GB 50054-2011Code for design of low voltage electrical installations (English PDF)

Foreword

According to the requirements of Document Jian Biao [2002] No. 85 issued by the former Ministry

of Construction (MOC)-"Notice on Printing and Publishing the Development and Revision Plan of

National Engineering Construction Standards in 2001~2002", this code was Formulated through

revising "Code for Design of Low Voltage Electrical Installations" GB 50054-95 jointly by China

Electric Design & Research Institute Co., Ltd . and organizations concerned.

During the revision process, this code was reviewed and finalized by the drafting group on the

basis of wide investigation, earnest summary of practical experience and reference to relevant

international standards and foreign advanced standards as well as extensive solicitation for opinions.

This code comprises 7 Chapters and 1 Appendix. the main technical content includes general

provisions, terms, selection of electrical devices and conductors, layout of switchgear assembly,

protection against electronic shock in electrical installation, protection for power circuits and erection

of wiring systems.

The main technical rev isions are as follows .

1 The applicable voltage was changed from AC SOOY power frequency to AC lOOOV power

frequency;

2 The provision that copper and aluminium conductors shall be selected m the General

Provisions of the former code was cancelled;

3 The terms were added as a separate chapter while the term explanation in the Appendix was

deleted;

4 The requirements for the selection and installation of functional switching devices and

residual current action protection devices were added;

5 The requirements of selecting switching device with neutral pole were added;

6. The requirements of installing electrical devices for insulation monitoring in IT system were

added ;

7 The requirements for selecting sectional area of protective bonding conductor for local

equipotential bonding were added;

8 The "3 .2 Safety Precautions in Layout of Switchgear Assemhly" of "Chapter 3 Layout of

Switchgear Assembly" was incorporated into "4.4 Protection against Ea1th Fault" of "Chapter 4

Protection for Power Circuits" in the former code, and "SELV System, PELV System and FELV

System" were added in "Chapter 5 Protection against Electronic Shock in Electrical Installation";

9 The "Protection against Electrical Fire of Power Circuits" was added in "Protection for

Power Circuits" ;

10 The requirements for "wiring of pliable metal conduit", "wiring of underground concealed

metal trunking", "mineral insulated cable erection" and "pre-branch cable erection" were added;

11 Supplement, improvement and adjustment were made the partial provisions in the former

Contents

General Provisions ... 1

2 Tenns ... 2

3 Selection of Electrical Devices and Conductors ... 5

3 .1 Selection of Electrical Devices ... 5

3 .2 Selection of Conductors ... 7

4 Layout of Switchgear Assembly ... 13

5 Protection Against Electronic Shock in Electrical Installation ... 16

5 .1 Measure for Protection Against Direct Contact ... 16

5 .2 Measure for Protection Against Indirect Contact by Automatic Disconnection of Supply ... 18

6 Protection for Power Circuits ... 26

7 Erection of Wiring System ... 30

7 .2 Wiring of Insulated Conductors ... 31

7 .5 Wiring of Enclosed Busbar ... 3 7

7 7 Wiring of Electric Shaft ... 44

Appendix A Value of Factor k ... 46

Explanation of Wording of This Code ... 49

List of Quoted Standards ... 50

1 General Provisions

1.0.1 This code is Fonnulated with a view to ensuring personal and property safety, energy conservation,

advanced technology, full function, economic rationality, reliable electrical installation as well as

convenient installation and operation in the design of low-voltage electrical installations.

1.0.2 This code is applicable to the design of low-voltage electrical installations at 1 OOOV AC power

frequency in construction, extension and renovation engineering.

1.0.3 The design of low-voltage electrical installations shall not only meet the requirements of this

code, but also comply with those in the current relevant ones of the nation .

2 Terms