GB 16836-1997 General requirements for safety design of measuring relays and protective devices
Some standard content:
GB16836-1997
Foreword
In order to adapt to international trade, technology and economic exchanges and ensure the safety of use of measuring relays and protective devices, this standard is specially formulated. In view of the fact that there are no special safety standards in the IEC255 "Electrical Relays" series of standards, the safety requirements for electrical relays are mainly in Appendix A "Determination of Electrical Relays Part 5: Insulation Test of Electrical Relays" of IEC255-5 (first edition in 1977) Partial provisions are made in "Guidelines for Dielectric Test Voltage Values", Appendix B "Guidelines for Determining Electrical Trace and Creepage Distances", Appendix E "Opinions on Relevant Safety Measures", or by citing other standards. Due to the changes in IEC standard versions and the mutual reference of these standards, it is insufficient or inconvenient to only use IEC255-5 and its referenced standards as the safety requirements for electrical relays. It is now necessary to draft this standard. Most of the above-mentioned international standards have been adopted as equivalent or equivalent to national standards. This standard refers to these standards or quotes these standards in order to be consistent with these standards.
Appendix A of this standard is the standard appendix; Appendix B is the reminder appendix. This standard is proposed and centralized by the National Technical Committee for Standardization of Measuring Relays and Protection Equipment. This standard was drafted by: Xuchang Relay Research Institute, Acheng Relay Factory. Drafters of this standard: Tian and Zhou Shixian. | |tt |
This standard specifies the general requirements for the safety design of measuring relays and protective devices and their inspection methods. This standard applies to newly developed and designed measuring relays and protective devices, as well as complete sets of protective equipment composed of them (hereinafter referred to as product).
This standard does not apply to products under special environmental conditions. 2 Referenced standards
The provisions contained in the following standards constitute provisions of this standard by being quoted in this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties using this standard should explore the possibility of using the latest version of the standard listed below. GB2682-81
Color of indicator lights and buttons in electrical equipment GB4205-84 Standard direction of movement of operating parts for controlling electrical equipment 3 Housing protection level (IP code)
GB4208—93||tt ||GB 4776—84
Electrical safety terms
GB4793-84 Safety requirements for electronic measuring instruments GB5169.5-85 Fire hazard test for electrical and electronic products Needle flame test method
GB7261- 87 Basic test methods for relays and relay protection devices Color marking of insulated conductors and bare conductors
GB7947—87
GB11021—89
Thermal resistance evaluation and classification of electrical insulation|| tt | Protection against electric shock of electrical installations in buildings
Under the conditions that the product is manufactured in accordance with the product design requirements and used and maintained in accordance with the requirements of the product manual, the product should achieve the following safety objectives during manufacturing, use and maintenance: a ) The product can resist external non-mechanical influences under expected environmental conditions without endangering people, livestock and property; b) The product can meet the expected mechanical requirements without endangering people, households and property; c) The product can People, livestock and property should not be endangered under foreseeable overload conditions; d) The product should have adequate protection against physical injuries and other hazards caused by direct or indirect electric contact of people and livestock; e) The product should not produce hazards that endanger people and livestock. Temperature, arc or radiation of livestock; State Bureau of Technical Supervision approved on 1997-06-03 for implementation on 1998-05-01
GB16836-1997
f) The insulation of the product should be suitable for foreseeable conditions; g) Products should have adequate protection against other dangers that endanger people and property. Direct safety technical measures should be adopted as much as possible in product design. When it is impossible or not completely possible, indirect safety technical measures and suggestive safety technical measures should be adopted.
4 Definitions
The safety-related terms used in this standard adopt the definitions of GB4776. 5 Requirements
5.1 Mechanical structure
5.1.1 The materials selected for the product structure should be able to withstand the mechanical, physical and chemical effects that may occur under the conditions of use, and must not cause harm to people. 5.1.2 The appearance of the product should avoid sharp corners, edges, burrs and rough surfaces to avoid harm to the human body. 5.1.3 The design of the product’s transmission, rotation, swing and other moving parts should avoid danger caused by human contact, otherwise safety technical measures should be taken.
5.1.4 The movement direction of the operating mechanism of the control part of the product should comply with the provisions of the GB4205 standard. 5.1.5 Products should have reliable stability design and firm connection and installation to avoid injury to people due to toppling or falling off due to vibration, impact, and collision. When necessary, safety issues such as the strength and stability of the product during transportation should also be considered. 5.2 Enclosure protection
5.2.1 The protection provided by the enclosure prevents access to hazardous mechanical and live parts, the intrusion of solid foreign objects and the ingress of water into the interior.
5.2.2 The code for the protection provided by the enclosure is: 000
IP
Supplementary letters (letters H, M, S, W, optional) additional letters (letter A , B, C, D, optional) the second characteristic number (0~8, or X)
the first characteristic number (0~6, or ) The meanings of each letter and number code are shown in Table 1. Composition
The first characteristic number
The second characteristic number
Additional letters
(optional)
Supplementary letters
( Optional)
Numbers or letters
o
1
2
3
5
6||tt ||x
0
1
2
3
4
5
6
7
8
x
A
B
C
D
H
M| |tt||s
W
GB16836—1997
Composition and meaning of Table 1 IP code
The meaning of protective equipment
Prevent the entry of solid foreign matter| |tt||No protection
Diameter ≥50mm
Diameter ≥12.5mm
Diameter ≥2.5mm
Diameter ≥.0mm
Dust-proof|| tt||Dust tight
No requirement for protection
Prevent water from entering
No protection
Vertical dripping
15° dripping
Spraying water
Splashing water
Spraying water
Violent spraying of water
Short-time immersion
Continuous immersion
No requirement||tt| |Specially supplemented content
High voltage equipment
The sample is running during the waterproof test
The sample is stationary during the waterproof test
Climate conditions
Protector Meaning
Prevent people from approaching dangerous parts
No protection
Back of hand
Fingers
Tools
Metal wire
Metal Wire
Metal wire
No protection required
Prevent access to dangerous parts
Back of hand
Fingers
Tools
Metal Line
3 is provided with human protection by the shell, and its degree of protection can be selected according to Table 1. If there are further requirements, please refer to GB4208. 5.2.3
5.2.4 The mark of the enclosure protection level should be marked on the nameplate or enclosure of the product, or specified in the instructions. 5.3 Insulation coordination
5.3.1Insulation coordination refers to the interrelationship of the insulation properties of the product taking into account the expected micro-environment and other influencing factors. If the design of the product takes into account these influencing factors during its life, the purpose of insulation coordination can be well achieved. 5.3.2 The main factors affecting product insulation coordination are: a) voltage level;
b) overvoltage category;
c) electric field conditions (uniform electric field or non-uniform electric field): d) pollution level ;
e) Comparative tracking index (CTI) that reflects material properties; f) Altitude (atmospheric pressure).
5.3.3 The insulation coordination design of the product should consider both the electrical clearance and the creepage distance, and the creepage distance shall not be less than the electrical clearance.
5.3.4 The minimum values ??of electrical clearance and creepage distance should be selected according to the provisions of GB/T14598.3. 5.3.5 When the altitude exceeds 2000m, the correction value of the electrical clearance is shown in Table 2. Table 2 Altitude correction value of electrical clearance
Altitude height
m
2000
3000
4.000
5000||tt ||Standard atmospheric pressure
kPa
80.00
70.00
62.00bzxz.net
54.00
5.3.6 After the electrical clearance is determined, the product is still It should be able to withstand the impulse voltage test specified in the standard. 5.4 Heating requirements
5.4.1 The product should not have the following phenomena under normal operation and foreseeable failure conditions: a) Temperature that causes combustion of parts;
b) Human body and accessible parts Risk of burns when parts come into contact: c) Deformation of the housing.
5.4.2 Allowable temperature rise
Clearance correction coefficient
1.00
1:14
1.29
1.48||tt| |Under normal working conditions, after the product reaches a thermal equilibrium state, use the method of measuring temperature to check the allowable temperature rise, which shall not exceed the value given in Table 3.
Table 3 Allowable temperature rise
Part
Outer surface of the shell
External
Inside the shell
Surface
Power transformer
bit
metal knobs, handles and other operating parts
non-metal knobs, handles and other operating parts
wooden
insulation material
insulation Use thermoplastic materials
Other parts
Allowance
Temperature rise
Normal working conditions
35
20
30
70
1)
2)
3)
1)
1) Shell made of insulating material, which The allowable temperature rise of the inner surface is determined by the corresponding material. 2) For a given material, its temperature rise is limited by the numerical value specified in GB11021, and the fault condition is
65
65
65
90
1 )
K
3) For different thermoplastic materials, it is impossible to specify the allowable temperature rise. It is recommended to use the Vicat test method to determine the softening temperature (that is, the temperature when the penetration depth is 0.1mm ).
The allowable temperature rise under normal operating conditions is 10K lower than the softening temperature, and it can be equal to the softening temperature under fault conditions. See 6.4.2 for Vikart test.
5.4.3 Maintenance of insulation
GB168361997
When the product is allowed to operate with temperature rise, the electrical clearance, creepage distance and insulation resistance shall not be lower than the values ??specified in the product standard. 5.4.4 Mechanical strength at high temperatures
When the product is working under the allowed temperature rise, it should have sufficient mechanical strength. If in doubt, the test can be carried out according to 6.4.4. 5.5 Fire hazard protection
5.5.1 Under internal fault conditions, or under overheating conditions caused by overload caused by external faults, there is a fire risk due to the following reasons:
a) Spontaneous combustion of components :
b) Overheating of the component ignites components and parts in contact with or adjacent to it; c) Component explosion and dripping hot particles ignite other components or components d) When the flammable gas emitted by the component reaches a certain concentration Spontaneous combustion or ignition; e) Ignition caused by flashover, arcing, and leakage tracking, 5.5.2 Products should adopt effective fire hazard protection designs to avoid the occurrence of fire hazards. 5.5.3 The following methods can effectively achieve the purpose of fire hazard protection: a) Correct selection of materials, such as metal materials or flame-retardant engineering plastics; b) Correct selection of components, with a certain margin in their rated power; c) Heat generation There should be sufficient heat dissipation distance between components and between heating components and flammable parts, or ventilation and heat dissipation design should be adopted; d) Avoid sparks or arcing due to poor electrical contact; e) Adopt designs to control fire propagation and flame spread. 5.5.4 Parts made of non-metallic materials in the product should be able to withstand the fire hazard test specified in this standard, with a severity level of 20s. 5.6 Protection against the risk of electric shock
5.6.1 Products should have measures to prevent direct electric contact and indirect electric contact. These measures can be taken separately or in combination. Protection against direct electric contact refers to protection against direct contact with live parts; protection against indirect electric contact refers to protection against contact with exposed conductive parts and external conductive parts that become live under fault conditions. 5.6.2 The electric shock protection function of the product can be completed by separate measures, or it can be completed by two or more protective functions. 5.6.2.1 Measures to independently complete the function of preventing direct electric shock include: a) using insulation protection (paint coatings, anode films, wood, unimpregnated paper, etc. cannot be regarded as insulating materials); b) using protection levels of at least IPXXB enclosure or barrier; c) Use barriers;
d) Place live parts outside the reach of the arm. 5.6.2.2 Measures to independently complete the function of preventing indirect electric contact include: a) automatically cutting off the power supply;
b) using Class I equipment or equivalent insulation protection; c) using electrical isolation circuits; ||tt ||d) Ungrounded local equipotential bonding: Connect all exposed conductive parts and external conductive parts of the product that can be touched at the same time with equipotential bonding wires to form an ungrounded local equipotential bonding environment. 5.6.2.3 Measures that have both the functions of preventing direct electric contact and preventing indirect electric contact include: a) Safety Extra Low Voltage (SELV);
b) Functional Extra Low Voltage (FELV).
For the specific requirements of 5.6.2.1～5.6.2.3 of this standard, please refer to GB14821.1. 5.6.3 Product operating shafts, knobs and handles made of non-insulating parts, setting and pre-adjusting parts, and voltage adjusting parts The manual parts, etc., must not be electrified to avoid the risk of electric shock.
5.6.4 Neither the protective ground terminal nor the measurement ground terminal should be charged. The terminals that receive charge from the internal capacitor should not be charged 10 seconds after the power is cut off, otherwise they should be protected or marked with safety marks. GB16836—1997
5.6.5 Terminals connected to internal live parts shall not be accessible. If they need to be accessed for operational reasons, the external terminals and sockets of the operation and measurement circuits should be concealed, covered, and reasonably arranged to avoid inadvertent access. When these measures are not possible, appropriate marking should be made.
5.6.6 Circuits that are conductively connected to the power grid (see 2.6.4 in GB4793-84) and equivalent circuits have the following mechanical structure requirements:
a) should be able to prevent The insulation between the circuit conductive connection to the grid power supply or the components on the circuit equivalent to this, and the accessible conductive parts is short-circuited due to accidental loosening of screws, wires, etc.; b) The strength of the wire connection points subjected to mechanical stress should not only Rely on tin soldering (this requirement does not apply to printed circuit board component leads); c) The electrical clearance and creepage distance between live parts and accessible conductive parts should comply with the provisions of 5.3. 5.6.71 Category safety products
5.6.7.1
The definition and requirements of Category I safety products are shown in GB/T12501. 5.6.7.2
Category I safety products should be guaranteed to be safe under fault conditions , the accessible conductive parts that easily become electrified are reliably connected to the protective grounding terminal or protective conductor, and can also be reliably connected to the protective shield, and their resistance value should not be greater than 0.5α. 5.6.81 Class I safety products
5.6.8.1
For the definition and requirements of Class I safety products, see GB/T12501. [Class 1 safety products should not have protective grounding terminals or protective conductors, and should be marked with the Class 1 product identifier 5.6.8.2
on the casing or nameplate (see Table 5).
5.6.9 Class II safety products
5.6.9.For the definition and requirements of Class 1 safety products, see GB/T12501. 5.6.9.2 Class II safety products should not have protective grounding terminals or protective conductors. 5.6.10 The product manual should indicate which of the safety categories of 5.6.7~5.6.9 the product belongs to. 5.6.11 The product’s dielectric strength test, insulation resistance test under humid conditions and impulse voltage test should comply with the requirements specified in GB/T14598.3.
5.6.12 Leakage current of product
When 1.1 times the rated voltage is applied to the product, the leakage current between each live circuit and all accessible conductive parts connected together shall not exceed the value in Table 4 specified value. When the shell is an insulating part, it should be wrapped with metal foil during the test. 5.7 Safety signs
5.7.1 The product nameplate should have the product model and name, the manufacturer's name or trademark, and the main parameters of the product. Table 4 Leakage current limit value
Product Category
Production
"Class 1 product with protective earth terminal directly connected in accordance with 5.6.7.2
Class product||tt ||Connection method
Figure 1
Figure 2
72
1 Accessible conductive parts; 2 Grid power supply; 3—Transfer switch leakage current limit I|| tt||mA
AC: 5 (peak) DC: 5
AC: 0.7 (peak) DC: 2
No leakage current test
Figure 1 and protection Leakage current measurement of Class I safety products with directly connected ground terminals GB16836—1997
团
1 - Accessible conductive parts or metal foil wound on the insulating shell: 2 - Grid power supply; 3 Conversion Switch; 4—Protective insulation; 5—Measurement grounding terminal Figure 2 Leakage current measurement of Class I safety products 5.7.2 The words, graphics, and symbols used on the product nameplate should be clear and legible, and should comply with the provisions of the corresponding national standards 5.7. .3 The opening and closing positions of the switch should be clearly marked. 5.7.4 The color of the indicator light and button should comply with the provisions of GB2682. 5.7.5 The color marking of the bare conductor should comply with the provisions of GB7947. The safety grounding wire should be yellow and green. . 5.7.6 Commonly used specific safety signs are shown in Table 5, and shall be marked on the product nameplate, corresponding parts of the shell or in the product manual according to actual needs
5.8 Information provided to users
Product manual. The relevant safety contents include the following: a) Product safety category (see 5.6.7~5.6.9); b) Connection method between protective ground terminal and accessible conductor or protective shield (only applicable to Class I safety products): c) The connection method between the protective ground terminal and the protective conductor (only applicable to Class I safety products); d) Power supply requirements of the product;
e) Shell protection level;
f) Safety signs;| |tt||g) Other instructions on safety requirements.
6 Inspection methods
6.1 Inspection of mechanical structure requirements
Use visual inspection according to the provisions of 5.1 ||tt| |6.2 Inspection of shell protection
According to the provisions of 5.2.3, test by the method specified in GB4208. According to the provisions of 5.2.4, use visual inspection
According to 5.3. The requirements of 3 and 5.3.4 shall be checked with calipers, tape measures or other linear measurement tools and visual inspection methods according to the provisions of 5.3.6 and the impulse voltage test method specified in GB7261 and GB/T14598.3. ||tt ||6.4.1 According to the provisions of 5.4.2, use a temperature measurement method (such as a thermocouple) to determine the temperature rise value. 6.4.2 For thermoplastic materials, use the Vikart method to measure the temperature rise; when the temperature rise rate is 50K/h, A force of 10N acts on a pressure rod with a cross-section of 1mm2. When the pressure rod penetrates 0.1mm into the thermoplastic material, the temperature at this time is the softening temperature of the material. 6.4.3 According to the provisions of 5.4.3, use linear measurement tools such as calipers and tape measures and visual inspection to check the electrical clearance and creepage distance, and measure the insulation resistance using the method specified in GB7261.
6.4.4 When there is doubt about the requirements of 5.4.4, a rigid test finger can be used to apply a force of 30N to each point on the product surface for 10 seconds. The product surface shall not undergo irrecoverable deformation. Category
Category
Power supply
Prompt
Safety level
Grounding
Symbol
DC
Exchange
2
(red)
?
back
-
h
sha
AC and DC
GB16836-1997
Table 5 Commonly used specific symbols
including
text
High voltage lightning touch hazard, used in applications with voltages higher than the ground Insulation voltage, generally greater than or equal to 1kV, high voltage hazard (accessories or instruments)
High temperature
Must refer to the instruction manual before operation
Class 1 safety product, with additional insulation or double Insulation general grounding
Protective grounding
Chassis grounding
Noiseless grounding
2, use temperature measurement methods (such as thermocouples) to determine the temperature rise value. 6.4.2 For thermoplastic materials, use the Vikart method to measure the temperature rise; when the temperature rise rate is 50K/h, a force of 10N is applied to a pressure rod with a cross-section of 1mm2. When the pressure rod penetrates 0.1mm into the thermoplastic material, this The temperature is the softening temperature of the material. 6.4.3 According to the provisions of 5.4.3, use linear measurement tools such as calipers and tape measures and visual inspection to check the electrical clearance and creepage distance, and measure the insulation resistance using the method specified in GB7261.
6.4.4 When there is doubt about the requirements of 5.4.4, a rigid test finger can be used to apply a force of 30N to each point on the product surface for 10 seconds. The product surface shall not undergo irrecoverable deformation. Category
Category
Power supply
Prompt
Safety level
Grounding
Symbol
DC
Exchange
2
(red)
?
back
-
h
sha
AC and DC
GB16836-1997
Table 5 Commonly used specific symbols
including
text
high voltage lightning touch hazard, used in applications with voltages higher than the ground Insulation voltage, generally greater than or equal to 1kV, high voltage hazard (accessories or instruments)
High temperature
Must refer to the instruction manual before operation
Class 1 safety product, with additional insulation or double Insulation general grounding
Protective grounding
Chassis grounding
Noiseless grounding
2, use temperature measurement methods (such as thermocouples) to determine the temperature rise value. 6.4.2 For thermoplastic materials, use the Vikart method to measure the temperature rise; when the temperature rise rate is 50K/h, a force of 10N is applied to a pressure rod with a cross-section of 1mm2. When the pressure rod penetrates 0.1mm into the thermoplastic material, this The temperature is the softening temperature of the material. 6.4.3 According to the provisions of 5.4.3, use linear measurement tools such as calipers and tape measures and visual inspection to check the electrical clearance and creepage distance, and measure the insulation resistance using the method specified in GB7261.
6.4.4 When there is doubt about the requirements of 5.4.4, a rigid test finger can be used to apply a force of 30N to each point on the product surface for 10 seconds. The product surface shall not undergo irrecoverable deformation. Category
Category
Power supply
Prompt
Safety level
Grounding
Symbol
DC
Exchange
2
(red)
?
back
-
h
sha
AC and DC
GB16836-1997
Table 5 Commonly used specific symbols
including
text
high voltage lightning touch hazard, used in applications with voltages higher than the ground Insulation voltage, generally greater than or equal to 1kV, high voltage hazard (accessories or instruments)
High temperature
Must refer to the instruction manual before operation
Class 1 safety product, with additional insulation or double Insulation general grounding
Protective grounding
Chassis grounding
Noiseless grounding
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