or packages (equivalent to a ballast for fluorescent lamps).
💡 Engineering Insight — Terminology Boundaries Matter
The distinction between an “LED module” and a “self-ballasted LED lamp” has real regulatory consequences. In the EU, LED modules fall under the Ecodesign Directive via Commission Regulation (EU) 2019/2020, while self-ballasted LED lamps are covered by Regulation (EU) 244/2009 (updated by 2019/2020). Confusing one product type for the other can lead to non-compliant CE marking. Always verify which product category your design falls into before starting the compliance process.
The distinction between an “LED module” and a “self-ballasted LED lamp” has real regulatory consequences. In the EU, LED modules fall under the Ecodesign Directive via Commission Regulation (EU) 2019/2020, while self-ballasted LED lamps are covered by Regulation (EU) 244/2009 (updated by 2019/2020). Confusing one product type for the other can lead to non-compliant CE marking. Always verify which product category your design falls into before starting the compliance process.
1.2 Key Definitions in the Standard
| Term | Definition (Summary) | Relevant Standard |
|---|---|---|
| Rated luminous flux | Initial luminous flux declared by the manufacturer at rated conditions | IEC 62612 / IEC 62717 |
| Rated correlated color temperature (CCT) | Declared CCT in K, typically 2700 K, 3000 K, 4000 K, 5000 K, 6500 K | IEC 62612 |
| Color rendering index (CRI, Ra) | Measure of color fidelity compared to a reference source (max 100) | IEC 62612 |
| Lifetime (L70, L80, L90) | Operating time until luminous flux falls to 70%/80%/90% of initial value | IEC 62717 |
| Rated power | Input power declared by the manufacturer at rated voltage | IEC 62612 |
| Surge protection device (SPD) | Device limiting transient overvoltages | IEC 62305 / 61643 |
| Rated life (of controlgear) | Duration declared at specified operating conditions | IEC 61347-2-13 |
🔍 2. Detailed Architecture and Product Types
2.1 LED Package Types
The standard’s informative annexes (Annex A) provide a comprehensive overview of the LED product landscape. The key package types are distinguished by their construction and application:
- Mid-power SMD: Plastic-body packages (PLCC) rated 0.05–0.5 W per package. Used for indoor lighting, signage, and decorative applications. Typical efficacy: 130–180 lm/W.
- High-power SMD: Ceramic-body packages rated 0.5–5 W per package. Used for directional lighting, street lighting, and high-bay applications. Typical efficacy: 100–150 lm/W.
- Chip-on-Board (COB): Multiple dies directly mounted on a ceramic or aluminum substrate, rated 5–100 W per module. Used for spotlights, downlights, and architectural lighting. Typical efficacy: 120–170 lm/W.
- Filament LED: Multiple dies mounted on a glass or sapphire filament substrate, replicating the appearance of incandescent filaments. Used in decorative lamps and vintage-style bulbs.
2.2 LED Controlgear Categories
IEC 62504 distinguishes five categories of LED controlgear based on their output characteristics:
- Constant voltage (CV): Fixed output voltage (typically 12 V or 24 V d.c.) with current determined by the LED module
- Constant current (CC): Fixed output current with voltage determined by the LED load
- Dimmable: Capable of reducing output via phase-cut (TRIAC), 0–10 V, DALI, or PWM control
- Programmable: Adjustable output current via software or dip-switch settings
- Emergency: Controlgear with integral battery backup for emergency lighting
⚠️ Common Confusion — LED Module vs. LED Lamp
A frequent point of confusion in the industry is the distinction between an “integral LED module” and a “self-ballasted LED lamp”. The key difference is the cap/base. A self-ballasted LED lamp has a standard cap (E27, B22, GU10) that allows direct replacement of conventional lamps. An LED module does not have a standard cap and is intended to be wired into the luminaire by the manufacturer or installer. IEC 62504 clarifies that a self-ballasted LED lamp contains an LED module plus integral controlgear plus a standard cap.
A frequent point of confusion in the industry is the distinction between an “integral LED module” and a “self-ballasted LED lamp”. The key difference is the cap/base. A self-ballasted LED lamp has a standard cap (E27, B22, GU10) that allows direct replacement of conventional lamps. An LED module does not have a standard cap and is intended to be wired into the luminaire by the manufacturer or installer. IEC 62504 clarifies that a self-ballasted LED lamp contains an LED module plus integral controlgear plus a standard cap.
💡 3. Engineering Insights for Practical Application
Understanding IEC 62504 terminology is essential for navigating the broader LED standards ecosystem:
- Photometric parameter alignment: The terms “rated luminous flux,” “initial luminous flux,” and “maintained luminous flux” have distinct meanings. Rated luminous flux is the manufacturer’s declared value. Initial luminous flux is measured after 0–100 hours of burn-in. Maintained luminous flux is measured at specified intervals during life testing. These must not be used interchangeably in performance specifications.
- Color consistency terminology: The standard references the ANSI C78.377 binning system for CCT tolerance. Terms such as “nominal CCT,” “target CCT,” and “rated CCT” are precisely defined, and the allowed deviation (typically ±150 K for 2700 K, ±200 K for 4000 K) affects whether a product meets specification.
- End-of-life definitions: The standard differentiates between “catastrophic failure” (sudden, complete failure), “lumen depreciation failure” (end of useful life due to insufficient light output), and “chromaticity shift failure” (color change beyond acceptable limits). Different warranty terms apply to each failure mode.
✅ Recommendation — Cross-Reference with Product Standards
When writing performance specifications for LED products, always cross-reference IEC 62504 definitions with the relevant product standard. For example, when specifying a 4000 K LED downlight, use IEC 62504 to define “rated CCT” and “initial chromaticity coordinates,” then reference IEC 62717 for the photometric test method and IEC 61347-2-13 for the controlgear requirements. This creates a complete, unambiguous specification chain.
When writing performance specifications for LED products, always cross-reference IEC 62504 definitions with the relevant product standard. For example, when specifying a 4000 K LED downlight, use IEC 62504 to define “rated CCT” and “initial chromaticity coordinates,” then reference IEC 62717 for the photometric test method and IEC 61347-2-13 for the controlgear requirements. This creates a complete, unambiguous specification chain.
❓ Frequently Asked Questions
- Q1: Is IEC 62504 the same as the IEC 60050-845 (International Electrotechnical Vocabulary — Lighting)?
- No. IEC 60050-845 is the general lighting vocabulary covering all light sources (incandescent, fluorescent, HID, LED). IEC 62504 is a specialized supplement that provides LED-specific terms not found in the IEV. Together, they form the complete terminology set. Where a term is defined in both, the IEC 60050-845 definition takes precedence.
- Q2: Does the standard cover LED luminaires (complete light fixtures)?
- IEC 62504 covers LED packages, modules, lamps, and controlgear as components. Complete luminaires are covered by IEC 60598 series (general) and IEC 62722-2-1 (for LED luminaires specifically). The standard does define terms like “integrated LED luminaire” to clarify when the LED light source is non-replaceable.
- Q3: How does IEC 62504 relate to the Zhaga consortium standards?
- Zhaga standards (now part of the IEC under the IEC 62829 series) define physical interfaces for LED modules and controlgear. IEC 62504 provides the terminology that Zhaga standards reference. For example, Zhaga Book 18 specifies an outdoor LED module interface, and IEC 62504 defines what “LED module” means in that context.
- Q4: When specifying LED lifetime, what does L70B50 mean?
- L70B50 is a statistical lifetime metric. L70 means the time at which the light output has dropped to 70% of initial (or by 30%). B50 means that 50% of the population of products has reached this threshold. L70B10 would mean only 10% of products have reached 70% output. IEC 62504 defines these statistical terms precisely so that lifetime claims are meaningful and comparable across manufacturers.
