Electromagnetic compatibility requirements based on CCC certification of lighting electrical products

1 Introduction

The products covered by the China Compulsory Certification (3C Certification) lighting appliance certification implementation rules include:

1. Lamps (embedded, fixed, portable) with a power supply voltage higher than 36 V and not exceeding 1000 V;

2. Ballasts with a power supply voltage not exceeding 1000 V and AC electronic ballasts for tubular fluorescent lamps.

The following two national standards for electromagnetic compatibility must be met:

1. GB 17743-1999 "Limits and methods of measurement of radio disturbance characteristics of electrical lighting and similar equipment", equivalent to international standard Cl SPR1 5: 1996

2. GB 17625.1-2003  Electromagnetic compatibility limit harmonic current emission limit (equipment each phase input current ≤ 16A) is equivalent to the international standard IEC61000-3-2:2001. The GB 17743-1999 standard includes three test items: insertion loss, interference voltage and radiated electromagnetic interference, while GB 17625.1-2003 includes one test item: harmonic current emission.

Since different types of lighting appliances have different electromagnetic disturbance characteristics and different use environments, the standards define different test items, measurement methods and limit requirements. Before determining the test items according to the standards, the working principle of the product must be analyzed first, and the applicable test items must be determined according to its principle, working frequency and structure. The following will introduce the requirements and test methods of each item in GB 1774 3-1999 and GB 17625.1-2003 standards.

2 Inspection requirements and test methods

2.1 Disturbance voltage

The disturbance voltage is the disturbance level of the sample under test (hereinafter referred to as EUT) that is transmitted back to the power supply system through the cable and affects the surrounding environment. It is measured in voltage units and is divided into power terminal disturbance voltage and load terminal/control terminal disturbance voltage according to the different ports. The power terminal disturbance voltage is measured at the power port, and the frequency range is 9kHz~30MHz. The load terminal/control terminal disturbance voltage is measured at the load line and control line ports, and the measurement frequency range is 15OkHz~30MHz.

The measurement equipment of disturbance voltage includes: measurement receiver, artificial power network, voltage probe, and the measurement can be carried out in a shielded room. The shielded room is a large hexahedron made of metal materials (metal plates, metal mesh), and its four walls, ceiling and floor are all made of metal materials.

A metal plate with a thickness of at least 0.5 mm and an area of ​​at least 2000 mm x 2000 mm is used as a reference ground plane in the shielded room. Both the reference ground plane and the artificial power supply network should be connected to the shielded room ground.

If the luminaire is metal and has a grounding terminal (i.e. Class I appliance), the luminaire grounding terminal should be connected to the V-type reference ground. If the luminaire has a grounding terminal, but the manufacturer states that the luminaire does not need to be grounded, measurements should be made in both grounded and ungrounded conditions. If the luminaire is ungrounded (no grounding terminal), it should be placed on an insulating table 4-0 cm high for testing.

Separate electronic converters with non-detachable cables or for which the manufacturer provides strict installation instructions, and separate ballasts for fluorescent lamps and other gas discharge lamps should be measured together with the maximum loaded bulb on a piece of insulating material with a thickness of 12mm ±2mm.

Self-ballasted lamps and semi-luminaires are to be installed in a conical metal cover (see Figure 2) for testing. During the test, the distance between the EUT and the artificial power network is 800 mm; the distance to any other grounded object should not be less than 800 mm.

The disturbance voltage limits specified in GB1774-3-1999 are shown in Tables 1 and 2:

Figure 3 is an example of the power terminal disturbance voltage measurement results. Since all the final measured values ​​(represented by × in the figure) are below the quasi-peak limit, the test results are qualified. 2.2 Insertion loss

The insertion loss item is only applicable to inductive ballasts and fluorescent lamps driven by inductive ballasts. The main source of interference for such lamps is fluorescent light sources, and inductive ballasts are required to have sufficient suppression of electromagnetic interference, that is, sufficient loss must be inserted in the RF path. Insertion loss measures the ability of such lamps or inductive ballasts to suppress RF interference transmitted back to the power grid through the power line when the lamps are running, so the greater the insertion loss, the better.

The insertion loss limit values ​​specified in GB17743-1999 are shown in Table 3. The insertion loss test values ​​of all measurement frequency points must be greater than the limit values ​​in the table to be considered qualified.

The measurement equipment for the insertion loss project includes: measurement receiver, RF signal generator, balanced/unbalanced transformer, artificial power network, and simulated lamp. The balanced/unbalanced transformer is used to convert the unbalanced input of the measurement receiver to a balanced input. The simulated lamp is a standard test accessory used to replace the real fluorescent lamp. It provides a standard RF path (including impedance and capacitance) for the insertion loss measurement of the lamp to simulate the typical RF characteristics of the real fluorescent lamp. The specifications of the simulated lamp should be equal to the specifications of the fluorescent lamp specified by the lamp. Figure 4 is a photo of the simulated lamp and the balanced/unbalanced transformer.

The insertion loss measurement principle diagram is shown in Figure 5 below: