How to Control the Quality of LED Lighting Products• LED Testing

As you are well aware, the quality of LED lamps is not solely determined by the manufacturing process; it also hinges on the reliability of our material suppliers.

we have always been committed to delivering LED products of the highest quality to meet the evolving needs of our customers. As an LED manufacturer that places paramount importance on product quality, we understand that the foundation of quality lies in the control of our material suppliers. We have consistently strived to ensure that every component used in our LED products adheres to the strictest quality standards.

We believe that a holistic approach to quality management is imperative.

Next, let me explain the main safety requirements in the international standard for LED luminaire control devices and the specific safety requirements that should be considered for LED luminaire control devices.

LEDs do not require preheating or trigger pulses to start working, and they can operate at very low safe voltages during normal operation. These are unique advantages of LEDs compared to other gas-discharge light sources. To fully utilize these advantages of LEDs, designing high-performance LED control devices is essential to ensure that the benefits of LED illumination are fully realized.

When designing LED control devices, the first step is to determine the classification of the LED control device based on the requirements of Chapter 6 in the IEC 61347-2-13 standard.

Please be aware that safety standards for LED luminaires and control equipment can vary from one country or region to another. Consequently, we will provide you with the relevant national and international standards and guidelines to ensure compliance with specific safety requirements. We kindly ask you to thoroughly review the entire article for comprehensive information.

1.Classification of LED Luminaire Control Circuits and Corresponding Applicable Safety Standards

(1) Control devices that solely have constant voltage output functionality or constant current output functionality, or devices that have both functions, should be tested in accordance with the IEC 61347-2-13 safety standard.

(2) Control devices that only have functionality for controlling LED brightness, flashing, or color changes should be tested according to the GB 19510.12/IEC 61347-2-11 safety standard.

(3)If a control device combines the functionality of both of the above (inseparable as one unit), it should be tested according to the IEC 61347-2-13 standard. (This is because the content of IEC 61347-2-13 is equal to or greater than that of IEC 61347-2-11.)

I EC 61347-2-13, “Control gear for lamps – Part 2-13: Particular requirements for d.c. or a.c. supplied electronic control gear for LED modules,” is a safety specification released by the IEC in May 2006 for control gear used with LED modules. In this standard, electronic control gear for LED modules refers to a unit inserted between the power source and one or more LED modules, which provides rated voltage or current to the LED module. This unit may include one or more individual components and may have functions for dimming, power factor correction, and radio interference suppression.

The standard primarily covers general terms, labeling, prevention of accidental contact with live parts, terminals, grounding protection, moisture and insulation resistance, dielectric strength, fault conditions, transformer heating tests, abnormal conditions, construction, creepage distances and clearances, screws/current-carrying parts and connectors, heat resistance/fire resistance, and resistance to cracking and corrosion, among other aspects.

Below, we provide an overview of some key provisions within the standard:

A.General Provisions (Article 4)

* Stand-alone control devices must comply with the requirements of IEC/EN 60598-1.

* Built-in control devices without independent enclosures and control devices designed for use with luminaires must be tested in accordance with the requirements of IEC/EN 60598-1 when installed together with the luminaire.

* Stand-alone SELV (Safety Extra Low Voltage) control devices must comply with the requirements of Annex I.

* LED control devices are generally categorized into constant current and constant voltage types. Control devices that are not purely voltage or current sources can be tested as either voltage sources or current sources based on their electrical characteristics.

B.Labeling (Article 7)

(1) Information to be clearly and securely labeled on the control device includes:

# Source marking (trademark, manufacturer, or supplier name)

# Model or manufacturer’s type symbol

# Identification as a stand-alone control device if applicable

# Interchangeable and replaceable components such as fuses, with clear and unambiguous relationships depicted graphically on the luminaire’s control device if included; otherwise, this information can be specified in the manufacturer’s product catalog

# Rated power supply voltage (or multiple dielectric voltage values), voltage range, power frequency, and power current, with power current available in the manufacturer’s product documentation

# Grounding symbol for identifying grounding connection terminals (these symbols should not be placed on screws or other easily movable components)

# Line diagrams indicating the location and purpose of connection terminals

# If applicable, tC values, with specific indications or provisions in the manufacturer’s product catalog for parts involving these values

# For constant voltage types, the rated output voltage

# For constant current types, both the rated output current and maximum output voltage

# If applicable, it should be noted whether the control device is exclusively intended for operating LED modules.

(2) Information that can be labeled on the control device or explained in the manufacturer’s manual includes:

# That the control device does not rely on enclosure protection to prevent electric shock

# Wire diameters matching input and output terminals

# Types of lamps controlled by the control device, their rated power, and the quantity of lamps

# Whether the control device has windings connected to the mains

# If it is an equivalent safety SELV control device, please specify.

C.Prevention of Accidental Contact with Live Parts (Article 8)

(1) Definition of Live Parts

Measurement of touch current: AC peak not exceeding 0.7mA, considering high-frequency factors and multiplied by a factor; DC value not exceeding 2mA; measurement using the network specified in IEC 60990 Figure 4.

Measurement of touch voltage: Peak voltage not exceeding 34V; measurement using a circuit with a non-inductive resistance of 50 kΩ.

(2) Control devices with a capacitance exceeding 0.5 μF must measure discharge voltage.

(3) Equivalent SELV control devices: The accessible parts in contact with live parts must comply with the structural and safety distance requirements for double insulation or reinforced insulation as specified in IEC 60065.

(4) SELV or equivalent SELV control devices meeting the following conditions can use bare terminals:

Under normal load conditions, the rated output voltage (for constant voltage types) or maximum output voltage (for constant current types) does not exceed 25V r.m.s.

Under no-load conditions, the output voltage does not exceed 33V r.m.s., and the peak voltage does not exceed 33V.

(5) Control devices with a rated output voltage greater than 25V must use insulated terminals.

(6) If Y capacitors are connected between primary windings, they must be connected in series with 1 Y1 capacitor or 2 Y2 capacitors, with both Y2 capacitors having the same capacitance, as tested according to IEC 60384-14.

D.Moisture Resistance and Insulation (Article 11)

(1) Control devices need to undergo moisture resistance testing under the following conditions:

Placed in a constant temperature and humidity chamber with a temperature of 20-30 degrees Celsius and a relative humidity of 91%-95% for a duration of 48 hours.

Subsequently, insulation resistance testing and withstand voltage testing should be conducted.

(2) Insulation Resistance Testing should be applied between different polarities of live parts, between live parts and external components, and between live parts and control terminals.

The basic insulation requirement is not less than 2MΩ, while double insulation/reinforced insulation requires not less than 4MΩ.

E.Fault Conditions (Article 14)

(1) Test voltage: Any voltage value between 0.9-1.1 times the rated voltage.

(2) During testing, the control device should be under the following conditions:

Operated with rated load, with the external temperature of the control device reaching the declared tc temperature value.

Wrapped in tissue paper in accordance with the specifications of ISO 4046-4 4.187.

(3) The following single fault tests should be primarily conducted, simulating one fault at a time:

Short circuit or open circuit conditions that do not meet the relevant IEC standards for capacitance, resistance, and inductance.

Short circuit tests for cases where creepage distance/electrical clearances do not meet requirements.

Short circuit tests for semiconductor components.

Short circuits composed of varnish, enamel, or fabric insulation.

Short circuit tests for electrolytic capacitors.

(4) After testing, insulation resistance tests and Annex A tests should be conducted to check for the generation of flammable gases and the occurrence of safety hazards resulting from material combustion or metal melting.

F.Construction (Article 17)

Unless treated with impregnation, materials such as wood, cotton fabric, silk, paper, and similar fibrous materials should not be used as insulation materials.

Printed circuits are permitted as internal connections.

The sockets/plugs of the output circuit should ensure that they are not hazardous when interchanged with plugs/sockets that comply with IEC 60083 and IEC 60906.

The standard IEC 61347-1:2015/AMD1:2017 was officially published on September 29, 2017, and was formally included in the IECEE (CB) certification system on October 11, 2017.

The main technical updates in the revised standard, compared to the original standard, include the following:

A.Revision of requirements related to integral overvoltage protectors in lamp control devices, covering terms, markings, humidity-dependent insulation resistance, and electrical strength.

B.The scope has been expanded from the original DC below 250V to below 1000V DC.

C.Clause 7 requires lamp control devices with integral SPDs connected to the ground to be marked with the protection earth symbol specified in IEC 60417-5019: 2006-08. If overvoltage protection devices are integrated into the control device, it should indicate “integral SPD” for Class I protection against electric shock.

D.Clause 8 includes requirements for non-integral wiring terminals, and it specifies that two resistors or Y2 capacitors should be connected in series for protection against electric shock.

E.Clause 11 introduces requirements for humidity-dependent insulation resistance and electrical strength. During insulation resistance and electrical strength tests, overvoltage protection devices (SPDs) compliant with IEC 61643-11 should be disconnected.

F.Clause 16 addresses fault condition testing, where only one SPD component can be short-circuited or disconnected at a time. Insulation of MCPCBs is recognized as basic insulation or supplementary insulation, and additional requirements for DC circuits are added.

G.Clause 16.3.2 contains significant modifications related to creepage distance and electrical clearance.

IEC 61347-2-13:2014 specifies special safety requirements for electronic control gear for LED modules used with DC or AC supplies up to 1,000 V (AC 50 Hz or 60 Hz), with output frequencies that may deviate from the supply frequency. These control gear are intended for use with LED modules for constant voltage or current operation at SELV or higher voltages. This standard supersedes and replaces the first edition published in 2006 and constitutes a technical revision. This version includes the following major technical changes compared to the previous version:

a) Replacing SELV equivalent requirements with SELV requirements and referencing SELV requirements in Annex L of IEC 61347-1:2007/AMD2:2012.

b) Referring to IEC 61347-1 for protection against accidental contact with live parts, moisture resistance and insulation, and electrical strength.

c) New Annex J for emergency lighting requirements.

In particular, when LED limiting elements are used as resistors within such luminaires, and these resistors are directly mounted on printed circuit boards, it is necessary to simulate LED short-circuit abnormal conditions and subsequently measure the temperature rise of the resistors. This temperature should be lower than the temperature limit of the printed circuit board.

The performance indicators of LED control devices directly affect the overall efficiency and service life of LED luminaires for lighting and other important operational functions. However, for all types of electrical equipment, safety standards are a higher-level requirement (mandatory requirement) to ensure that there are no hazards to users and the surrounding environment during normal use. Therefore, the performance indicators of LED control devices are meaningful only when they meet all safety requirements.

2.Testing of LED Luminaire Control Circuits

A luminaire is an apparatus that distributes, emits, or modifies light from one or more light sources. It includes all the components necessary for supporting, protecting, and identifying the light source, as well as the necessary circuit auxiliary devices and devices for connecting them to the power source, but it does not include the light source itself. Types of lighting luminaires and their control devices primarily include: luminaires, general luminaires, universal luminaires, adjustable luminaires, combination luminaires, fixed luminaires, portable luminaires, recessed luminaires, and more.

① Here are some definitions of these luminaire types:

② Commonly Tested Luminaires：

Chandeliers, Wall Lights, Ceiling Lights, Industrial Lights, Track Lights, Downlights, Spotlights, Street Lights, Garden Lights, Table Lamps, Floor Lamps, Floodlights, Flashlights, Children’s Lights, Nightlights, Aquarium Lights, Buried Lights, Stage Lights, String Lights, Neon Lights, Emergency Lights, Swimming Pool Lights, LED Bulbs, Lamp Tubes, AC Electronic Ballasts for Fluorescent Lamps, DC Electronic Ballasts for Emergency Lights, Ballasts for Fluorescent Lamps, Ballasts for Discharge Lamps, Electronic Ballasts for Discharge Lamps, Adapters for LED Modules.

③Common Luminaire Testing Standards

④ Specific items for lamp testing

⑤ Lighting fixtures, in addition to standard electrical safety testing, also need to address photobiological safety concerns, especially regarding blue light hazard. This hazard is associated with radiation in the 400nm to 500nm range and can cause photobiological reactions leading to potential retinal damage. Many markets and countries have specific regulations to control this hazard, especially for lighting products with prolonged exposure times exceeding 10 seconds, where photobiological mechanisms play a major role and are several times more significant than thermal damage mechanisms.

Practical experience is the sole means to verify the authenticity of our claims. Our company has conducted extensive research and testing to ensure that we can present the aforementioned content to you in a clear, understandable, and comprehensive manner.

Our vision is clear: to ensure that the same level of quality and precision you have come to expect from us is maintained throughout our global supply chain. To achieve this, we will comprehensively assess and enhance the quality management systems of our led raw material wholesale market, with a particular focus on their supplier quality assurance procedures. This commitment to quality will not only secure the reliability of our products but also reinforce our dedication to customer satisfaction.

We look forward to serving you even better in the international market. Please do not hesitate to reach out to us for any further information or discussions.