GB/T 4942-2021Degrees of protection provided by the integral design of rotating electrical machines (IP code) - Classification (English PDF)

Foreword

This document was drafted in accordance with the rules given in GB/T 1.1-2020

Directives for standardization - Part 1.Rules for the structure and drafting of

standardizing documents.

This document replaces GB/T 4942.1-2006 Degrees of protection provided by the

integral design of rotating electrical machines (IP code) - Classification. Compared

with GB/T 4942.1-2006, except for structural adjustment and editorial changes, the

main technical changes are as follows.

a) The specified standards for the protection of machine enclosures from dust are

added in the "Scope" (see Chapter 1);

b) The definitions of closed machines and open machines are added (see 3.1 and

3.2);

c) The requirements for machines equipped with drain holes are modified in

Chapter 5 (see 5.4; see 4.4 of the 2006 edition);

d) The protection degree of IPX9 "machine protected against high temperature

and high-pressure water jet" is added (see 6.2);

e) The test and acceptance conditions for the dustproof test in the first

characteristic numeral test are modified (see Chapter 9; see Chapter 8 of the

2006 edition);

f) The test and acceptance conditions for the second characteristic numeral test of

IPX9 are added (see 10.1);

g) Figure 7 "Geometry of the fan jet nozzle" is added (see 10.1).

This document is identical to IEC 60034-5.2020 Rotating electrical machines - Part 5.

Degrees of protection provided by the integral design of rotating electrical machines

(IP code) - Classification.

The Chinese documents that have consistent correspondence with the international

documents cited in this document are as follows.

-- GB/T 1993-1993 Cooling methods for rotating electrical machines (eqv IEC

60034-6.1991);

-- GB/T 3836 (all parts) Explosive atmospheres [IEC 60079 (all parts)].

The following editorial changes were made to this document.

-- In order to be consistent with the technical standard system of China, the name

of the standard is changed to Degrees of protection provided by the integral

design of rotating electrical machines (IP code) - Classification;

-- The normative reference IEC 60079 (all parts) is added in Chapter 2;

-- For ease of understanding, the note in 10.2.3 a) is added;

-- "References" is added.

Please note that some contents of this document may refer to patents. The issuing

agency of this document assumes no responsibility for identifying patents.

This document was proposed by China Electrical Equipment Industry Association.

This document shall be under the jurisdiction of the National Technical Committee on

Rotating Machinery of Standardization Administration of China (SAC/TC26).

Drafting organizations of this document. Shanghai Electrical Apparatus Research

Institute (Group) Co., Ltd., Nanfang Pump Industry Co., Ltd., Jiamusi Electric Machine

Co., Ltd., Shanghai Engineering Research Center for Motor System Energy Saving Co.,

Ltd., Xi'an Tech. Full Simo Motor Co., Ltd., Jiangsu Xi'anda Explosion-proof Co., Ltd.,

Hangzhou Jiangchao Motor Co., Ltd., Shandong Huali Electric Motor Group Co., Ltd.,

CRRC Yongji Electric Co., Ltd., Zhejiang Jinlong Electrical Machinery STOCK Co.,

Ltd., Fuzhou Wonder Electric Co., Ltd., Nanyang Explosion Prevention Weite Co., Ltd.,

Shanxi Electric Motor Manufacturing Co., Ltd., Jiangsu Magnet Valley Technologies

Co., Ltd., Shanghai Testing & Inspection Institute for Electrical Equipment Co., Ltd.,

Suzhou Torin Drive Equipment Co., Ltd., Xiangtan Electric Manufacturing Group

Co.,Ltd., Zhuhai Kaibang Motor Manufacture Co., Ltd., Dongfang Electric Machinery

Co., Ltd., Jiangsu Aerospace Power Electromechanical Co., Ltd., Anhui Weineng

Electric Machinery Co., Ltd., Jiangmen Jiangsheng Electric Machine Works Co., Ltd.,

Siemens Standard Motors (China) Co., Ltd., Xuzhou Keya Electromechanical Co., Ltd.,

Shaoxing Motai Mechanical and Electrical Technology Co., Ltd., Kangfu Sci-tech Co.,

Ltd., Rongcheng Rongjia Power Co., Ltd.

1 Scope

This document applies to the classification of degrees of protection provided by

enclosures for rotating electrical machines. It defines the requirements for protective

enclosures that are in all other respects suitable for their intended use and which, from

the point of view of materials and workmanship, ensure that the properties dealt with

in this document are maintained under normal conditions of use.

2 Normative references

The following documents contain the provisions which, through normative reference in

this document, constitute the essential provisions of this document. For the dated

referenced documents, only the versions with the indicated dates are applicable to this

document; for the undated referenced documents, only the latest version (including all

the amendments) is applicable to this document.

IEC 60034-6 Rotating electrical machines - Part 6.Methods of cooling (IC code)

IEC 60079(all parts) Explosive atmospheres

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

A machine where no medium from the surrounding medium, for the purpose of cooling,

passes through the machine.

A machine with an open cooling circuit in which the coolant is drawn directly from the

surrounding medium passing through the machine and then returning directly to the

surrounding medium.

4 Designation

In this case, the degree of protection in either state of the

machine shall be indicated, for example IP55S/IP20M.

The absence of the letters S and M shall imply that the intended degree of protection

will be provided under all normal conditions of use.

5 Degrees of protection - First characteristic numeral

The term 'excluded' implies that a part of the body, a tool or a wire held by a person,

either will not enter the machine or, if it enters, that adequate clearance will be

maintained between it and the live parts or dangerous moving parts (smooth rotating

shafts and the like are not considered dangerous).

The blades and spokes of fans external to the enclosure shall be protected against

contact by means of guards complying with Table 1.

6 Degrees of protection - Second characteristic numeral

For second characteristic numerals up to and including 6, compliance of an enclosure

with an indicated degree of protection implies that the enclosure will also comply with

all lower degrees of protection in Table 3.

In consequence, the tests establishing these lower degrees of protection are not required,

except in case of doubt.

7 Marking

It is recommended that the characteristic letters and numerals be marked on the machine

preferably on the rating plate or, if this is not practicable, on the enclosure.

When all parts of a machine do not have the same degree of protection, at least the

designation of the lowest degree shall be shown, followed, if necessary, by the higher

designation with clear reference to the part to which it applies.

Space limitations on the rating plate usually only allow the lowest IP code to be marked.

8 General requirements for tests

Unless otherwise specified, the machine for each test shall be clean with all the parts in

place and mounted in the manner stated by the manufacturer.

For the purpose of the following test clauses in this document, the term "adequate

clearance" has the meaning given in 8.2.2 or 8.2.3.

The test device (sphere, finger, wire, etc.) does not touch the live parts or moving parts

other than non-dangerous parts such as smooth rotating shafts.

9 Tests for first characteristic numeral

Test and acceptance conditions for the first characteristic numeral are given in Table 4.

The dust test for numerals 5 and 6 shall be performed with the shaft stationary, provided

that the difference in pressure between running and stationary (caused by fan effects) is

lower than 2 kPa.

For tests on a low-voltage machine, a low-voltage supply (of not less than 40 V)

in series with a suitable lamp may be connected between the test finger and the

live parts inside the enclosure.

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