Foreword

This code was revised from GB 50217-1994 Code for Design of Cables of Electric Engineering，by Southwest Electric Power Design Institute of China Power Engineering Consulting Group Corporation and the interests concerned in response to the Notice on Printing and Distributing the Preparation and Revision Plan of National Standards for Engineering Construction from 2001 to 2002（Jianbiao［2002］No.85）issued by the Ministry of Construction.

The technical contents involved in this revision mainly include:

1.Supplementing the requirements on selection of the number of cores of MV and HV cable；

2.Supplementing the requirements on selection of cable insulation，while deleting the contents related to adhesive impregnated paper insulated cables；

3.Supplementing the requirements on selection of the permissible minimum cross-section of protective ground wire in case of a main core cross-section of 400mm2＜S≤800mm2 and S＞800mm2；

4.Supplementing the requirements on the cross-section and material of cables in cases where power supply circuit of large current loads consists of multiple parallel-connected cables；

5.Supplementing the general requirements on selection of cable terminals；

6.Supplementing the contents on directly cutting and insulating the metallic layer of cables；

7.Supplementing the requirements on grounding of the metallic layer of three-core cables of AC systems；

8.Supplementing the requirements on the permissible distance between cables and conduits in urban cable systems；

9.Supplementing the requirements on arranging maintenance access of overhead cable trays；

10.Supplementing the requirements on placement interval of safety holes along cable tunnels；

11.Supplementing Appendix B and Appendix F.

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

This code is administered and explained by the Ministry of Construction of the People's Republic of China in respect of compulsory articles.The daily management of it is the responsibility of the Standardization Center of China Electricity Council.And Southwest Electric Power Design Institute of China Power Engineering Consulting Group Corporation is responsible for the interpretation of the specific technical issues therein.During the implementation of the code，the interests concerned are expected to seriously summarize the experiences and collect the relevant information based on the project practices and at any time refer any comments and suggestions to Southwest Electric Power Design Institute of China Power Engineering Consulting Group Corporation at the address:No.18 Dongfeng Road，Chengdu City，Sichuan Province，Postcode:610021，for reference in the future revision of the code.

This code is drafted by Southwest Electric Power Design Institute，China Power Engineering Consulting Group.The participants in the development of this regulation also include Northeast Electric Power Design Institute，and HILTI（China）Ltd.

The leading authors of this code:Li Guorong，Xiong Tao，Zhang Tianze，Qi Chun，Tao Qin，Wan Lining，Wang Xin and Wang Conghui.

This code is translated by SUNTHER Translation & Solutions under the authority of China Electric Power Planning & Engineering Association.