This standard specifies the general safety requirements for electrical equipment for professional, industrial process and educational use, including equipment and computing devices for the following purposes: measurement and testing; control; laboratory use; accessories used with the above equipment and devices (such as sample handling equipment). This standard applies to equipment defined in the following items and used in the specified environment: A) Electrical measuring and test equipment refers to equipment that measures, indicates or records one or more electrical or non-electrical quantities by electrical methods, and also includes non-measuring equipment such as signal generators, measurement standards, power supplies, transducers and transmitters. B) Electrical control equipment refers to equipment that controls one or more output quantities to specified values. Each specified value can be set manually, locally or remotely programmed, or controlled by one or more input variables. C) Electrical laboratory equipment Equipment that measures, indicates, monitors or analyzes substances or is used to prepare materials. This equipment can also be used outside the laboratory. This standard applies to equipment that can be used safely under at least the following environmental conditions: -- Indoor use; -- Altitude below 2000m, or above 2000m as specified by the manufacturer (see Chapter D9); -- Temperature within the range of 5℃ to 40℃; -- Maximum relative humidity is 80% when the temperature is below 31℃; Relative humidity decreases linearly to 50% when the temperature is 40℃; -- Power supply voltage fluctuation should not exceed ±10% of the nominal voltage; -- Other power supply voltage fluctuations should be in accordance with the manufacturer's regulations; -- Transient overvoltage is facility category (overvoltage category) Ⅰ, Ⅱ (see Appendix J), and for power supply, the minimum and normal category is Ⅱ; -- Pollution degree is 1 or 2, see 3.7.3 of IEC 664 "Insulation coordination of low-voltage systems, including electrical clearances and creepage distances of equipment". 1.1 This standard does not include: reliable function, performance or other characteristics of equipment; maintenance (repair); protection of maintenance (repair) personnel. 1.2 Equipment not included in the scope of this standard: - electrical equipment, such as power electronic equipment; - machine tools and machine tool controls (see IEC 204 "Electrical Equipment of Industrial Establishments"); - 0.5, 1 and 2 class AC Watt-hour meters (see IEC 521 "0.5, 1 and 2 class AC Watt-hour meters"); - medical electrical equipment falling within the scope of IEC 601 "Medical Electrical Equipment"; - bio-amplifiers that connect equipment to the human body within the scope of research or education; - type tests and part type test assemblies of low-voltage switchgear and controlgear (see IEC 439-1 "Low-voltage switchgear and controlgear assemblies Part 1: Type tests and part type test assemblies"); - circuits and equipment forming part of the electrical installation of a building (see IEC 364 "Electrical Installations of Buildings"); - computers, processors and similar devices, except for the equipment specified in clause 1.3 (see IEC 950 "Safety of Information Technology Equipment (including Electrical Business Equipment)"); - Transformers separated from equipment (see IEC 742 "Requirements for Isolation Transformers and Safety Isolation Transformers"); - Household equipment (see IEC 335 "Safety of Household and Similar Electrical Appliances"); - Equipment used in explosive atmospheres (see IEC 79 "Electrical Equipment in Explosive Gases"). 1.3 This standard applies only to computers, processors, etc. that form part of the equipment within the scope of this standard or are designed to be used only with the equipment. GB 4793.1-1995 Safety requirements for electrical equipment for measurement, control and laboratory use Part 1: General requirements GB4793.1-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Safety requirements for electrical equipment for measurement, control, and laboratory use
Part 1: General requirements
GB 4793.1-1995
IEC 1010-1: 1990
Replaces GB 4793--84
This standard is equivalent to the international standard IEC1010-1:1990 "Safety requirements for electrical equipment for measurement, control, and laboratory use Part 1: General requirements" and its first revised document in 1992. 1 Scope and purpose 1.1 Scope This standard specifies the general safety requirements for electrical equipment for professional, industrial process and educational use, including equipment and computing devices for the following purposes: measurement and testing, control; laboratory use; accessories used with the above equipment and devices (such as sample handling equipment). This standard applies to equipment defined in a) to c) below and used in the environment specified in Article 1.4. a) Electrical measuring and test equipment refers to equipment that measures, indicates or records one or more electrical or non-electrical quantities by electrical methods, including non-measuring equipment such as signal generators, measuring standards, power supplies, transducers and transmitters. b) Electrical control equipment refers to equipment that controls one or more output quantities to specified values. Each specified value can be set manually, locally or remotely, or controlled by one or more input variables. c) Electrical laboratory equipment
Equipment for measuring, indicating, monitoring or analyzing substances or for preparing materials. This equipment can also be used outside the laboratory. 1.1.1 Contents not included in the scope of this standard This standard does not include: bZxz.net
Reliable function, performance or other characteristics of equipment; maintenance (repair);
-Protection of maintenance (repair) personnel,
Note: Maintenance personnel should be particularly careful when dealing with obvious dangers, but warning labels, shielding of dangerous voltage terminals and isolation of low voltage circuits from dangerous voltages should be used in the design to prevent accidents. More importantly, maintenance personnel should be trained to prevent accidental dangers. Approved by the State Technical Supervision Bureau on December 29, 1995 and implemented on October 1, 1996
1.1.2 Equipment not included in the scope of this standard This standard does not include:
Electrical equipment, such as power electronic equipment; GB4793. 1—1995
-Machine tools and machine tool control devices (see IEC204 "Electrical equipment for industrial organizations"); -0.5, 1 and 2 level AC Watt-hour meters (see IEC521 "0.5, 1 and 2 level AC Watt-hour meters") Medical electrical equipment within the scope of IEC601 "Medical Electrical Equipment"; Bio-amplifiers that connect equipment to the human body within the scope of research or education; Type tests and partial type test assemblies for low-voltage switchgear and controlgear (see IEC439-1 "Low-voltage switchgear and controlgear assemblies Part 1: Type tests and partial type test assemblies"; Circuits and equipment that form part of the electrical installations of buildings (see IEC364 "Electrical installations of buildings"; Computers, processors and Similar devices, except for the equipment specified in 1.1.3 (see IEC950 "Safety of Information Technology Equipment (including Electrical Business Equipment)");
Transformers separated from the equipment (see IEC742 "Requirements for Isolation Transformers and Safety Isolation Transformers"); household equipment (see IEC335 "Safety of Household and Similar Electrical Appliances"); - Equipment used in explosive atmospheres (see IEC79 "Electrical Equipment in Explosive Gases"). 1.1.3 Computing Equipment
This standard applies only to computers and processors that form part of the equipment within the scope of this standard or are designed to be used only with the equipment. Note: Computing devices and similar equipment within the scope of IEC950 and complying with its requirements can be considered suitable for connection with the equipment within the scope of this standard. 1.2 Purpose
The purpose of this standard is to ensure that the design of the equipment and the construction methods used provide adequate protection for the operator and the surrounding environment in the following aspects:
Electric shock or electrical burns (see Chapter 6);
Mechanical hazards (see Chapters 7 and 8); excessive temperature (see Chapter 9);
Flame, spreading from the inside of the equipment to the outside (see Chapter 9); radiation effects, including laser sources, sound pressure and ultrasonic pressure (see Chapter 12); gas release, explosion and burst (see Chapter 13). NOTE: Attention should be paid to additional requirements prescribed by the national authority responsible for the health and safety of workers. 1.3 Verification
This standard also specifies methods for verifying compliance with the requirements of this standard by inspection and type testing. NOTE: Recommended routine tests for production lines are given in Annex K. 1.4 Environmental conditions
This standard applies to equipment that can be used safely under at least the following environmental conditions: indoor use;
altitude below 2000m, or specified by the manufacturer to be above 2000m (see Chapter D9); temperature within the range of 5℃ ~ 40℃,
the maximum relative humidity is 80% when the temperature is below 31℃; the relative humidity decreases linearly to 50% when the temperature is 40℃; - the power supply voltage fluctuation should not exceed the nominal voltage ±10%; - other power supply voltage fluctuations should be in accordance with the manufacturer's regulations; transient overvoltage is facility category (overvoltage category) I, II and sub (see Appendix J), for the power supply, the minimum and normal category is Class I;
the pollution degree is Class 1 or Class 2, see IEC664 "Insulation coordination of low-voltage systems, including electrical clearances and creepage distances of equipment" in 392
3.7.3.
2 Standard references
GB 4793.1-1995
The provisions contained in the following standards constitute the provisions of the first part of this standard through reference in this standard. When this standard is published, the standard versions shown are valid. All standards will be revised, and the parties to the agreement based on this standard should explore the possibility of using the latest versions of the following standards. The member countries of IEC and ISO maintain the versions of the currently valid international standards. 2.1EC Standards
50(151):1978 International Electrotechnical Commission - Chapter 151: Electrical and Magnetic Devices 50(351):1975 International Electrotechnical Commission - Chapter 351: Automatic Control 51 Direct-Acting Analog Indicating Electrical Measuring Instruments and Accessories 60 High Voltage Test Technology
60-2:1973 High Voltage Test Technology Part 2: Test Procedure 65:1985 Safety Requirements for Household and Similar General Purpose Electronic and Related Equipment Powered by the Mains 68-2-3:1969 Environmental Testing - Part 2: Test Ca : Steady-state condensation 68-2-6: 1992 Environmental testing - Part 2: Test Fc and guidelines: Vibration (sinusoidal) 68-2-31: 1969 Environmental testing - Part 2: Test Ec: Fall and overturn, mainly used for equipment samples 85: 1984 Electrical insulation heat resistance evaluation and classification 227 Polyvinyl chloride insulated cables with rated voltages of 450/750V and below 245 Rubber insulated cables with rated voltages of 450/750V and below 309 Industrial plugs, sockets and connectors
Electrical and electronic test equipment performance Method of representation 359:1987#
417:1973 Graphic symbols for equipment (including indexes, lists and single-page information compilations) 529:1989 Degrees of protection provided by enclosures 617-2:1983 Graphic symbols Part 2: Symbol elements, limiting symbols and other commonly used symbols 664 Insulation coordination of equipment in low-voltage systems
Flexible cord assemblies
799:1984
Low-voltage switchgear and controlgear - Part 1 General rules 947-1:1988
947- 3:1990
Low-voltage switchgear and controlgear-Part 3: Switches, circuit breakers, switch-circuit breaker and fuse combination units
Methods of measuring contact and protective conductor currents 990:1990
707:1981
817:1984
Test methods for determining the flammability of solid electrical insulation when exposed to an ignition source Spring impact test apparatus and calibration thereof
Radiation, equipment classification, requirements and user guide for laser products 825:1984
2.2ISO Standards
306:1987 Plastics Thermoplastic materials, Determination of Vicat softening point and intensity 3864:1984 Safety colors and safety symbols 3 Definitions
This standard adopts the following definitions:
For other definitions adopted in this standard, see IEC50 (351), IEC51 and IEC359. Unless otherwise specified, the definitions of "voltage" and "current" refer to the effective value of AC, DC or composite voltage or current. 3.1 Equipment and equipment categories
3.1.1 Fixed equipmentfixequipment
Equipment fixed to a bracket or a specific location. GB4793.1—1995
3.1.2 Permanently connected equipmentpermanently connected equipmentEquipment that is electrically connected to the power supply by a permanent connection method, and this connection can only be disconnected by using a tool. 3.1.3 Portable equipmentportableequipmentEquipment intended to be carried by hand.
3.1.4 Hand-held equipment Portable equipment intended to be held in one hand only in normal use. 3.1.5 Tool
External device used to assist a person in performing a mechanical function, including keys and coins. 3.2 Parts and accessories
3.2.1 Terminal
Component used to connect a device (equipment) to an external conductor [IEV151-01-03]. Note: It can contain one or more terminal contacts. 3.2.2 Functional earth terminal A terminal device electrically connected directly to a point in a measuring circuit or control circuit or to a shield, which is grounded for functional purposes rather than for safety purposes.
Note: On measuring equipment, this terminal is often called the "measurement earth terminal". 3.2.3 Protective conductor terminal A terminal to which conductive parts of equipment are connected for safety purposes, and which will be connected to an external protective earthing system. 3.2.4 Enclosure
Prevents the equipment from certain external influences and direct contact with the internal parts of the equipment from any direction. 3.2.5 Barrier
Prevents direct contact with the parts from any normal approach direction. Note: Enclosures and baffles can prevent the spread of flames (see 9.1 and Appendix F). 3.3 Electricity
3.3.1 Rated (value)
Nominal value usually given by the manufacturer for the working conditions of components, devices or equipment [IEV151-04-03]. 3.3.2 Rated working conditions rating
A set of rated values ​​and working conditions [IEV151-04-04]. 3.4 Test
3.4.1 Type test
Type test
For a specific design, one or more equipment (or equipment parts) samples are used to prove that the design and structure of the equipment meet one or more requirements of this standard. NOTE This is an extension of the definition in IEV151-04-15 to include design and construction requirements. 3.4.2 Routine test A test performed on each piece of equipment during or after manufacture to determine whether it complies with a criterion (see Annex K) [IEV151-04-16].
3.5 Safety terms
3.5.1 Accessible (of a part) A component that can be touched by a standard test finger or test needle when applied as specified in 6.2. 3.5.2 Hazardous live
Capable of causing electric shock or burns under normal use conditions or under single fault conditions (see 6.3.1 for the value under normal conditions and 6.3.2 for the higher value under single fault conditions). 394
3.5.3 High integrity
GB 4793.1-1995
No damage is likely to cause a hazard within the meaning of this standard; high integrity components are considered not to be prone to failure in tests under fault conditions.
3.5.4 Protective impedanceprotective impedanceComponent, component assembly or assembly consisting of basic insulation and current (or voltage) limiting devices, whose impedance value, construction and reliability, when connected between hazardous live parts and accessible conductive parts, can provide the protection required by this standard under normal and fault conditions.
3.5.5 Protective bondingprotective bondingConnection connecting accessible conductive parts and (or) protective screens to the means for connecting external protective conductors to provide electrical continuity.
3.5.6 Normal usenormal use
Operation in accordance with the instructions for use or the obvious intended purpose, including standby. Note: In most cases, normal use also refers to normal conditions, because the operating instructions will warn the user not to use the equipment under abnormal conditions. 3.5.7 Normal condition Normal condition Condition in which all hazard protection measures are intact. 3.5.8 Single fault condition Condition in which a hazard protection measure fails or a fault exists that may cause a hazard. Note: If a single fault condition inevitably causes another single fault condition, the two failures are considered to be a single fault condition. 3.5.9 Operator Operator Any person who uses the equipment for its intended purpose. 3.6 Insulation 3.6.1 Basic insulation Basic insulation Insulation whose failure may cause electric shock. Note: Basic insulation may also be used for functional purposes. 3.6.2 Supplementary insulation Supplementary insulation Independent insulation applied in addition to basic insulation to ensure protection against electric shock in the event of a failure of the basic insulation. 3.6.3 Double insulation Double insulation Insulation consisting of basic insulation and supplementary insulation. 3.6.4 Reinforced insulation Reinforced insulation Insulation with protection against electric shock not less than double insulation, which may consist of several layers of insulation that cannot be tested separately like supplementary insulation or basic insulation.
3.7 Insulation coordination
3.7. Installation category (overvoltage category) Installation category (overvoltage category) The classification of installation systems or circuit components according to the nominal voltage to ground, using standardized transient overvoltage limit values. 3.7.2 Pollution pollution
Any foreign matter such as solid, liquid or gas (ionized gas) that will cause a decrease in dielectric strength or surface resistivity. 3.7.3 Pollution degree In order to evaluate electrical clearances, this standard uses two pollution degrees in the following microenvironments. 3.7.3.1 Pollution degree 1 No pollution or only dry non-conductive pollution, which has no adverse effects. 3.7.3.2 Pollution degree 2 Usually only non-conductive pollution, but occasionally it will be short-term conductive due to condensation. 3.7.4 Clearance
The shortest distance between two conductive parts in the air. 3.7.5 Creepage distance GB 4793. 1 - 1995
The shortest distance between two conductive parts along the surface of insulating material LIEV151~03-377. 3.8 Power supply mains
Definition in this standard "Power supply refers to the power supply that the user can obtain from the power distribution system or the power supply system on which the relevant equipment is designed (as described in Article 6.3.2.1 of the master).
4 Test
4.1 Overview
All tests in this standard are type tests performed on samples of equipment or equipment parts. The sole purpose is to check the design and structure of the equipment to ensure that it complies with the requirements of this standard. Equipment parts or components that meet the relevant standard requirements specified in this standard and are used in accordance with these requirements do not need to be tested repeatedly during the type test of the whole machine.
All tests should be carried out to determine that the equipment complies with the requirements of this standard, but if it can be determined after checking the equipment that the equipment can definitely pass the test, then this test can be omitted. The test is carried out under the following conditions: - Reference test conditions (see Clause 43)
- Fault conditions (see Clause 4.4).
1 If the rated range of environmental conditions of the equipment exceeds the range specified in Clauses 1 and 4, the manufacturer shall ensure that the equipment still meets the requirements of this standard (for example, by appropriately changing the test requirements or additional tests to ensure this). 2 If, when performing qualification tests, there is uncertainty in the applied or measured values ​​(e.g. voltage) due to tolerances, then: - the manufacturer shall ensure that the applied values ​​are at least the specified test values; the testing department shall ensure that the applied values ​​are not greater than the specified test values. 3 Equipment that has been type tested may no longer be suitable for its intended function due to the residual influence of certain test stresses, so equipment that has been widely distributed should not be type tested (e.g. by the user). 4.2 Test sequence
Unless otherwise specified in this standard, the test sequence is optional. The equipment under test shall be carefully checked after each test. If there is any doubt about the results of previous tests that have been passed and the test sequence has been reversed, the previous tests shall be repeated. If tests under fault conditions will damage the equipment, these tests may be placed after tests under reference test conditions. 4.3 Benchmark test conditions
4.3.1 Environmental conditions
Unless otherwise specified in this standard, the environmental conditions of the test site shall comply with the following provisions (but shall not conflict with the provisions of Article 1.4): Temperature: 15℃~35℃
Relative humidity: not more than 75%
-Atmospheric pressure: 75kPa-106kPa
-No frost, condensation, water seepage, rain and sunshine, etc. 4.3.2 Equipment status
Unless otherwise specified in this standard, the test shall be carried out on the assembled equipment for normal use and under the most unfavorable combination of conditions specified in Articles 4.3.3-4.3.16.
When a test cannot be carried out on the entire equipment due to volume or weight reasons, if the inspection proves that the assembled equipment can comply with this standard, the unit test is allowed.
4.3.3 Equipment location
The equipment is in any position for normal use, and normal ventilation is not blocked. 4.3.4 Accessories
GB 4793.1—1995
Accessories and operator-replaceable parts recommended or provided by the manufacturer for use with the test equipment may or may not be connected to the equipment under test.
4.3.5 Covers and removable parts
Cover or parts that can be removed without tools may or may not be removed. If a cover that can be removed without tools is equipped with an interlocking system that meets the requirements of 15, it does not need to be removed. 4.3.6 The power supply
shall meet the following requirements:
The supply voltage shall be between 90% and 110% of any rated supply voltage that the equipment can be set to, and within any fluctuation range if the equipment is marked with a larger fluctuation; the frequency shall be the rated frequency,
--AC and DC dual-purpose equipment shall be connected to an AC or DC power supply;--DC or single-phase power supply equipment shall be connected in normal connection and reverse polarity respectively;--Unless the equipment is specified to be used only for ungrounded power supply, one pole of the reference test power supply shall be at or close to ground potential;--Battery-powered equipment, if its connection method allows reversal, shall be connected in normal and reverse polarity. 4.3.7 Input and output voltages
The input and output voltages, including the shift voltage but not the supply voltage, shall be set to any voltage within the rated voltage range. 4.3.8 Grounding terminal
If there is a protective conductor terminal, it shall be connected to the earth. The functional grounding terminal may be grounded or ungrounded. 4.3.9 Control keys
Control keys that can be adjusted manually by the operator shall be set in any position, except for the following: the power selector is at the correct value,
--the manufacturer has marked on the equipment that the setting combination is prohibited. 4.3.10 Connections
The equipment is connected for its intended purpose or connected without any use. 4.3.11 Motor load
The load conditions of the motor-driven parts of the equipment shall be in accordance with the intended purpose. 4.3.12 Output
For equipment with electrical output:
-The equipment shall operate under the condition of providing rated output power to the rated load;--the rated load impedance of any output is connected or not connected. 4.3.13 Working cycle
Equipment for short-term or intermittent operation shall operate for the longest cycle and the shortest recovery period in accordance with the manufacturer's operating instructions. 4.3.14 Loading and filling
Equipment intended to be loaded with a specified material shall be loaded (filled) with the maximum amount of the specified material or shall be unloaded (unloaded). NOTE: If the specified material may cause a hazard during the test and the use of another material will not affect the test results, an alternative material may be used. 4.3.15 Heating equipment
When the temperature of heating equipment is measured to assess its flame spread, the test shall be carried out in the test corner in accordance with 9.2.1. 4.3.16 Built-in equipment
Equipment intended to be installed in an enclosure or on a wall shall be installed in accordance with 9.2.2 when its temperature is measured to assess its flame spread.
4.4 Tests under single fault conditions
4.4.1 Overview
The following requirements shall be followed:
GB 4793.1-1995
-Generally, check the equipment and its circuit diagram to determine the fault conditions that may cause danger within the meaning of this standard, and apply them;-Unless it has been proved that a specific fault will not cause danger, the fault test shall be carried out; The equipment shall work under the most unfavorable combination of reference test conditions (see 4.3), and the combination is different for different faults. The combination shall be recorded in each test
Appendix F gives an alternative test for the test of preventing the spread of flame under fault conditions (9.1). 4.4.2 Application of fault conditions
The fault conditions shall include those specified in 4.4.2.1 to 4.4.2.12, and shall be applied one at a time in the most convenient order. Multiple faults shall not be applied at the same time unless it is the result of applying a fault. After each fault is applied, the equipment or component shall be able to pass the test of 4.4.4. 4.4.2.1 The protective impedance
shall be as follows:
If the protective impedance consists of components, each component shall be short-circuited or open-circuited, whichever is more unfavorable. If it is composed of basic insulation and current or voltage limiting devices, both shall be subjected to single fault conditions, one fault condition being applied at a time. The basic insulation shall be short-circuited and the current or voltage limiting devices shall be short-circuited or open-circuited, whichever is more unfavorable.
High integrity components in the protective impedance need not be short-circuited or open-circuited (see 4.5.3 and 14.6). 4.4.2.2 Protective conductor
The protective conductor shall be disconnected, except for permanently connected equipment or equipment using connectors specified in IEC 309 "Plugs, sockets and connectors for industrial use".
4.4.2.3 Equipment or parts operating for short periods or intermittently If a single fault condition could cause the equipment or parts to operate continuously, they shall be operated continuously. Parts include motors, relays, other electromagnetic devices and heaters.
4.4.2.4 Motors
The motor shall be stopped when fully energized or prevented from starting, whichever is the more unfavorable. 4.4.2.5 Capacitors
Capacitors (except self-healing capacitors) in the circuit of auxiliary windings of motors shall be short-circuited. 4.4.2.6 Power transformers
The secondary windings of power transformers tested as part of the equipment shall be short-circuited and subjected to the overload caused by any of the fault conditions in 4.4.
The windings and parts of the tapped windings which are normally loaded shall be simulated with a short-circuit of the load, only one at a time. All other windings shall be loaded or unloaded, whichever is the more unfavorable of the normal use loads. If a current limiting impedance or overcurrent protection device is directly connected in the circuit of the winding, it shall be short-circuited on the load side. The requirements and tests for power transformers tested as discrete components are specified in 14.7. 4.4.2.7 Output
The outputs of the equipment shall be short-circuited one at a time. 4.4.2.8 Equipment powered by more than one type of power supply Equipment designed to be powered by more than one type of power supply shall be connected to those power supplies simultaneously unless it is structurally prevented from doing so. 4.4.2.9 Cooling
Cooling of the equipment shall be limited as follows, applied one at a time: Closing of the filter vents;
- Stopping forced cooling by motor-driven fans; - Stopping cooling by circulating water or other coolants. 4.4.2.10 Heating devices
GB 4793.11995
Equipment containing heating devices shall be subjected to the following faults, applied one at a time: - The timer limiting the heating time shall be cancelled so that the heating circuit operates continuously - The temperature controller (except for over-temperature protectors that meet the requirements of 14.3) shall be cancelled so that the heating circuit operates continuously; - Simulated loss of coolant.
4.4.2.11 Insulation between circuits and parts The insulation between circuits and parts listed in Appendix G shall be short-circuited unless the inspection of 9.1 has been passed. 4.4.2.12 Interlocks
If, after removal of a cover, etc. that does not require the use of a tool, the operator is protected from hazardous contact by an interlock system (see 1.2), each component of the system shall be short-circuited or open-circuited in turn. High integrity components of the interlock system (see 14.6 and 15.3) do not need to be short-circuited or open-circuited. 4.4.3 Duration of test
4.4.3.1 The equipment shall continue to operate until the failure result cannot be changed further. Each test is generally limited to 1 hour, because the failure caused by the abnormal conditions simulated can usually show its effect within 1 hour. If at the end of 1 hour, the equipment shows signs of electric shock, flame spread or personal injury, the test shall be continued until the final result is obtained or the test is 4 hours.
4.4.3.2 For equipment that uses a device that interrupts or limits the temperature of accessible parts, the maximum temperature that the equipment can reach shall be measured regardless of whether the device operates or not. 4.4.3.3 If the fault is terminated by the operation of a fuse and the fuse does not operate within approximately 1 s, the current flowing through the fuse under the relevant fault conditions shall be measured. The pre-arcing time/current characteristics shall be evaluated to determine whether the minimum operating current of the fuse and the maximum time before the fuse operates have been reached or exceeded. It should also be noted that the current through the fuse will vary with time. If the minimum operating current of the fuse is not reached during the test, the operating time of the equipment under test shall correspond to the maximum fusing time or the continuous operating time specified in Clause 4.4.3.1. 4.4.4 Compliance
4.4.4.1 Compliance with the requirements for protection against electric shock is checked by the following: the measurements of 6.3.2;
For places where double insulation or reinforced insulation is used, the voltage test is carried out in accordance with 6.8.4, but the test voltage is applied only as for basic insulation.
Note: The basic insulation test simulates a single fault condition of failure of one layer of double insulation or failure of part of reinforced insulation. 4.4.4.2 Compliance with the temperature requirements is checked by measuring the temperature of external surfaces or accessible parts. Except for the heated surfaces of heating equipment, the temperature of these parts shall not exceed 105°C when the ambient temperature is 40°C (see 1.4). The temperature is determined by measuring the temperature rise of the surface or part plus 40°C. 4.4.4.3 In order to determine whether the precautions against the spread of fire are satisfactory, the equipment under test, covered with gauze, shall be placed on a cork board covered with tissue paper. During the test, no molten metal, burning insulation, flaming particles, etc. shall fall onto the surface on which the equipment under test is placed, and tissue and gauze shall not carbonize, burn or catch fire. Melting of insulating materials that are not important according to the requirements of this standard shall be ignored. 4.4.4.4 Compliance with the requirements for protection against other hazards mentioned in Clause 1.2 shall be checked in accordance with Clauses 7 to 15. 5 Marking and Documentation
5.1 Marking
5.1.1 General
The equipment shall be marked in accordance with Clauses 5.1.2 to 5.2 and these markings shall be visible from the outside or after removal of covers or doors that can be opened by the operator without tools. The marking of the entire equipment shall not be marked on parts that can be removed by the operator without tools. The marking of frame-mounted or panel-mounted equipment may be marked on any surface that is visible after the equipment is removed from the frame or panel. 399
GB4793.1—1995
The text symbols of the value and unit shall comply with IEC27 "Text Symbols for Electrical Technology", and the graphic symbols shall comply with Table 1. Note: Except for handheld equipment or equipment with limited surface area, the marking should not be marked on the bottom of the equipment. Use visual inspection.
5.1.2 Identification
The equipment shall at least be marked with:
Manufacturer name or registered trademark;
-Model, name or other method used to identify the equipment. Use visual inspection.
Table 1 Graphical symbols for equipment
Background—yellow
Symbols and borders
Black 1)
Background—yellow
Symbols and borders
Black)
Publication
IEC 417
No. 5031
IEC417
No. 5032
IEC417
No. 5033
IEC617-2
No. 02-02-06
IEC 4175017
IEC 417 | No. 5172
ISO3864, B.3.6
ISO3864, B.3.6
AC and DC
Three-phase AC
Earth terminal
Protective conductor terminal
Frame or chassis terminal
Equipotential
On (power supply)
Off (power supply)
Equipment protected by double insulation or reinforced insulation (equivalent to Class 1 equipment of IEC536, see Appendix H)
Caution risk of electric shock
Accessible parts with high temperature
Note (refer to accompanying documents)
1) If the symbol is molded or etched on the equipment 0.5 mm high or deep, the color of symbol 12 and symbol 14 may not be used. The symbol should be large enough to be noticed when necessary.
5.1.3 Power supply
The equipment shall be marked with the following information:
a) Nature of power supply:
GB 4793.11995
-AC: rated power supply frequency or frequency range; DC: use symbol 1 in Table 1.
Note: The facility category (overvoltage category) of the equipment shall be given in the document, which is related to the transient overvoltage resistance. The following information may also be marked: AC equipment: symbol 2 in Table 1;
AC and DC dual-purpose equipment: symbol 3 in Table 1; three-phase power supply equipment: symbol 4 in Table 1. b) Rated value or rated voltage range of supply voltage Note: The range of allowed rated voltage fluctuation may also be marked. c) Maximum rated power (in W for active power or in VA for apparent power) or maximum rated input current when all accessories or plug-in units are attached.
d) Equipment that can be set to different rated supply voltages by the operator shall provide an indication of the set voltage. For portable equipment, this indication shall be visible from the outside. If the equipment is designed to allow the operator to change the supply voltage setting without tools, the voltage indication shall change simultaneously with the voltage setting. e) Auxiliary power sockets on equipment that can accept standard power plugs shall be marked with the voltage value if the voltage is different from the supply voltage. If the socket is only for special equipment, it shall be marked to indicate the equipment intended for use with it. If there is no such marking, the maximum rated current or power and the maximum permissible leakage current shall be marked, or symbol 14 in Table 1 shall be marked next to the socket and all information shall be included in the documentation.
The marking of items 5.1.3 shall be checked by visual inspection and by measuring the power or input current. The measurements shall be made under the reference test conditions (see 4.3), but the equipment is connected to the rated supply voltage. The measured value shall not exceed the marked value by more than 10%. 5.1.4 Fuses
Any fuse that can be replaced by the operator should be marked with the current rating and model next to its seat, such as an indication of its fusing speed (such as using the IEC127 symbol, see the symbols given below). For fuses that cannot be replaced by the operator, similar information should be provided in the document (see 5.4.5).
Note: The text and color symbols of IEC127 are as follows: - Fast response. FF or black:
- Fast response F or red;
- Medium delay: M or yellow 1
- Delay: T or blue:
- Long delay. TT or gray.
Use visual inspection,
5.1.5 Measurement circuit terminals
Unless the measuring equipment clearly indicates that the equipment will not be connected to a voltage greater than 50V (ac) or 120V (dc) to ground, the input circuit connected by the operator for voltage or current measurement should be marked with the maximum rated voltage to ground. However, circuit terminals (connectors) that have been specified to be connected only to other devices and have methods to identify these "specific terminals" may be exceptions. Examples of suitable indications that the input will be lower than 50V (ac) or 120V (dc) (to ground) in any case include: the full-scale deflection mark of a single-range indicating voltmeter or the maximum mark of a multi-range voltmeter; the maximum range mark of a voltage selector switch; the instrument's predetermined function mark (such as "millivoltmeter"). The mark should be marked near the terminal, but if there is not enough space (such as multi-input equipment), it can also be marked on the nameplate or dial, or the symbol 14 in Table 1 can be marked on the terminal.
Use visual inspection.
5.1.6 Terminals and operating devices
GB 4793. 1-1995
Where safety is concerned, terminals, connectors, controls and indicators shall be marked with words or symbols indicating their purpose, including the order of operation. If space is insufficient, symbol 14 in Table 1 may be used. Note: For additional information, see IEC445 "General rules for identification of equipment terminals and terminations of a particular conductor, including an alphanumeric system" and IEC447 "Standard direction of movement of actuators that control the operation of electrical equipment". The following terminals and operating devices shall be marked as specified: a) Functional earthing terminals shall be marked with symbol 5 in Table 1. b) Protective conductor terminals shall be marked with symbol 6 in Table 1, unless the protective conductor terminal The terminal is part of an approved power connector. This symbol should be close to the terminal or on the terminal.
c) For control circuit and measuring circuit terminals connected to accessible conductive parts in accordance with 6.6.3, where their connection is not obvious, use symbol 7 from Table 1.
Note: This symbol can also be used as a warning symbol to indicate that hazardous voltage should not be connected to this terminal. This symbol should be used where the operator may make such a connection without noticing.
d) Terminals that are powered by electricity from within the equipment and are hazardous live should be marked with voltage, current, charge or energy values ​​or ranges, or marked with symbol 14 from Table 1. This clause applies to the use of standards Power sockets for power sockets are not applicable. e) For accessible functional earth terminals connected to accessible conductive parts, such connection shall be indicated unless it is obvious (see 5.6.2.2). Symbol 8 of Table 1 may be used as such marking. f) If there is a power switch or circuit breaker, its "on" or "off" position, or both, shall be clearly marked and suitable for identification of the device, see 6.12.3.1. Indicator lights cannot be considered as satisfactory marking. NOTE: Symbols 9 and 10 of Table 1 may be used for this purpose, but cannot be used to mark other switches, by self-visual inspection.
5.1.7 Protection by double insulation or reinforced insulation Equipment that is entirely protected by double insulation or reinforced insulation (see Annex H) shall be marked with symbol 11 of Table 1, except for equipment provided with a protective conductor terminal.
Equipment that is only partially protected by double insulation or reinforced insulation shall not be marked with this symbol. Visual inspection.
5.1.8 Battery charging
Equipment that has provisions for charging rechargeable batteries and in which non-rechargeable batteries can be loaded and connected in a battery compartment shall be marked on or near the battery compartment to prevent the charging of non-rechargeable batteries and to indicate the type of rechargeable battery used with the rechargeable circuit. Note: Symbol 14 of Table 1 is acceptable.
Visual inspection.
5.2 Warning markings
Equipment delivered for use shall have warning markings that are clearly visible. If the user needs to consult the instructions to know the protection provided by the equipment, the equipment shall be marked with symbol 14 of Table 1. If the warning applies to a specific part of the equipment, the mark shall be on or near that specific part. The warning should advise the operator to avoid contact with "hazardous live" parts that are classified as accessible according to 6.1.1. Terminals with a voltage of more than 1 kV provided by the machine or allowed to be connected to a voltage of more than 1 kV (see 6.6.2) should be marked with symbol 12 in Table 1.
Unless the heating state of the parts is obvious or can be seen from the function of the equipment, easily accessible parts that exceed the temperature limits of Table 3 allowed by 9.1 should be marked with symbol 13 in Table 1. If the danger (see 1.2) will continue for more than 2 seconds after the interlock system (see 15.1) is activated, the operator should be warned. NOTE
1 The safety warning should have a large contrast with the background color. 4028 Battery Charging
Equipment that has means for charging rechargeable batteries and that can be loaded and connected to a battery compartment with non-rechargeable batteries shall be marked on or near the compartment to prevent the charging of non-rechargeable batteries and to indicate the type of rechargeable battery to be used with the rechargeable circuit. Note: Symbol 14 in Table 1 is acceptable.
Inspect by visual inspection.
5.2 Warning Marking
Equipment delivered for use shall have warning markings that are clearly visible. If the user needs to consult the instructions to know the protection provided by the equipment, the equipment shall be marked with symbol 14 in Table 1. If the warning applies to a specific part of the equipment, the mark shall be marked on or near that specific part. The warning shall advise the operator to avoid contact with "hazardous live" parts that are classified as accessible in accordance with 6.1.1. Terminals that are provided with a voltage of more than 1 kV or are allowed to be connected to a voltage of more than 1 kV (see 6.6.2) shall be marked with symbol 12 in Table 1.
Unless the heated state of the part is obvious or can be seen from the function of the equipment, easily accessible parts that exceed the temperature limits of Table 3 as permitted by 9.1 shall be marked with symbol 13 of Table 1. If the hazard (see 1.2) will continue for more than 2 s after the interlock system (see 15.1) is actuated, the operator shall be warned. NOTE
1 The safety warning shall have a high contrast with the background color. 4028 Battery Charging
Equipment that has means for charging rechargeable batteries and that can be loaded and connected to a battery compartment with non-rechargeable batteries shall be marked on or near the compartment to prevent the charging of non-rechargeable batteries and to indicate the type of rechargeable battery to be used with the rechargeable circuit. Note: Symbol 14 in Table 1 is acceptable.
Inspect by visual inspection.
5.2 Warning Marking
Equipment delivered for use shall have warning markings that are clearly visible. If the user needs to consult the instructions to know the protection provided by the equipment, the equipment shall be marked with symbol 14 in Table 1. If the warning applies to a specific part of the equipment, the mark shall be marked on or near that specific part. The warning shall advise the operator to avoid contact with "hazardous live" parts that are classified as accessible in accordance with 6.1.1. Terminals that are provided with a voltage of more than 1 kV or are allowed to be connected to a voltage of more than 1 kV (see 6.6.2) shall be marked with symbol 12 in Table 1.
Unless the heated state of the part is obvious or can be seen from the function of the equipment, easily accessible parts that exceed the temperature limits of Table 3 as permitted by 9.1 shall be marked with symbol 13 of Table 1. If the hazard (see 1.2) will continue for more than 2 s after the interlock system (see 15.1) is actuated, the operator shall be warned. NOTE
1 The safety warning shall have a high contrast with the background color. 402
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