I. Power Supply Safety Compliance Testing Requirements

Generally speaking, power supply safety compliance certifications in various countries are mostly stipulated from the following aspects:

1. ESD Distance:

ESD distance refers to the distance measured between two conductive bodies along the insulating surface, or the shortest distance between the conductive component and the equipment interface. This safety regulation is implemented to prevent power supply products from affecting personal safety due to arcing.

2. Electrical Withstand Voltage:

When a zero-voltage is applied between the AC input lines or between the AC input and the casing, and then increased to 1500V AC or 2200V DC, there should be no breakdown or arc discharge to be considered qualified.

3. Leakage Current:

Exposed and non-electrically charged metal parts should be connected to the ground. The measurement of leakage current is conducted by applying a 1.5kΩ resistor between these parts and the ground, and measuring the leakage current. For the leakage current of a switching power supply, under 260V AC input, it should not exceed 3.5mA.

4. Temperature:

The safety standards for electrical appliances place great emphasis on the temperature requirements, and also require materials to have flame retardancy. For switching power supplies, the internal temperature rise should not exceed 65°C, and if the ambient temperature is 25°C, the temperature of the power supply components should be less than 90°C.

Power supplies that do not meet safety standards do not have any direct adverse effects on users when they are first used, but over time, due to the influence of humid air and dust, it may cause short circuits in the high-voltage area, which not only causes damage to the power supply itself but also seriously affects the power grid, thereby adversely affecting other electrical appliances.

5. Electromagnetic Interference:

Electromagnetic interference is divided into conducted interference and radiated interference. Conducted interference is transmitted through power supply lines, with frequencies below 30 MHz, mainly interfering with the audio frequency band. Since computer switching power supplies have a metal shell, which shields radiation interference, power supply interference is more often manifested as conducted interference.

The magnitude of conducted interference is an important criterion for measuring the quality of computer power supplies. It includes two aspects: one is to prevent electromagnetic interference from the power grid from affecting the normal operation of the host system through the power supply; the other is to prevent the electromagnetic interference generated by the host itself from entering the power grid and affecting other electrical appliances.

II. Power Supply International CB System Certification

Making the safety test results of electronic and electrical equipment products globally accepted is the foundation of the CB system. After the product passes the CB test, it can obtain a CB inspection certificate and a CB inspection report. These two documents together constitute a passport to the global market.

1. Importance of Power Supply CB Certification:

Manufacturers can use the CB inspection certificate and report obtained to apply for global certification from national-level certification institutions within the CB system. Usually, no additional tests are required. When a power supply product with a CB certificate needs to be converted to a certification in a certain country, it can significantly reduce the certification cost and cycle, and quickly enter a new market; if it wants to enter the markets of some countries that still have their own certifications, it can pass the CB certification to indicate that the product has obtained international-level certification or approval.

2. Main CB Standards for Power Supply Products:

Power supply for information-related products    IEC 60950-1
Power supply for audio and video products    IEC 60065
General battery chargers    IEC 60335-2-29, IEC 60335-1
General isolated power supply (output voltage greater than 50VAC, 120VDC less than 1000VAC, 1415VDC)    IEC 61558-2-4
General safety isolated power supply (output voltage less than 50VAC or 120VDC)    IEC 61558-2-6
Switching power supply    IEC 61558-2-17
Power supply for toys    IEC 61558-2-7
Power supply for measuring instruments    IEC 61010-1
Power supply for medical equipment    IEC60601-1
Uninterruptible Power Supply (UPS)    IEC62040-1-1

3. CB certification materials for power supply products:

1) Product user manual;
2) Safety design file (including key structural diagrams, which can reflect creepage distance, gap, insulation layer number and thickness);
3) Product technical conditions (or enterprise standards);
4) Product electrical schematic diagram;
5) Product wiring diagram;
6) List of key components or raw materials (please choose products with European certification marks);
7) Copies of product or component certification certificates;
8) Other necessary materials.

Note: No factory inspection is required. The certification cycle is usually 2-3 weeks.

III. UL certification requirements for power adapters in North America

UL is the abbreviation of Underwriter Laboratories Inc. It is not only the most authoritative in the United States, but also one of the largest private institutions engaged in safety testing and certification in the world. UL certification mainly focuses on the detection and certification of product safety performance, but does not include the EMC characteristics of the product.

1. Importance of UL certification for power adapters:

Although UL certification is non-mandatory, it is highly recognized by American consumers. It can be said that power adapters without UL certification are difficult to be sold in the US market. The difficulty of UL certification varies depending on different standards, and the main issues include structure, materials, temperature rise, electrical clearance, creepage distance, etc.

2. Main UL standards for power adapters:

Power adapters for information-related products    UL62368, UL60950-1
Power adapters for audio and video products    UL62368, UL 60065
Power adapters for toy products    UL 697
Safety low-voltage power adapters (including chargers)    UL 1310
Non-safety low-voltage power adapters (including chargers)    UL 1012
Vehicle inverter    UL 458
Uninterruptible Power Supply (UPS)    UL 1778

IV. Latest 3C certification requirements for power adapters

The power supply of electronic products cannot do without chargers and adapters. Power adapters are external power supplies that connect to devices with a single wire and output DC power to meet stable low-voltage power supply under ideal power conditions. Power adapters for audio and video equipment and information technology equipment belong to the CCC certification scope and must complete 3C certification to be sold in the Chinese market.

1. Importance of 3C certification for power adapters:

On December 3, 2001, the State Quality Supervision Administration and the National Certification and Accreditation Administration released the 2001 No. 33 announcement "The First Batch of Products to Be Implemented Mandatory Product Certification Catalog" (hereinafter referred to as the Catalog), which includes 19 categories and 132 types of products. Among them, the 8th category of the Catalog "Audio and Video Equipment" and the 9th category of the Catalog "Information Technology Equipment" both include "Power adapters for audio and video equipment" and "Computer built-in power and power adapter chargers".

According to the "Regulations on Mandatory Certification Management", for products listed in the Catalog, since May 1, 2003, products without a mandatory product certification certificate and without the Chinese mandatory certification mark shall not be manufactured, imported or sold.

2. Main 3C standards for power adapters:

Safety requirements for audio, video and similar electronic equipment    GB8898-2011
Safety of information technology equipment - Part 1: General requirements    GB4943.1-2011
Electromagnetic compatibility - Limits - Harmonic current emission limits (for equipment with each phase input current ≤ 16A)    GB17625.1-2012
Sound and television broadcast receivers and related equipment - Limit values and measurement methods for radio disturbance characteristics - GB/T 13837-2012

3. 3C certification process for power adapters:

1) Certification application;
2) Type test (sample testing);
3) Result evaluation and approval (review and issuance of certificates);
4) First factory inspection within 3 months after certification;
5) Annual inspection once a year.

4. 3C certification materials for power adapters:

1) For each application unit, one main model sample and one sample covering the model should be sent;
2) If the sample is of a non-detachable structure, a detachable sample should be provided;
3) CCC application form (please fill in in Chinese and English);
4) Copy of the applicant's business license;
5) Product manual;
6) Product specification sheet;
7) Product maintenance manual (if any);
8) Product circuit diagram (including schematic diagram and printed circuit board layout);
9) Explanation of differences between the main model product and the covering model product in the same application unit (if any);
10) List of key components of the product related to safety and list of main components that have an impact on electromagnetic compatibility performance;
11) Chinese nameplate and warning signs;
12) Copy of the certification certificate of key safety components of the product;
13) Factory inspection questionnaire;
14) CB test certificate and report of the product (if any);
15) Trademark usage authorization letter (if any);
16) Declaration of conformity.