Detail of GB/T 7251.4-2017

Introduction of GB/T 7251.4-2017

1 Scope Note: Throughout this part, the abbreviation ACS (ASSEMBLY for construction site, see 3.1.101) is used for a low-voltage switchgear and controlgear assembly intended for use on construction and similar sites. This part of GB/T 7251 defines the specific requirements of ACS as follows: ——ASSEMBLIES for which the rated voltage does not exceed 1,000 V in case of a.c. or 1,500 V in case of d.c.; ——ASSEMBLIES where the nominal primary voltage and the nominal secondary voltage of transformers incorporated in ACS are within the limits specified above; ——ASSEMBLIES intended for use on construction sites, both indoors and outdoors, i.e. temporary places of work to which the public do not generally have access and where building construction ,installation, repairs, alteration or demolition of property (buildings) or civil engineering (public works) or excavation or any other similar operations are carried out; ——transportable (semi-fixed) or mobile ASSEMBLIES with enclosure. The manufacture and/or assembly may be carried out other than by the original manufacturer. This part does not apply to individual devices and self-contained components such as motor starters, fuse switches, electronic equipment, etc. which will comply with the relevant product standards. This part does not apply to ASSEMBLIES for use in the administrative centres of construction sites (offices, cloakrooms, ASSEMBLY rooms, canteens, restaurants, dormitories, toilets, etc.). Requirements for electrical protection provided by equipment manufactured according to this part are given in GB/T 16895.7. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Chapter 2 of GB/T 7251.1-2013 is applicable except as follows Addition: GB/T 2423.19-2013 Environmental testing - Part 2: Test methods - Test Kc: Sulphur dioxide test for contacts and connections (IEC 60068-2-42: 2003, IDT) GB/T 7251.1-2013 Low-voltage Switchgear and Controlgear Assemblies - Part 1: General Rules (IEC 61439-1: 2011, IDT) GB/T 16895.7-2009 Low-voltage electrical installations - Part 7-704: Requirements for special installations or locations - Construction and demolition site installations (IEC 60364-7-704: 2005, IDT) GB/T 17045-2008 Protection against electric shock - Common aspects for installation and equipment (IEC 61140: 2001, IDT)

Contents of GB/T 7251.4-2017

Foreword i 1 Scope 2 Normative References 3 Terms and Definitions 4 Symbols and Abbreviations 5 Interface Characteristics 6 Information 7 Service Conditions 8 Constructional Requirements 9 Performance Requirements 10 Design Verification 11 Routine Verification 101 Particular Features of ACS Annexes Annex C (Informative) User Information Template Annex D (Informative) Design Verification Annex O (Informative) Guidance on Temperature Rise Verification Annex P (Normative) Verification of the Short-circuit Withstand Strength of Busbar Structures by Comparison with a Tested Reference Design by Calculation Annex AA (Informative) List of Notes Concerning Certain Countries Annex BB (Void) Annex CC (Informative) Items Subject to Agreement Between the Assembly Manufacturer and the User Bibliography Figure 101 Impact Test Using Striking Element Table 101 Values of Assumed Loading Table D.1 List of Design Verifications to be Performed Table AA.1 List of Notes Concerning Certain Countries Table CC.1 Items Subject to Agreement Between the Assembly Manufacturer and the User