GB/Z 5169.50-2026Fire hazard testing for electric and electronic products - Part 50: Glowing/hot-wire based test methods - Fire containment test on finished units (English PDF)

Foreword

This document is a normative-type guidance technical document.

This document is drafted in accordance with the rules given in GB/T 1.1-2020, Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.

This document is Part 50 of Fire hazard testing for electric and electronic products. The parts of Fire hazard testing for electric and electronic products already published are listed in Annex NA.

This document is identical to IEC TS 60695-2-21:2023, Fire hazard testing - Part 2-21: Glowing/hot-wire based test methods - Fire containment test on finished units. The document type has been changed from an IEC Technical Specification to a Chinese national guidance technical document.

The following minimal editorial changes have been made to this document:

- to harmonize with existing standards, the title has been changed to Fire hazard testing for electric and electronic products - Part 50: Glowing/hot-wire based test methods - Fire containment test on finished units;

- ISO 13943:2017 and IEC 62368-1:2018, which are referenced informatively, have been moved from Clause 2 to the Bibliography; ISO 13943:2017 has been replaced by ISO 13943:2023 and IEC 62368-1:2018 by GB 4943.1-2022;

- the informative Annex NA has been added, listing the published parts of Fire hazard testing for electric and electronic products.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing authority shall not be held responsible for identifying any or all such patent rights.

This document was proposed by the China Electrical Equipment Industry Association and is under the jurisdiction of the National Technical Committee on Fire Hazard Testing of Electric and Electronic Products of Standardization Administration of China (SAC/TC 300).

Drafting organizations: China National Electric Apparatus Research Institute Co., Ltd., Hisense Refrigerator Co., Ltd., Guangdong Midea Refrigeration Equipment Co., Ltd., Qingdao Haier Refrigerator Co., Ltd., Vkan Certification & Testing Co., Ltd., Gree Electric Appliances, Inc. of Zhuhai, Nanchang Kechen Electric Power Test and Research Co., Ltd., Fujian Inspection and Research Institute for Product Quality, Wuhan University, Tsinghua Shenzhen International Graduate School, Huangpu Customs Technology Center, Beijing Tairuite Testing Technology Service Co., Ltd., Shenzhen Customs Industrial Products Testing Technology Center, Zhongshan Yuehai Electrical Appliance Co., Ltd., Hangzhou Jinsong Younuo Electric Co., Ltd., Shenzhen Meixin Testing Technology Co., Ltd.

Main drafters: Liu Xiuzhen, Wang Jun, Zhu Jiangao, Gao Yipan, Zhang Hanping, Luan Zhenxian, Gui Yi, Li Tangbing, Lei Xiaoyang, Huang Daochun, He Shengtao, Zheng Shaofeng, You Shali, Fan Jianbo, Gao Lingsong, Zhao Xingfang, Yan Jingen, Zhang Pan, Peng Jing, Dai Xingxue.

Introduction

The design of all electric and electronic products needs to take into account the risk of fire and the potential fire hazards. The design of components, circuits and parts, and the selection of materials, aim to reduce the potential risk of fire to a tolerable level even in the event of foreseeable misuse, malfunction or failure. Fire hazard testing for electric and electronic products is intended to save lives and protect property by reducing the number of fires or their severity. It does so by:

- preventing, as far as possible, ignition caused by live parts and, if ignition occurs, confining the fire within the enclosure of the electric or electronic product;

- minimizing, as far as possible, the spread of flame outside the product enclosure and the harmful effects of fire effluents, including heat, smoke and toxic or corrosive gases.

Fire hazard testing for electric and electronic products is planned to consist of 43 parts in three sub-fields:

- guidance and terminology for fire hazard assessment, comprising 1 terminology document and 8 assessment guides, intended to provide guidance and reference procedures for fire hazard assessment in this field;

- fire test standards, comprising 6 glowing/hot-wire based test methods, 10 flame test methods, 2 test methods for resistance to abnormal heat and 3 arc ignition test methods, describing small-scale test methods, for use by manufacturers and test laboratories of electric and electronic equipment, in which a specified heat source simulates the heat sources that can start a fire;

- hazard assessment of fire effluents, comprising 2 documents on corrosivity, 2 on smoke obscuration, 5 on toxicity, 2 on heat release and 2 on surface flame spread, giving guidance and the current state of test methods for measuring the toxicity, corrosivity, smoke obscuration and heat release of fire effluents from electric and electronic products and their materials.

At present, most fire hazard assessment techniques evaluate the flame retardant properties of a single material or component. Such techniques support the preselection and verification of materials and components, but cannot assess the interactions that may arise between materials or components in a complex environment, such as a finished unit, once a fire occurs.

Under fault conditions, electrical connections and contacts in a finished unit can overheat. Such overheating can be caused by corrosion, poor crimp connections, incorrect assembly, worn contact surfaces or mechanical fatigue. Overheating of insulating materials can in turn lead to ignition and fire.

Because the actual conditions of potential faults in a finished unit are difficult to simulate, all possible fire hazards should be taken into account at the design stage and in the subsequent preselection of materials and components.

This test is intended to verify that a finished unit can contain, within its fire enclosure, an internal fire of combustible parts in a simulated scenario of an overheated electrical connection.

1 Scope

This document describes a fire containment test method for finished units.