Foreword

This code is jointly revised by China United Engineering Corporation with relevant design and research organizations according to the requirements of the Notice on Printing and Distributing the Preparation and Revision Plan of National Standards for Engineering Construction for 2001 to 2002（JB〔2002〕85）issued by the former Ministry of Construction.

During the process，the code revision panel，based on the research on the existing code，has completed the first draft as well as drafts for comments，examination and approval with extensive investigations and studies，carefully summarized pratical experience and reference to related international standards and advanced foreign standards.At last，the code is finalized after review.

This code is organized into 7 chapters，mainly including:General，Terms，Load Classification and Power Supply Requirement，Power Source and Power Supply System，Voltage Selection and Electric Energy Quality，Reactive Power Compensation，Low Voltage Distribution.

The main revisions made are as follows:

1.Adjustments are made to the applicable scope of the existing edition.

2.One of the conditions for setting up self-contained power source is added:"If the condition for providing distributed generation is available，the energy use efficiency is high and the economic rationality is good"；also，the provision of"In special cases of switching from emergency power source to normal power source，if it requires short-time parallel operation between the both，measures shall be taken to ensure safety."is added；the 660V low voltage distribution level is included in this code for the first time.

3.Supplements，improvements and necessary revisions are made to the main technical contents of all chapters retained.

Articles in bold in this code are compulsory and must be enforced strictly.

This code is administered by the Ministry of Housing and Urban-Rural Development of the People's Republic of China which will also be responsible for the interpretation of compulsory provisions.China Machinery Industry Federation is responsible for its daily management，and China United Engineering Corporation is responsible for the interpretation of specific technical contents herein.The interests concerned are expected to seriously summarize experience and collect information during the implementation of this code and refer any comments and relevant information to China United Engineering Corporation at the following address for reference in the future revision of this code:No.338，Shiqiao Road，Hangzhou，Zhejiang，310022（E-mail:lusx@chinacuc.com or chenjl@chinacuc.com）.

The organizer，chief development organization，participating development organization，chief drafting staff and chief reviewing staff of this code are as follows:

Organizer:

China Exploration & Design Association of Machinery Industry

Chief development organization:

China United Engineering Corporation

Participating development organization:

China Huanqiu Contracting & Engineering Corporation（HQCEC）

China Aviation Industry Planning Design Institute

Northwest Electric Power Design Institute of China Power Engineering Consulting

Group Corporation

China Construction Design International Co.，Ltd（CCDI）

Chief drafting staff:

lv Shixiang　Chen Wenliang　Chen Jiliang　Xiong Yan　Gao Fengrong

Chen Youfu　Qian Lihui　Ding Jie　Gong Puzhan　Xu Hui

Chief reviewing staff:

Tian Youlian　Du Kejian　Zhong Jinghua　Wang Suying　Chen Zhongli

Li Daoben　Zeng Tao　Zhang Wencai　Gao Xiaoping　Yang Tong

Li Ping