标准编号:	GB 4943.1-2011
中文名称:	信息技术设备 安全 第1部分：通用要求
英文名称:	Information technology equipment -Safety - Part 1: General requirements
中标分类:	L09    卫生、安全、劳动保护
行业分类:	GB    国家标准
ICS分类:	35.020 35.020    信息技术(IT)综合 35.020
发布机构:	中华人民共和国国家质量监督检验检疫总局 中国国家标准化管理委员会
发布日期:	2011-12-30
实施日期:	2012-12-1
标准状态:	被替代
被新标准替代:	GB 4943.1-2022 音视频、信息技术和通信技术设备 第1部分：安全要求
被替代日期:	2023-8-1
替代旧标准:	GB 4943-2001 信息技术设备的安全
翻译语言:	英文
文件格式:	PDF
中文字符数:	300000 字
翻译价格(元):	560.00 元
交付时间:	付款后 1 个工作日

Introduction



0 Principles of Safety



The following principles have been adopted in the development of this part of GB 4943.

These principles do not cover performance or functional characteristics of equipment.

0.1 General Principles of Safety



It is essential that designers understand the underlying principles of safety requirements in order that they can engineer safe equipment.

These principles are not an alternative to the detailed requirements of this part, but are intended to provide designers with an appreciation of the basis of these requirements. Where the equipment involves technologies and materials or methods of construction not specifically covered, the design of the equipment should provide a level of safety not less than those described in these principles of safety.

Designers shall take into account not only normal operating conditions of the equipment but also likely fault conditions, consequential faults, foreseeable misuse and external influences such as temperature, altitude, pollution, moisture, overvoltages on the MAINS SUPPLY and overvoltages on a TELECOMMUNICATION NETWORK or a CABLE DISTRIBUTION SYSTEM. Dimensioning of insulation spacings should take account of possible reductions by manufacturing tolerances, or where deformation could occur due to handling, shock and vibration likely to be encountered during manufacture, transport and normal use.

The following priorities should be observed in determining what design measures to adopt:

- where possible, specify design criteria that will eliminate, reduce or guard against hazards;

- where the above is not practicable because the functioning of the equipment would be impaired, specify the use of protective means independent of the equipment, such as personal protective equipment (which is not specified in this part);

- where neither of the above measures is practicable, or in addition to those measures, specify the provision of markings and instructions regarding the residual risks.

There are two types of persons whose safety needs to be considered, USERS (or OPERATORS) and SERVICE PERSONS.

USER is the term applied to all persons other than SERVICE PERSONS. Requirements for protection should assume that USERS are not trained to identify hazards, but will not intentionally create a hazardous situation. Consequently, the requirements will provide protection for cleaners and casual visitors as well as the assigned USERS. In general, USERS should not have access to hazardous parts, and to this end, such parts should only be in SERVICE ACCESS AREAS or in equipment located in RESTRICTED ACCESS LOCATIONS.

When USERS are admitted to RESTRICTED ACCESS LOCATIONS they shall be suitably instructed.

SERVICE PERSONS are expected to use their training and skill to avoid possible injury to themselves and others due to obvious hazards that exist in SERVICE ACCESS AREAS of the equipment or on equipment located in RESTRICTED ACCESS LOCATIONS. However, SERVICE PERSONS should be protected against unexpected hazards. This can be done by, for example, locating parts that need to be accessible for servicing away from electrical and mechanical hazards, providing shields to avoid accidental contact with hazardous parts, and providing labels or instructions to warn personnel about any residual risk.

Information about potential hazards can be marked on the equipment or provided with the equipment, depending on the likelihood and severity of injury, or made available for SERVICE PERSONS. In general, USERS shall not be exposed to hazards likely to cause injury, and information provided for USERS should primarily aim at avoiding misuse and situations likely to create hazards, such as connection to the wrong power source and replacement of fuses by incorrect types.

MOVABLE EQUIPMENT is considered to present a slightly increased risk of shock, due to possible extra strain on the supply cord leading to rupture of the earthing conductor. With HAND-HELD EQUIPMENT, this risk is increased; wear on the cord is more likely, and further hazards could arise if the units were dropped. TRANSPORTABLE EQUIPMENT introduces a further factor because it can be used and carried in any orientation; if a small metallic object enters an opening in the ENCLOSURE it can move around inside the equipment, possibly creating a hazard.

0.2 Hazards



Application of a safety standard is intended to reduce the risk of injury or damage due to the following:

- electric shock;

- energy related hazards;

- fire;

- heat related hazards;

- mechanical hazards;

- radiation;

- chemical hazards.

0.2.1 Electric shock

Electric shock is due to current passing through the human body. The resulting physiological effects depend on the value and duration of the current and the path it takes through the body. The value of the current depends on the applied voltage, the impedance of the source and the impedance of the body. The body impedance depends in turn on the area of contact, moisture in the area of contact and the applied voltage and frequency. Currents of approximately 0.5mA can cause a reaction in persons in good health and may cause injury indirectly due to involuntary reaction. Higher currents can have more direct effects, such as burn or muscle tetanization leading to inability to let go or to ventricular fibrillation.

Steady state voltages up to 42.4V peak, or 60V d.c., are not generally regarded as hazardous under dry conditions for an area of contact equivalent to a human hand. Bare parts that have to be touched or handled should be at earth potential or properly insulated.

Some equipment will be connected to telephone and other external networks. Some TELECOMMUNICATION NETWORKS operate with signals such as voice and ringing superimposed on a steady d.c. supply voltage; the total may exceed the values given above for steady-state voltages. It is common practice for the SERVICE PERSONS of telephone companies to handle parts of such circuits bare-handed. This has not caused serious injury, because of the use of cadenced ringing and because there are limited areas of contact with bare conductors normally handled by SERVICE PERSONS. However, the area of contact of a part accessible to the USER, and the likelihood of the part being touched, should be further limited (for example, by the shape and location of the part).

It is normal to provide two levels of protection for USERS to prevent electric shock. Therefore, the operation of equipment under normal conditions and after a single fault, including any consequential faults, should not create a shock hazard. However, provision of additional protective measures, such as protective earthing or SUPPLEMENTARY INSULATION, is not considered a substitute for, or a relief from, properly designed BASIC INSULATION.



Harm may result from: Examples of measures to reduce risks:

Contact with bare parts normally at HAZARDOUS VOLTAGES. Prevent USER access to parts at HAZARDOUS VOLTAGES by fixed or locked covers, SAFETY INTERLOCKS, etc. Discharge accessible capacitors that are at HAZARDOUS VOLTAGES.

Breakdown of insulation between parts normally at HAZARDOUS VOLTAGES and accessible conductive parts. Provide BASIC INSULATION and connect the accessible conductive parts and circuits to earth so that exposure to the voltage which can develop is limited because overcurrent protection will disconnect the parts having low impedance faults within a specified time; or provide a metal screen connected to protective earth between the parts, or provide DOUBLE INSULATION or REINFORCED INSULATION between the parts, so that breakdown to the accessible part is not likely to occur.

Contact with circuits connected to TELECOMMUNICATION NETWORKS that exceed 42.4 V peak or 60V d.c. Limit the accessibility and area of contact of such circuits, and separate them from unearthed parts to which access is not limited.

Breakdown of USER-accessible insulation. Insulation that is accessible to the USER should have adequate mechanical and electrical strength to reduce the likelihood of contact with HAZARDOUS VOLTAGES.

TOUCH CURRENT (leakage current) flowing from parts at HAZARDOUS VOLTAGES to accessible parts, or failure of a protective earthing connection. TOUCH CURRENT may include current due to EMC filter components connected between PRIMARY CIRCUITS and accessible parts. Limit TOUCH CURRENT to a specified value, or provide a high integrity protective earthing connection.



0.2.2 Energy related hazards

Injury or fire may result from a short-circuit between adjacent poles of high current supplies or high capacitance circuits, causing:

- burns;

- arcing;

- ejection of molten metal.

Even circuits whose voltages are safe to touch may be hazardous in this respect.

Examples of measures to reduce risks include:

- separation;

- shielding;

- provision of SAFETY INTERLOCKS.

0.2.3 Fire

Risk of fire may result from excessive temperatures either under normal operating conditions or due to overload, component failure, insulation breakdown or loose connections. Fires originating within the equipment should not spread beyond the immediate vicinity of the source of the fire, nor cause damage to the surroundings of the equipment.

Examples of measures to reduce risks include:

- providing overcurrent protection;

- using constructional materials having appropriate flammability properties for their purpose;

- selection of parts, components and consumable materials to avoid high temperature which might cause ignition;

- limiting the quantity of combustible materials used;

- shielding or separating combustible materials from likely ignition sources;

- using ENCLOSURES or barriers to limit the spread of fire within the equipment;

- using suitable materials for ENCLOSURES so as to reduce the likelihood of fire spreading from the equipment.

0.2.4 Heat related hazards

Injury may result from high temperatures under normal operating conditions, causing:

- burns due to contact with hot accessible parts;

- degradation of insulation and of safety-critical components;

- ignition of flammable liquids.

Examples of measures to reduce risks include:

- taking steps to avoid high temperature of accessible parts;

- avoiding temperatures above the ignition point of liquids;

- provision of markings to warn USERS where access to hot parts is unavoidable.

0.2.5 Mechanical hazards

Injury may result from:

- sharp edges and corners;

- moving parts that have the potential to cause injury;

- equipment instability;

- flying particles from imploding cathode ray tubes and exploding high pressure lamps.

Examples of measures to reduce risks include:

- rounding of sharp edges and corners;

- guarding;

- provision of SAFETY INTERLOCKS;

- providing sufficient stability to free-standing equipment;

- selecting cathode ray tubes and high pressure lamps that are resistant to implosion and explosion respectively;

- provision of markings to warn USERS where access is unavoidable.

0.2.6 Radiation

Injury to USERS and to SERVICE PERSONS may result from some forms of radiation emitted by equipment. Examples are sonic (acoustic), radio frequency, infra-red, ultraviolet and ionizing radiation, and high intensity visible and coherent light (lasers).

Examples of measures to reduce risks include:

- limiting the energy level of potential radiation sources;

- screening radiation sources;

- provision of SAFETY INTERLOCKS;

- provision of markings to warn USERS where exposure to the radiation hazard is unavoidable.

0.2.7 Chemical hazards

Injury may result from contact with some chemicals or from inhalation of their vapours and fumes.

Examples of measures to reduce risks include:

- avoiding the use of constructional and consumable materials likely to cause injury by contact or inhalation during intended and normal conditions of use;

- avoiding conditions likely to cause leakage or vaporization;

- provision of markings to warn USERS about the hazards.

0.3 Materials and Components



Materials and components used in the construction of equipment should be so selected and arranged that they can be expected to perform in a reliable manner for the anticipated life of the equipment without creating a hazard, and would not contribute significantly to the development of a serious fire hazard. Components should be selected so that they remain within their manufacturers' ratings under normal operating conditions, and do not create a hazard under fault conditions.



Information Technology Equipment—Safety—

Part 1: General Requirements



1 General



1.1 Scope



1.1.1 Equipment covered by this part

This part of GB 4943 is applicable to mains-powered or battery-powered information technology equipment, including electrical business equipment and associated equipment, with a RATED VOLTAGE not exceeding 600 V.

This part is also applicable to such information technology equipment:

- designed for use as telecommunication terminal equipment and TELECOMMUNICATION NETWORK infrastructure equipment, regardless of the source of power;

- designed and intended to be connected directly to, or used as infrastructure equipment in, a CABLE DISTRIBUTION SYSTEM, regardless of the source of power;

- designed to use the AC MAINS SUPPLY as a communication transmission medium (see Clause 6, Note 4 and 7.1, Note 4).

This part is also applicable to components and subassemblies intended for incorporation in information technology equipment. It is not expected that such components and subassemblies comply with every aspect of the part, provided that the complete information technology equipment, incorporating such components and subassemblies, does comply.

NOTE 1 Examples of aspects with which uninstalled components and subassemblies may not comply include the marking of the power rating and access to hazardous parts.

NOTE 2 This part may be applied to the electronic parts of equipment even if that equipment does not wholly fall within its Scope, such as large-scale air conditioning systems, fire detection systems and fire extinguishing systems. Different requirements may be necessary for some applications.

This part specifies requirements intended to reduce risks of fire, electric shock or injury for the OPERATOR and layman who may come into contact with the equipment and, where specifically stated, for a SERVICE PERSON.

This part is intended to reduce such risks with respect to installed equipment, whether it consists of a system of interconnected units or independent units, subject to installing, operating and maintaining the equipment in the manner prescribed by the manufacturer.

Examples of equipment that is in the scope of this standard are:

Generic product type Specific example of generic type

banking equipment monetary processing machines including automated teller (cash dispensing) machines (ATM)

data and text processing machines and associated equipment data preparation equipment, data processing equipment, data storage equipment, personal computers, plotters, printers, scanners, text processing equipment, visual display units

data network equipment bridges, data circuit terminating equipment, data terminal equipment, routers

electrical and electronic retail equipment cash registers, point of sale terminals including associated electronic scales

electrical and electronic office machines calculators, copying machines, dictation equipment, document shredding machines, duplicators, erasers, micrographic office equipment, motor-operated files, paper trimmers (punchers, cutting machines, separators), paper jogging machines, pencil sharpeners, staplers, typewriters

other information technology equipment photoprinting equipment, public information terminals, multimedia equipment

postage equipment mail processing machines, postage machines

telecommunication network infrastructure equipment billing equipment, multiplexers, network powering equipment, network terminating equipment, radio base stations, repeaters, transmission equipment, telecommunication switching equipment

telecommunication terminal equipment facsimile equipment, key telephone systems, modems, PABXs, pagers, telephone answering machines, telephone sets (wired and wireless)



NOTE 3 The requirements of GB 8898 may also be used to meet safety requirements for multimedia equipment. See IEC Guide 112, Guide on the safety of multimedia equipment.

This list is not intended to be comprehensive, and equipment that is not listed is not necessarily excluded from the Scope.

Equipment complying with the relevant requirements in this standard is considered suitable for use with process control equipment, automatic test equipment and similar systems requiring information processing facilities. However, this standard does not include requirements for performance or functional characteristics of equipment.

1.1.2 Additional requirements

Requirements additional to those specified in this standard may be necessary for:

- equipment intended for operation in special environments (for example, extremes of temperature; excessive dust, moisture or vibration; flammable gases; and corrosive or explosive atmospheres);

- electromedical applications with physical connections to the patient;

- equipment intended to be used in vehicles, on board ships or aircraft, at altitudes greater than 5 000 m;

- equipment intended for use where ingress of water is possible; for guidance on such requirements and on relevant testing, see Annex T.

NOTE Attention is drawn to the fact that authorities of some countries impose additional requirements.

1.1.3 Exclusions

This standard does not apply to:

- power supply systems which are not an integral part of the equipment, such as motor- generator sets, battery backup systems and transformers;

- building installation wiring;

- devices requiring no electric power.

1.2 Terms and Definitions



For the purpose of this Part the following definitions apply. Where the terms "voltage" and "current" are used, they imply the r.m.s. values, unless otherwise specified.

Definitions in alphabetical order of nouns

AREA, OPERATOR ACCESS 1.2.7.1

AREA, SERVICE ACCESS 1.2.7.2

BODY 1.2.7.5

CABLE, INTERCONNECTING 1.2.11.6

CABLE DISTRIBUTION SYSTEM 1.2.13.14

CHEESECLOTH 1.2.13.15

CIRCUIT, ELV 1.2.8.7

CIRCUIT, LIMITED CURRENT 1.2.8.9

CIRCUIT, PRIMARY 1.2.8.4

CIRCUIT, SECONDARY 1.2.8.5

CIRCUIT, SELV 1.2.8.8

CIRCUIT, TNV 1.2.8.11

CIRCUIT, TNV-1 1.2.8.12

CIRCUIT, TNV-2 1.2.8.13

CIRCUIT, TNV-3 1.2.8.14

CLEARANCE 1.2.10.1

CONDUCTOR, PROTECTIVE BONDING 1.2.13.11

CONDUCTOR, PROTECTIVE EARTHING 1.2.13.10

CORD, DETACHABLE POWER SUPPLY 1.2.5.5

CORD, NON-DETACHABLE POWER SUPPLY 1.2.5.6

CURRENT, PROTECTIVE CONDUCTOR 1.2.13.13

CREEPAGE DISTANCE 1.2.10.2

CURRENT, RATED 1.2.1.3

CURRENT, TOUCH 1.2.13.12

CUT-OUT, THERMAL 1.2.11.3

CUT-OUT, THERMAL, AUTOMATIC RESET 1.2.11.4

CUT-OUT, THERMAL, MANUAL RESET 1.2.11.5

EARTHING, FUNCTIONAL 1.2.13.9

ENCLOSURE 1.2.6.1

ENCLOSURE, ELECTRICAL 1.2.6.4

ENCLOSURE, FIRE 1.2.6.2

ENCLOSURE, MECHANICAL 1.2.6.3

ENERGY LEVEL, HAZARDOUS 1.2.8.10

EQUIPMENT, CLASS I 1.2.4.1

EQUIPMENT, CLASS II 1.2.4.2

EQUIPMENT, CLASS III 1.2.4.3

EQUIPMENT, DIRECT PLUG-IN 1.2.3.6

EQUIPMENT FOR BUILDING-IN 1.2.3.5

EQUIPMENT, HAND-HELD 1.2.3.2

EQUIPMENT, MOVABLE 1.2.3.1

EQUIPMENT, PERMANENTLY CONNECTED 1.2.5.4

EQUIPMENT, PLUGGABLE 1.2.5.3

EQUIPMENT, PLUGGABLE, TYPE A 1.2.5.1

EQUIPMENT, PLUGGABLE, TYPE B 1.2.5.2

EQUIPMENT, STATIONARY 1.2.3.4

EQUIPMENT, TRANSPORTABLE 1.2.3.3

FREQUENCY, RATED 1.2.1.4

INSULATION, BASIC 1.2.9.2

INSULATION, DOUBLE 1.2.9.4

INSULATION, FUNCTIONAL 1.2.9.1

INSULATION, REINFORCED 1.2.9.5

INSULATION, SOLID 1.2.10.4

INSULATION, SUPPLEMENTARY 1.2.9.3

INTERLOCK, SAFETY 1.2.7.6

LIMIT, EXPLOSION 1.2.12.15

LIMITER, TEMPERATURE 1.2.11.2

LOAD, NORMAL 1.2.2.1

LOCATION, RESTRICTED ACCESS 1.2.7.3

MATERIALS, FLAMMABILITY CLASSIFICATION 1.2.12.1

MATERIAL, 5VA CLASS 1.2.12.5

MATERIAL, 5VB CLASS 1.2.12.6

MATERIAL, HB40 CLASS 1.2.12.10

MATERIAL, HB75 CLASS 1.2.12.11

MATERIAL, HBF CLASS FOAMED 1.2.12.9

MATERIAL, HF-1 CLASS FOAMED 1.2.12.7

MATERIAL, HF-2 CLASS FOAMED 1.2.12.8

MATERIAL, V-0 CLASS 1.2.12.2

MATERIAL, V-1 CLASS 1.2.12.3

MATERIAL, V-2 CLASS 1.2.12.4

MATERIAL, VTM-0 CLASS 1.2.12.12

MATERIAL, VTM-1 CLASS 1.2.12.13

MATERIAL, VTM-2 CLASS 1.2.12.14

NETWORK, TELECOMMUNICATION 1.2.13.8

OPERATOR 1.2.13.7

PART, DECORATIVE 1.2.6.5

PERSON, SERVICE 1.2.13.5

RANGE, RATED FREQUENCY 1.2.1.5

RANGE, RATED VOLTAGE 1.2.1.2

RATING, PROTECTIVE CURRENT 1.2.13.17

SUPPLY, AC MAINS 1.2.8.1

SUPPLY, DC MAINS 1.2.8.2

SUPPLY, MAINS 1.2.8.3

SURFACE, BOUNDING 1.2.10.3

TEST, ROUTINE 1.2.13.3

TEST, SAMPLING 1.2.13.2

TEST, TYPE 1.2.13.1

THERMOSTAT 1.2.11.1

TIME, RATED OPERATING 1.2.2.2

TIME, RATED RESTING 1.2.2.3

TISSUE, WRAPPING 1.2.13.16

TOOL 1.2.7.4

USER 1.2.13.6

VOLTAGE, DC. 1.2.13.4

VOLTAGE, HAZARDOUS 1.2.8.6

VOLTAGE, MAINS TRANSIENT 1.2.9.10

VOLTAGE, PEAK WORKING 1.2.9.8

VOLTAGE, RATED 1.2.1.1

VOLTAGE, REQUIRED WITHSTAND 1.2.9.9

VOLTAGE, RMS WORKING 1.2.9.7

VOLTAGE, TELECOMMUNICATION NETWORK TRANSIENT 1.2.9.11

VOLTAGE, WORKING 1.2.9.6

1.2.1 Equipment electrical ratings

1.2.1.1

RATED VOLTAGE

supply voltage (for a three-phase AC MAINS SUPPLY, the line-to-line voltage) as declared by the manufacturer

Foreword I
Introduction VIII
0 Principles of Safety VIII
0.1 General Principles of Safety VIII
0.2 Hazards IX
0.3 Materials and Components XIV
1 General
1.1 Scope
1.2 Terms and Definitions
1.3 General Requirements
1.4 General Conditions for Tests
1.5 Components
1.6 Power Interface
1.7 Markings and Instructions
2 Protection from Hazards
2.1 Protection from Electric Shock and Energy Hazards
2.2 SELV Circuits
2.3 TNV Circuits
2.4 Limited Current Circuits
2.5 Limited Power Sources
2.6 Provisions for Earthing and Bonding
2.7 Overcurrent and Earth Fault Protection in Primary Circuits
2.8 Safety Interlocks
2.9 Electrical Insulation
2.10 Clearances, Creepage Distances and Distances through Insulation
3 Wiring, Connections and Supply
3.1 General
3.2 Connection to a Mains Supply
3.3 Wiring Terminals for Connection of External Conductors
3.4 Disconnection from the Mains Supply
3.5 Interconnection of Equipment
4 Physical Requirements
4.1 Stability
4.2 Mechanical Strength
4.3 Design and Construction
4.4 Protection against Hazardous Moving Parts
4.5 Thermal Requirements
4.6 Openings in Enclosures
4.7 Resistance to Fire
5 Electrical Requirements and Simulated Abnormal Conditions
5.1 Touch Current and Protective Conductor Current
5.2 Electric Strength
5.3 Abnormal Operating and Fault Conditions
6 Connection to Telecommunication Networks
6.1 Protection of Telecommunication Network Service Persons, and Users of Other Equipment Connected to the Network, from Hazards in the Equipment
6.2 Protection of Equipment Users from Overvoltages on Telecommunication Networks
6.3 Protection of the Telecommunication Wiring System from Overheating
7 Connection to Cable Distribution Systems
7.1 General
7.2 Protection of Cable Distribution System Service Persons, and Users of Other Equipment Connected to the System, from Hazardous Voltages in the Equipment
7.3 Protection of Equipment Users from Overvoltages on the Cable Distribution System
7.4 Insulation between Primary Circuits and Cable Distribution Systems
Annex A (Normative) Tests for Resistance to Heat and Fire
Annex B (Normative) Motor Tests Under Abnormal Conditions
Annex C (Normative) Transformers
Annex D (Normative) Measuring Instruments for Touch Current Tests
Annex E (Normative) Temperature Rise of A Winding
Annex F (Normative) Measurement of Clearances and Creepage Distances
Annex G (Normative) Alternative Method for Determining Minimum Clearances
Annex H (Normative) Ionizing Radiation
Annex J (Normative) Table of Electrochemical Potentials
Annex K (Normative) Thermal Controls
Annex L (Normative) Normal Load Conditions for Some Types of Electrical Business Equipment
Annex M (Normative) Criteria for Telephone Ringing Signals
Annex N (Normative) Impulse Test Generators
Annex P (Normative) Normative References
Annex Q (Normative) Voltage Dependent Resistors (VDRs)
Annex R (Informative) Examples of Requirements for Quality Control Programmes
Annex S (Informative) Procedure for Impulse Testing
Annex T (Informative) Guidance on Protection Against Ingress Of Water
Annex U (Normative) Insulated Winding Wires for Use Without Interleaved Insulation
Annex V (Normative) AC Power Distribution Systems
Annex W (Informative) Summation of Touch Currents
Annex X (Informative) Maximum Heating Effect in Transformer Tests
Annex Y (Normative) Ultraviolet Light Conditioning Test
Annex Z (Informative) Overvoltage Categories
Annex AA (Normative) Mandrel Test
Annex BB (Informative) Difference from GB 4943-
Annex CC (Informative) Comparison of Normative References/ Bibliography between IEC 60950-1:2005 and This Part
Annex DD (Normative) Instruction on New Safety Warning Sign in the Standard
Annex EE (Informative) Cross-reference of the Safety-Related Description Examples Written in Chinese, Tibetan, Mongolian, Zhuang and Uyghur languages .
Bibliography
Figure 2A Test Finger
Figure 2B Test Pin
Figure 2C Test Probe
Figure 2D Accessibility of Internal Conductive Parts
Figure 2E Voltages in SELV Circuits under Single Fault Conditions
Figure 2F Maximum Voltages Permitted after a Single Fault
Figure 2G Test Generator
Figure 2H Examples of Application of Insulation
Figure 2J Thermal Ageing Time
Figure 2K Abrasion Resistance Test for Coating Layers
Figure 4A Impact Test Using a Steel Ball
Figure 4B Examples of Cross-sections of Designs of Openings Preventing Vertical Access
Figure 4C Examples of Louvre Design
Figure 4D Enclosure Openings
Figure 4E Typical Bottom of a Fire Enclosure for Partially Enclosed Component or Assembly
Figure 4F Baffle Plate Construction
Figure 5A Test Circuit for Touch Current of Single-phase Equipment on a Star TN or TT Power Supply System
Figure 5B Test Circuit for Touch Current of Three-phase Equipment on a Star TN or TT Power Supply System
Figure 6A Test for Separation between a Telecommunication Network and Earth
Figure 6B Application Points of Test Voltage
Figure B.1 Determination of Arithmetic Average Temperature
Figure C.1 Determination of Arithmetic Average Temperature
Figure D.1 Measuring Instrument
Figure D.2 Alternative Measuring Instrument
Figure F.1 Narrow Groove
Figure F.2 Wide Groove
Figure F.3 V-shaped Groove
Figure F.4 Rib
Figure F.5 Uncemented Joint with Narrow Groove
Figure F.6 Uncemented Joint with Wide Groove
Figure F.7 Uncemented Joint with Narrow and Wide Grooves
Figure F.8 Narrow Recess
Figure F.9 Wide Recess
Figure F.10 Coating around Terminals
Figure F.11 Coating over Printed Wiring
Figure F.12 Measurements through Openings in Enclosures
Figure F.13 Intervening, Unconnected Conductive Part
Figure F.14 Solid Insulating Material
Figure F.15 Thin Sheet Insulating Material
Figure F.16 Cemented Joints in Multi-Layer Printed Board
Figure F.17 Component Filled with Insulating Compound
Figure F.18 Partitioned Bobbin
Figure M.1 Definition of Ringing Period and Cadence Cycle
Figure M.2 ITS1 Limit Curve for Cadenced Ringing Signal
Figure M.3 Peak and Peak-To-Peak Currents
Figure M.4 Ringing Voltage Trip Criteria
Figure N.1 ITU-T Impulse Test Generator Circuit
Figure N.2 GB 8898 Impulse Test Generator Circuit
Figure S.1 Waveform on Insulation Without Surge Suppressors and No Breakdown
Figure S.2 Waveforms on Insulation During Breakdown Without Surge Suppressors
Figure S.3 Waveforms on Insulation With Surge Suppressors in Operation
Figure S.4 Waveform on Short-Circuited Surge Suppressor and Insulation
Figure V.1 Examples of TN-S Power Distribution Systems
Figure V.2 Example of TN-C-S Power Distribution System
Figure V.3 Example of TN-C Power Distribution System
Figure V.4 Example of Single-Phase, Three-Wire TN-C Power Distribution System
Figure V.5 Example of Three Line and Neutral TT Power Distribution System
Figure V.6 Example of Three Line TT Power Distribution System
Figure V.7 Example of Three Line (and Neutral) IT Power Distribution System
Figure V.8 Example of Three Line IT Power Distribution System
Figure W.1 Touch Current from A Floating Circuit
Figure W.2 Touch Current from An Earthed Circuit
Figure W.3 Summation of Touch Currents in a PABX
Figure AA.1 Mandrel
Figure AA.2 Initial Position of Mandrel
Figure AA.3 Final Position of Mandrel
Figure AA.4 Position of Metal Foil on Insulating Material
Table 1A Voltage Ranges of SELV and TNV Circuits
Table 1B Equivalence of Flammability Classes
Table 1C Capacitor Ratings According to GB/T
Table 1D Informative Examples of Application of Capacitors
Table 2A Distance through Insulation of Internal Wiring
Table 2B Limits for Power Sources without an Overcurrent Protective Device
Table 2C Limits for Power Sources with an Overcurrent Protective Device
Table 2D Minimum Size of Protective Bonding Conductors
Table 2E Test Duration, a.c. Mains Supplies
Table 2F Examples of Protective Devices in Single-Phase Equipment or Subassemblies
Table 2G Examples of Protective Devices in Three-Phase Equipment
Table 2H Examples of Application of Insulation
Table 2J AC Mains Transient Voltages
Table 2K Minimum Clearances for Insulation in Primary Circuits and between Primary and Secondary Circuits (Applicable to Those to be Operated below 2 000 m above the Sea Level)
Table 2L Additional Clearances in Primary Circuits (Applicable to Those to be Operated below 2 000 m above the Sea Level)
Table 2M Minimum Clearances in Secondary Circuits (Applicable to Those to be Operated below 2 000 m above Sea Level)
Table 2N Minimum Creepage Distances
Table 2P Tests for Insulation in Non-separable Layers
Table 2Q Minimum Separation Distances for Coated Printed Boards
Table 2R Insulation in Printed Boards
Table 3A Sizes of Cables and Conduits for Equipment Having a Rated Current not Exceeding 16 A
Table 3B Sizes of Conductors
Table 3C Physical Tests on Power Supply Cords
Table 3D Range of Conductor Sizes to be Accepted by Terminals
Table 3E Sizes of Terminals for Mains Supply Conductors and Protective Earthing Conductors a
Table 4A Minimum Property Retention Limits after UV Exposure
Table 4B Temperature Limits, Materials and Components
Table 4C Touch Temperature Limits
Table 4D Size and Spacing of Openings in Metal Bottoms of Fire Enclosures
Table 4E Summary of Material Flammability Requirements
Table 5A Maximum Current
Table 5B Test Voltages for Electric Strength Tests Based on Peak Working Voltages
Table 5C Test Voltages for Electric Strength Tests Based on Required Withstand Voltages
Table 5D Temperature Limits for Overload Conditions
Table B.1 Temperature Limits for Motor Windings (Except for Running Overload Test)
Table B.2 Permitted Temperature Limits for Running Overload Tests
Table C.1 Temperature Limits for Transformer Windings
Table F.1 Value of X
Table G.1 AC Mains Transient Voltages
Table G.2 Minimum Clearances up to 2 000 m Above Sea Level
Table J.1 Electrochemical Potentials (V)
Table N.1 Component values for Figures N.1 and N
Table R.1 Rules for Sampling and Inspection—Coated Printed Boards
Table R.2 Rules for Sampling and Inspection—Reduced Clearances
Table T.1 Extract from GB
Table U.1 Mandrel Diameter
Table U.2 Oven Temperature
Table X.1 Test Steps
Table Z.1 Overvoltage Categories

引 言




0 安全的原则

GB 4943的本部分制定时采用了以下原则。 这些原则不涉及设备的性能及功能特性。
0.1 安全的总则
为了设计出安全的设备，设计者必须了解安全要求的基本原则。 这些原则不能代替本部分的详细要求，只是让设计者了解这些要求所依据的原则。如果设备涉
及的技术、材料或结构方式未明确规定，那么设备的设计应当至少达到本安全原则所述的安全等级。 设计者不仅要考虑设备的正常工作条件，还要考虑可能的故障条件以及随之引起的故障，可预
见的误用以及诸如温度、海拔、污染、湿度、电网电源的过电压和通信网络或电缆分配系统的过电 压等外界影响。还应当考虑由于制造误差或在制造、运输和正常使用中由于搬运、冲击和震动引起 的变形而可能发生的绝缘间距的减小。
在确定采用何种设计方案时，应当遵守以下的优先次序：
—— 如果可能，规定能消除、减小危险或对危险进行防护的设计原则；
—— 如果实行以上原则将削弱设备的功能，那么应当使用独立于设备的保护措施，如人身保 护设备（本部分未作规定）；
—— 如果上述方案和其它的措施均不切实可行，那么应当对残留的危险采取标识和说明的措 施。
需要考虑两类人员的安全，一类是使用人员（或操作人员），另一类是维修人员。
使用人员是指除维修人员以外的所有人员。安全保护要求是假定使用人员未经过如何识别危险 的培训，但不会故意制造危险状况而提出的。因而，这些要求除了为指定的使用人员提供保护外， 也为卫生清扫人员和临时来访人员提供保护。通常，应当限制使用人员接触危险零部件，为此，此 类零部件应当仅位于维修人员接触区域内或位于受限制接触区内的设备内。
如果允许使用人员进入受限制接触区，则应当予以适当指导。 维修人员是指当设备中的维修接触区域或处在受限制接触区内的设备存在明显危险时，可以运
用他们所受的训练和技能避免可能的、对自己或他人伤害的专业人员。但是，应当对维修人员就意 外危险进行防护，可以通过以下方法进行，例如，把维修时需要接触的零部件的安置远离电气和机 械危险，设置屏蔽以避免意外接触危险零部件，用标牌或警告说明以提醒维修人员有残留的危险。 潜在危险的信息可以根据其造成伤害的可能性和严重程度在设备上标示或随设备一起提供，或 者使维修人员能得到。通常，使用人员不应处于可能造成伤害的危险中，因此提供给用户的信息主
要在于避免误用和可能造成危险的状况，例如错误连接电源和用型号不正确的熔断器进行替换。
对移动式设备，由于其电源线可能会承受额外的应力，从而导致保护接地导体断裂，故会增加 电击的危险。对手持式设备，其电源线受磨损的机会较多，这种危险性更大，假如设备跌落过，可 能会产生更严重的危险。可携带式设备因为其可能在任何方向使用和携带，所以又增加了危险系数； 如果一个小金属物进入外壳上的开孔，它可能在设备内活动，很可能导致危险。
0.2 危险
应用安全标准的目的在于减少由于下列各种危险造成伤害或危害的危险：
—— 电击；




—— 与能量有关的危险；
—— 着火；
—— 与热有关的危险；
—— 机械危险；
—— 辐射；
—— 化学危险。
0.2.1 电击
电击是由于电流通过人体而造成的，其引起的生理反应取决于电流值的大小和持续时间及其通 过人体的路径。电流值取决于施加的电压以及电源的阻抗和人体的阻抗。人体的阻抗依次取决于接 触面积、接触区域的湿度及施加的电压和频率。大约0.5mA的电流就能在健康的人体内产生反应，而 且这种不知不觉的反应可能会导致间接的伤害。电流再大些，就会产生直接的影响，例如烧伤、肌 肉痉挛导致无法摆脱或心室的纤维性颤动。
在干燥条件下，相当于人的一只手的接触面积上，峰值电压高达42.4V或直流电压高达60V的稳 态电压，一般不认为是危险电压。但是，对使用时必须接触的或用手操作的裸露零部件，则应当使
其处于地电位，或者对其采取适当的隔离。 有些设备预定要与电话和其它外部网络连接，而有些通信网络工作时信号（如声音或振铃）叠
加在稳定的直流电源电压上，其总和将超过上述的稳态电压值；而电话公司的维修人员经常直接用 手操作这种电路的零部件，但并未导致严重伤害，这是因为使用的是有节奏的振铃信号，而且由维 修人员用手操作的裸露导体的接触区域通常是有限的。但是，使用人员可接触零部件的区域和接触
零部件的可能性应当进一步限制（例如通过零部件的形状和安装位置）。
为了防止使用人员遭到电击，通常要具有两级保护。因此，设备在正常工作条件下和在单一故 障（包括随之引起的其它故障）状态下运行都不会引起电击危险。然而，附加的保护措施（如保护 接地或附加绝缘）不能用来取代设计完好的基本绝缘，或降低对基本绝缘的要求。

可能造成伤害的原因 减小危险的方法示例

接触正常情况下带危险电压的裸 露零部件。

用固定的或锁紧的盖、安全联锁装置等防止 使用人员接触带危险电压的零部件；使可触及的带 危险电压的电容器放电。




正常情况下带危险电压的零部件
和可触及的导电零部件间的绝缘被击穿。

采用基本绝缘并把可触及的导电零部件和电
路接地，这样，由于过流保护装置在规定时间内断 开发生低阻抗故障的零部件，使接触危险电压的可
接触性受到限制；或者在零部件间安装一个与保护 地相连的金属屏蔽，或者在零部件间采用双重绝缘 或加强绝缘，以便使可触及零部件间的绝缘不会被 击穿。




接触与峰值电压超过42.4V或直流
电压超过60V的通信网络连接的电路。

限制这种电路的可触及性和接触区域，把它们
与未接地的、接触不受限制的零部件隔离开。



使用人员可触及绝缘被击穿。 使用人员可触及的绝缘应当有足够的机械强
度和电气强度以减少与危险电压接触的可能性。





从带危险电压的零部件流向可触及
零部件的接触电流（泄漏电流），或保护 接地连接失效。接触电流可包括接在一 次电路和可触及零部件之间的电磁兼容
（EMC）滤波组件所产生的电流。
0.2.2 与能量有关的危险

把接触电流限制在规定值内，或提供更可靠的
保护接地连接。

大电流电源或大电容电路的相邻电极间短路时可能导致伤害或着火，其原因是：
—— 燃烧；
—— 起弧；
—— 溢出熔融金属。 就此而论，甚至接触带安全电压的电路也可能是危险的。 减小这种危险的方法包括：
—— 隔离；
—— 屏蔽；
—— 使用安全联锁装置。
0.2.3 着火
正常工作条件下过载、元器件失效、绝缘击穿或连接松动都可能产生导致着火危险的过高温度。 但是，应当保证设备内着火点产生的火焰不会蔓延到火源近区以外，也不会对设备的周围造成损害。
减小这种危险的方法包括：
—— 提供过流保护装置；
—— 使用符合要求的适当燃烧特性的结构材料；
—— 选择的零部件、元器件和消耗材料能避免产生可能引起着火的高温；
—— 限制易燃材料的用量；
—— 把易燃材料与可能的点燃源屏蔽或隔离；
—— 使用防护外壳或挡板，以限制火焰只在设备内部蔓延；
—— 使用合适的材料制作外壳，以减小火焰向设备外蔓延的可能性。
0.2.4 与热有关的危险
正常工作条件下的高温可能造成伤害，其原因是：
—— 接触烫热的可触及零部件引起灼伤；
—— 绝缘等级下降和安全元器件性能降低；
—— 引燃可燃液体。 减小这种危险的方法包括：
—— 采取措施避免可触及零部件产生高温；
—— 避免使温度高于液体的引燃点；
—— 如果不可避免接触烫热的零部件，提供警告标识以告诫使用人员。
0.2.5 机械危险
可能导致伤害的原因是：
—— 尖锐的棱缘和拐角；
—— 可能潜在地引起危害的运动零部件；
—— 设备的不稳定性；
—— 内爆的阴极射线管和爆裂的高压灯产生的碎片。 减小这种危险的方法包括：
—— 倒圆尖锐的棱缘和拐角；
—— 配备防护装置；




—— 使用安全联锁装置；
—— 使落地式设备有足够的稳定性；
—— 选择能抗内爆的阴极射线管和耐爆裂的高压灯；
—— 在不可避免接触时，提供警告标识以告诫使用人员。
0.2.6 辐射
设备产生的某种形式的辐射会对使用人员和维修人员造成伤害，辐射的示例可以是声波（音频） 辐射，射频辐射，红外线、紫外线和电离辐射，以及高强度可见光和相干光（激光）辐射。
减小这种危险的方法包括：
—— 限制潜在辐射源的能量等级；
—— 屏蔽辐射源；
—— 使用安全联锁装置；
—— 如果不可避免暴露于辐射危险中，要提供警告标识以告诫使用人员。
0.2.7 化学危险
接触某些化学物品或吸入它们的气体和烟雾可能会造成伤害。 减小这种危险的方法包括：
──避免使用在预定的和正常条件下使用设备时由于接触或吸入可能造成伤害的堆积的和消耗 性的材料；
──避免可能产生泄漏或气化的条件；
──提供警告标识以告诫使用人员危险。
0.3 材料和元器件
设备结构所使用的材料和元器件应当适当选择和合理配置，以便使设备在预定寿命期间安全可 靠地运行，不会产生危险，而且在出现严重着火危险时，不会加剧火焰的蔓延。选择的元器件应当 在正常工作条件下保持在制造厂商设定的额定值内，在故障条件下也不会产生危险。




信息技术设备的安全
第1部分：通用要求


1 总则

1.1 范围
1.1.1 本部分适用的设备
GB 4943的本部分适用于电网电源供电的或电池供电的、额定电压不超过600V的信息技术设备， 包括电气事务设备和与之相关的设备。
本部分也适用于如下的信息技术设备：
—— 设计用来作为通信终端设备和通信网络基础设备，不考虑供电的方式；
—— 设计和预定直接连接到或作为基础设备用在电缆分配系统的设备，不考虑供电的方式；
—— 设计使用交流电网电源作为信息传输媒介（见第6章的注4和7.1的注4）。 本部分也适用于预定安装在信息技术设备内部的元器件和组件。如果安装有这些元器件和组件
的完整的信息技术设备符合本部分的要求，那么不要求这些元器件或组件符合本部分的所有要求。
注 1：有关未安装的元器件和组件可以不符合的示例包括电源铭牌和接触危险零部件的标识。
注 2：如果设备不完全在本部分范围内，例如大型空调系统，火情探测系统和灭火系统，但设备的电气部分可 适用于本部分。对某些场合，必须有不同的要求。
本部分规定的一系列要求是为了减小操作人员和可能与设备接触的外行人员遭受着火、电击或 伤害的危险。当特殊说明时，也包括维修人员。
本部分旨在减小被安装的设备在按制造厂商所规定的方法进行安装、操作和维修时的危险。被 安装的设备可以是由若干设备单元互连而成的系统，也可以是由若干独立的设备组成的系统。
属于本部分范围内的设备示例如下：

普通的产品类别 各类别产品的详细示例
银行设备 货币处理机，包括自动出纳（现金分发）机（ATM）
数据和文本处理机及相关设
备 数据预处理设备，数据处理设备，数据存储设备，个人计
算机，绘图仪，打印机，扫描仪，文本处理设备，直观显示装 置
数据网络设备 网桥，数据电路终端设备，数据终端设备，路由器
电子和电气零售设备 现金出纳机，销售点终端机（包括相关的电子秤）
电子和电气办公机器 计算器，复印机，听写设备，碎纸机，复制机，消磁器，
显微办公设备，电动文卷输送机，文件修整机（包括打孔机、 切割机、分类机），文件整理机，削铅笔器，订书机，打字机
其它信息技术设备 照片打印设备，公共信息终端，多媒体设备
邮资设备 邮件处理机，邮资机
通信网络基础设备 票据设备，多路调制（转换）器，网络供电设备，网络终
端设备，无线基站，转发器（中继站），传输设备，通信转换 设备
通信终端设备 传真机，按键电话系统，调制解调器，自动用户交换机
（PABXs），寻呼机，电话应答机，电话机（有线的和无线的）
注3：GB 8898中的要求可能也用来作为多媒体设备需要满足的安全要求。参见IEC指南112：多媒体设备的安全




导则。
这里所列举的设备并未包括所有的设备，因此未列出的设备并不一定不在本部分的范围内。 符合本部分有关要求的设备就可以认为该设备能与需要信息处理的过程控制设备、自动试验设
备以及类似系统配合使用。但是，本部分不包括设备的性能或功能特性的要求。
1.1.2 附加要求
对于下列设备，可能需要在本部分所规定的安全要求以外附加要求：
—— 预定要在特殊环境条件（例如极高或极低温度，过量粉尘、湿气或振动，可燃气体、腐 蚀或易爆环境等）下工作的设备；
—— 与患者人体直接连接的医用电子设备；
—— 预定要在车辆、船舶或飞机上使用的设备，在海拔 5000m 以上高原使用的设备；
—— 预定在可能会进水的场合使用的设备，对这些设备的要求及相关的试验的应用指南见附
录 T。
注： 应当注意有某些国家主管部门要求有附加要求。
1.1.3 不适用的设备
本部分不适用于：
—— 不与设备构成一体的电源供电系统，例如电动机发电机组、电池备用系统和变压器；
—— 建筑物安装配线；
—— 不需要电源的装置。




接触电流 1.2.13.12
热断路器 1.2.11.3
自动复位热断路器 1.2.11.4
手动复位热断路器 1.2.11.5
功能接地 1.2.13.9
防护外壳 1.2.6.1
电气防护外壳 1.2.6.4
防火防护外壳 1.2.6.2
机械防护外壳 1.2.6.3
危险能量等级 1.2.8.10
I类设备 1.2.4.1
Ⅱ类设备 1.2.4.2
Ⅲ类设备 1.2.4.3
直接插入式设备 1.2.3.6
嵌装式设备 1.2.3.5
手持式设备 1.2.3.2
移动式设备 1.2.3.1
永久性连接式设备 1.2.5.4
可插式设备 1.2.5.3
A型可插式设备 1.2.5.1
B型可插式设备 1.2.5.2
驻立式设备 1.2.3.4
可携带式设备 1.2.3.3
额定频率 1.2.1.4
基本绝缘 1.2.9.2
双重绝缘 1.2.9.4
功能绝缘 1.2.9.1
加强绝缘 1.2.9.5
固体绝缘 1.2.10.4
附加绝缘 1.2.9.3
安全联锁装置 1.2.7.6
燃爆限值 1.2.12.15
限温器 1.2.11.2
正常负载 1.2.2.1
受限制接触区 1.2.7.3
材料的可燃性分级 1.2.12.1
5VA级材料 1.2.12.5
5VB级材料 1.2.12.6
HB40级材料 1.2.12.10
HB75级材料 1.2.12.11
HBF级泡沫材料 1.2.12.9
HF—1级泡沫材料 1.2.12.7
HF—2级泡沫材料 1.2.12.8




V—0级材料 1.2.12.2
V—1级材料 1.2.12.3
V—2级材料 1.2.12.4
VTM—0级材料 1.2.12.12
VTM—1级材料 1.2.12.13
VTM—2级材料 1.2.12.14
通信网络 1.2.13.8
操作人员 1.2.13.7
装饰件 1.2.6.5
维修人员 1.2.13.5
额定频率范围 1.2.1.5
额定电压范围 1.2.1.2
保护电流额定值 1.2.13.17
交流电网电源 1.2.8.1
直流电网电源 1.2.8.2
电网电源 1.2.8.3
防护界面 1.2.10.3
例行试验 1.2.13.3
抽样试验 1.2.13.2
型式试验 1.2.13.1
恒温器 1.2.11.1
额定工作时间 1.2.2.2
额定间歇时间 1.2.2.3
包装用薄棉纸 1.2.13.16
工具 1.2.7.4
使用人员 1.2.13.6
直流电压 1.2.13.4
危险电压 1.2.8.6
电网电源瞬态电压 1.2.9.10
峰值工作电压 1.2.9.8
额定电压 1.2.1.1
要求的耐压 1.2.9.9
有效值工作电压 1.2.9.7
通信网络瞬态电压 1.2.9.11
工作电压 1.2.9.6
1.2.1 设备电气额定值
1.2.1.1
额定电压 rated voltage
由制造厂商标定的电源电压（对三相交流电网电源，指线间电压）。
1.2.1.2
额定电压范围 rated voltage range
由制造厂商标定的电源电压范围，用上限额定电压和下限额定电压表示。
1.2.1.3
额定电流 rated current




由制造厂商标定的设备输入电流。
1.2.1.4
额定频率 rated frequency
由制造厂商标定的电源频率。
1.2.1.5
额定频率范围 rated frequency range
由制造厂商标定的电源频率范围，用该频率范围的上限额定频率和下限额定频率来表示。
1.2.2 工作条件
1.2.2.1
正常负载 normal load
为了测试目的使用的一种工作状态，可以尽可能地代表能合理预计到的正常使用时最严酷的条 件。
如果合理预计到的实际使用时的条件比制造商推荐的最大负载条件更严酷时，包括额定工作时 间和额定间歇时间，则要采用能代表最严酷条件的工作状态。
注： 附录L列出了某些类设备的正常负载条件。
1.2.2.2
额定工作时间 rated operating time
由制造厂商为设备规定的最长工作时间。
1.2.2.3
额定间歇时间 rated resting time
由制造厂商规定的在设备的额定工作时间的周期之间关断或空转的最短时间。
1.2.3 设备移动性
1.2.3.1
移动式设备 movable equipment
下列之一的设备：
—— 质量小于或等于 18kg 且未固定的设备，或者
—— 装有滚轮、小脚轮或其它装置，便于操作人员按完成预定应用的需要来移动的设备。
1.2.3.2
手持式设备 hand-held equipment
在正常使用时要用手握持的移动式设备或任何类型设备的一个部件。
1.2.3.3
可携带式设备 transportable equipment
预定可由使用人员经常携带的可移动式设备。
注：示例包括膝上型和笔记本型个人计算机，手写输入计算机以及他们的便携式附件，如打印机和CD-ROM驱动
器。
1.2.3.4
驻立式设备 stationary equipment
不可移动的设备。
1.2.3.5
嵌装式设备 equipment for building-in
预定安装在预先准备好的凹座内的设备，例如装在墙壁内或类似安装位置内的设备。
注： 通常，嵌装式设备并不是所有的侧面都具有外壳，因为在安装好之后，有的侧面就得到了保护。




直接插入式设备 direct plug-in equipment
预定使用中不使用电源线，电源插头和设备外壳构成一整体、其重量是靠墙上插座来承载的设 备。
1.2.4 设备的防电击保护类别
注： 有些信息技术设备不能确认为符合下列任何一种类别。
1.2.4.1
I 类设备 class I equipment
用下列方法来获得防电击保护性能的设备：
—— 采用基本绝缘，而且
—— 还要装有一种连接装置，使那些在基本绝缘一旦失效就会带危险电压的导电零部件与建 筑物配线中的保护接地导体相连。
注： I类设备可以有带双重绝缘和加强绝缘的零部件。
1.2.4.2
Ⅱ类设备 class Ⅱ equipment
防电击保护不仅依靠基本绝缘，而且还采取附加安全保护措施的设备（ 例如采用双重绝缘或加 强绝缘的设备），这类设备不依靠保护接地。
1.2.4.3
Ⅲ类设备 class Ⅲ equipment
防电击保护是依靠安全特低电压（SELV）电路供电来实现的，且不会产生危险电压的设备。
注： 对Ⅲ类设备，虽然没有防电击要求，但本部分的其它要求都适用。
1.2.5 与电源连接的方式
1.2.5.1
A 型可插式设备 pluggable equipment type A
预定要通过非工业用插头和插座，或通过非工业用器具耦合器，或者通过这两者与电网电源连 接的设备。
1.2.5.2
B 型可插式设备 pluggable equipment type B
预定要通过符合GB/T 11918或类似的国家标准的工业用插头和插座或通过工业用器具耦合器， 或者通过这两者与电网电源连接的设备。
1.2.5.3
可插式设备 pluggable equipment
A型可插式设备或B型可插式设备。
1.2.5.4
永久性连接式设备 permanently connected equipment
预定要用螺钉接线端子或其它可靠方法与建筑物安装配线连接的设备。
1.2.5.5
可拆卸的电源软线 detachable power supply cord
预定要利用适当的器具耦合器与设备连接，用以供电的软线。
1.2.5.6
不可拆卸的电源软线 non-detachable power supply cord 固定在设备上的或与设备装配在一起的用以供电的软线。 这种软线可以有：
普通软线：无需使用特殊制备的软线或专用工具就能很容易地进行更换的软线；或




专用软线：特殊制备的或需使用专门设计的工具来进行更换的软线，或者不损伤设备就不能进
行更换的软线。 “特殊制备”一词是指配有一体化软线护套，采用电缆耳片、成形环片等，但不是指在接到接
线端子之前对导线重新加以成形，也不是指为使多股导线端部紧密而对多股导线加以拧紧。
1.2.6 外壳
1.2.6.1
外壳 enclosure
具有1.2.6.2、1.2.6.3或1.2.6.4所规定的一种或多种功能的设备的一个部件。
注： 一种类型的外壳可以在另一种类型的外壳里面。（例如：电气防护外壳在防火防护外壳里面，或防火防
护外壳在电气防护外壳里面）。另外，一种外壳可以提供多种类型外壳的功能（例如：兼有电气防护外壳 和防火防护外壳的功能）。
1.2.6.2
防火防护外壳 fire enclosure
用来使设备内发生的着火或火焰的蔓延减小到最低限度的设备部件。
1.2.6.3
机械防护外壳 mechanical enclosure
用来减小由机械危险和其它物理危险造成伤害的危险的设备部件。