I. Introduction to Certification

UL is the abbreviation of Underwriter Laboratories Inc. in the United States. UL Safety Testing Laboratory is the most authoritative in the United States and one of the largest private institutions engaged in safety testing and certification in the world. UL certification is a non-mandatory certification in the United States, mainly focusing on the testing and certification of product safety performance. The entire American market attaches great importance to product safety. More than 40,000 administrative regions across the United States, including federal, state, county and municipal governments, all recognize the UL certification mark. Amazon US also mandates that some products must have UL certification.

Ii. Certification Standards

Iii. Test Items

1. Input test

2. Temperature rise test

3. Impact/Drop test

4. Hot wire/needle flame test

5. Ball pressure test

6.LPS limited power test

7. Contact current test

8. Grounding impedance test

9. Constant temperature and humidity test

10. Vibration testing, etc

Iv. Required Documents

1.CDF(List of Key Components

2. Schematic diagram

3.PCB Layout

4. Label/Nameplate

5. Transformer specification sheet, inductor specification sheet

6. Model list/Difference Table

7. Product usage instructions or installation instructions, etc   

V. Certification Process

1. Quotation;

2. Arrange for the completion of the payment of relevant funds

3. Provide the application form, materials and test samples

4. Test and confirm the report

5. The review is passed and NOA/NOC is obtained

6.NOA can be shipped directly with the UL mark, while NOC can only be shipped with the UL mark after the first factory inspection is completed

Vi. Certification Cycle and Validity Period
The UL certification cycle is generally 3 to 4 weeks. Expedited service is available, but additional charges apply for expedited service.

Vii. Factory Inspection

UL audits factories four times a year, including quarterly audits and annual audits, as well as factory audits every year

The materials required for UL factory audit

1. Production and quality control Procedure book

2. Inspection standard books for major components and finished products

3. Records of major component certificates (yellow cards)

4. Material list of the product

5. Main documents for plastic material control

6. Main documents for production control

7. Records of UL labels

8. Recycling of Bulk labels for major component packaging

X. Certification Mark

For different types of UL services, the UL mark can be Classified into three categories: LISTED listing mark, Classified certification mark, and Recognize component certification mark. UL's services are not only based on the UL standards of the United States, but also on the Canadian standards (cUL). As a result, the UL mark is also divided into three types: for UL products, for cUL products, and for both. The "us" at the lower right corner of the UL mark indicates that it is applicable to the United States, and the "c" at the lower left corner indicates that it is applicable to Canada. If it has both "us" and "c", it is applicable in both countries.