GB/T 24621.1-2021Application guide for electric safety of low-voltage switchgear and controlgear assemblies—Part 1: switchgear assemblies (English PDF)

Foreword

This document is in accordance with GB/T 1.1-2020 "Guidelines for Standardization Part 1: Structure and Rules of Standardization Documents" Drafting.

This document is the first part of GB/T 24621 "Guidelines for the Electrical Safety Application of Low-Voltage Switchgear and Control Equipment".

GB/T 24621 has released the following parts.

---Part 1: Complete switchgear.

This document replaces Part 1 of GB/T 24621.1-2009 "Electrical Safety Application Guidelines for Low-Voltage Switchgear and Control Equipment Sub. Complete Switchgear. Compared with GB/T 24621.1-2009, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

a) Other features have been modified (see 4.6, 4.2.5 of the 2009 edition);

b) Modified the mark of complete equipment (see 5.1, 4.3.2 of the 2009 edition);

c) Deleted the structural key points of the protection level of the internal compartment (see 5.2.4 of the 2009 edition);

d) The main points of the structure of the combination of switching devices and components have been added (see 6.5);

e) Modified the main points of the internal circuit and connection structure (see 6.6, 6.6 of the 2009 edition);

f) The main points of the structure of the external wire terminal have been added (see 6.7);

g) Modified the test voltage value and test voltage frequency in the power frequency withstand test (see 7.1.2, 6.4.3 of the 2009 edition);

h) Modified the contents of Table 6 and Table 7 (see Table 6 and Table 7; Table 5 and Table 6 in the 2009 edition);

i) Modified the verification method of short-circuit protection circuit and short-circuit withstand strength (see 7.3, 6.2 of the 2009 edition);

j) Modified the verification method of the short-circuit withstand strength of the protection circuit (see 7.4.4, 6.3.3 of the 2009 edition)

k) Modified the performance points of electromagnetic compatibility (EMC) (see 7.5, 6.7 of the 2009 edition);

l) Deleted Appendix B and Appendix D (see Appendix B and Appendix D of the 2009 edition).

Introduction

Low-voltage switchgear and control equipment are widely used in residential houses, public places, public welfare sites and other places.

The places where the gas equipment is equipped are equipped with this type of product.

As a result, the safety and reliability of low-voltage complete sets of equipment are very important, and the safety performance has also become a low Important factors that need to be considered when compressing a complete set of switchgear and control equipment. Fully understand the electrical safety technology of low-voltage complete sets of equipment, and be able to enter One step is to ensure the personal and equipment safety of the low-voltage complete set of equipment in use and operation. GB/T 24621 aims to describe low-voltage switchgear and The electrical safety technology of control equipment provides a guide for the safe application of low-voltage complete sets of equipment. It is planned to consist of two parts.

---Part 1: Complete switchgear. The purpose is to explain the important content related to the safety technology of the complete set of switchgear, and to open the complete set of Provide safety guidance on the operation and application of the equipment.

---Part 2: Control equipment equipped with electronic devices. The purpose is to explain the content related to the safety technology of electronic control equipment. The operation application of the equipment provides safety guidance.

This document serves as a guide for the safe application of all types of low-voltage switchgear sets, and provides guidance on the design, manufacturing, sales and use of low-voltage switchgear sets.

The safety structure and performance points that need special attention when used are elaborated, and the parts related to safety and reliability are made.

Re-explain that the temperature rise, short-circuit withstand strength, dielectric performance, effectiveness of the protection circuit, electrical clearance and creepage distance are explained one by one, as The safety application of low-voltage switchgear sets provides guidance to ensure the safety and reliability of low-voltage switchgear sets during normal operation.

1 Scope

This document provides safety application guidelines for low-voltage switchgear sets (hereinafter referred to as "complete sets of equipment") in the design, manufacture, sales and use.

Guide, gives the interface characteristics, information, structural points and performance points of low-voltage switchgear in safety technology that need to be considered. Related information.

This document is applicable to all types of low-voltage switchgear under the GB/T 7251 series of standards.

Note: When the products covered by this document work under the special conditions of use in GB/T 7251, corresponding additional clauses need to be added.

2 Normative references

The content of the following documents constitutes an indispensable clause of this document through normative references in the text. Among them, dated quotations Only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 2423.4 Environmental testing of electrical and electronic products Part 2: Test method Test Db. Alternating damp heat (12h 12h cycle ring)

GB/T 2423.17 Environmental testing of electrical and electronic products Part 2: Test method Test Ka. Salt spray

GB/T 4025 Basic and safety rules for human-machine interface signs and coding rules for indicators and operating devices

GB/T 4026-2019 Basic and safety rules for the identification of human-machine interface logos for equipment terminals, conductor terminals and conductor identification

GB/T 4205 Basic and safety rules for human-machine interface signs and operation rules

GB/T 4208 Shell protection grade (IP code)

GB/T 7251.1-2013 Low-voltage switchgear and control equipment Part 1: General

GB/T 11021 Heat resistance of electrical insulation and its representation method

GB/T 11026 (all parts) Heat resistance of electrical insulating materials

GB/T 16895 (all parts) low-voltage electrical installations

GB/T 17626.2 Electromagnetic compatibility test and measurement technology Electrostatic discharge immunity test

GB/T 17626.3 Electromagnetic compatibility test and measurement technology Radio frequency electromagnetic field radiation immunity test

GB/T 17626.4 Electromagnetic compatibility test and measurement technology Electrical fast transient pulse group immunity test

GB/T 17626.5 Electromagnetic compatibility test and measurement technology surge (impact) immunity test

GB/T 17626.6 Electromagnetic compatibility test and measurement technology Radio frequency field induced conducted disturbance immunity

GB/T 17626.8 Electromagnetic compatibility test and measurement technology Power frequency magnetic field immunity test

GB/T 17626.11 Electromagnetic compatibility test and measurement technology Voltage sag, short-term interruption and voltage change immunity test

GB/T 17626.13 Electromagnetic compatibility test and measurement technology AC power port harmonics, inter-harmonic waves and low-frequency immunity of power grid signals Disturbance test

GB/T 20138 The degree of protection of electrical equipment enclosures against external mechanical collisions (IK code)

GB/T 24276 A method for verifying the temperature rise of low-voltage switchgear and control equipment through calculations