GB/T 4942.1-2001 Protection classification of rotating electrical machine enclosures (IP code)
Some standard content:
ICS29.160.01
National Standard of the People's Republic of China
GB/T 4942. 1 -2001
idtIEC60034-5:1991
Classification of degrees of protection providedby enclosures of rotating electrical machines(IP code)2001-07-12 Issued
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
2001-12-01 Implementation
GB/T 4942.1—2001
This standard is equivalent to the International Electrotechnical Commission standard IEC60034-5:1991 "Classification of degrees of protection providedby enclosures of rotating electrical machines (IP code)". This standard has revised GB/T 4942.1-1985. According to the provisions of GB/T 1.1 on standard compilation, "Chapter 2\Referenced Standards" has been added. Therefore, the numbers of the corresponding IEC Chapter 2 and subsequent chapters are all added with \1\. Compared with GB/I 4942.1-1985, the main changes in the technical content of this standard are as follows:
1. The original provisions of the symbol of Liu Ding climate-protected motors were that the letter W was immediately after IP, but now it is stipulated that the letter W is added after the second characterizing number.
2. In the general test requirements, the original provisions that the rated voltage of low-voltage motors does not exceed 1200V AC and the rated voltage of high-voltage motors exceeds 1200V AC are now changed to 1000V according to the provisions of 1FC600345:1991. 3. For the first characterization number 3, the conditions of the water spray test equipment were originally specified as 10 kPa of water pressure and 10 L/min of total water flow. Now the total water flow is changed to the average per hole (0.067~0.074) L/min multiplied by the number of holes. The original provisions for the test of climate-protected motors were determined by the manufacturer and the user. Now it is specified that the motor should have ventilation structure requirements and inspection requirements.
This standard was first issued in 1985. After the second revision, it will replace GB/T4942.1-1985 from the date of implementation. This standard is a recommended standard.
This standard is proposed by the State Machinery Industry Bureau. This standard is under the jurisdiction of the National Machinery Standardization Technical Committee. This standard was drafted by the Shanghai Electric Science Research Institute. The drafter of this standard is Zhai Zufang.
GB/T4942.1—2001
IEC Foreword
1) IEC's formal decisions or agreements on technical topics are drafted by technical committees with representatives of all national committees interested in the topic, and try to express international consensus on the topic. 2) Documents developed by technical committees for international application are recommended and accepted by national committees in this sense. 3) In order to promote international unification, IFC hopes that all national committees will adopt IEC recommended documents as their national standards when their national conditions permit. If there are any differences between the corresponding national standards and IEC recommended documents, they should be clearly stated in the national standards as much as possible.
This standard was drafted by IECTC2 Rotating Motors Section 2H (Protection Class, Cooling Methods and Installation Structure Types). The third edition of this standard replaces 1EC 60034-5 (2nd Edition): 1981 The content of this standard is based on IEC60034-5 (2nd Edition) and IEC529 (2nd Edition): 1989 "Enclosure Protection Classification (IP Code)" and the following documents:
June Legal Documents
2H(C0)17
2H(C0)18
Voting Report
2H(C0)20
2II(C0)21||tt| |The full voting information of this standard can be found in the above voting report: February Elimination Procedure
2II(C0)22
2H(C0)27
Voting Report
2II(C0)26 and 26A
2H(C0)28
1 Scope
National Standard of the People's Republic of China
Classification of degrees of protection providedby enclusures of rotating electrical machines(IP code) This standard applies to the classification of protection provided by enclusures of rotating electrical machines. 2 Referenced Standards
GB/T 4942. 1—2001
idt IEC 60034-5:1991
Replaces GB/T4942.11985
The provisions contained in the following standards constitute the provisions of this standard by reference in this standard. The versions shown are valid at the time of publication of this standard. All standards are subject to revision, and parties using these standards should explore the possibility of using the latest versions of the following standards. GB/T755--20) Ratings and performance of rotating electrical machines (idt. IEC 60034-1:1996) GB/T1993-1993 Cooling methods for rotating electrical machines (eqvIEC60034-6:1991) 3 Purpose
The purpose of this standard is:
a) To specify the standard level of protection applicable to rotating electrical machines: 1) To prevent human contact or proximity to live parts in the shell and contact with rotating parts in the shell (except for smooth indigo shafts and similar parts), and to prevent solid foreign objects from escaping into the electric field;
2) To prevent harmful effects caused by water in the motor;
b) To mark the level of protection;
c) To test the motor to meet the requirements of this standard. The requirements for shell protection specified in this standard must be followed. This standard only considers the enclosures that meet the design requirements in all aspects. Under normal use conditions, the materials and processing technology of the enclosures should ensure that their performance meets the requirements of this standard. This standard does not specify the degree of protection of the motor against mechanical damage or moisture (caused by condensation), corrosive gases, mold, insect pests, etc.; nor does it specify the degree of protection of the motor when it is running in an explosive gas environment. The fences set around the enclosure for personal safety only are not considered as part of the enclosure. 4 Marking
The symbol of the protection level consists of the symbol "IP" and the two symbol numbers attached to it. The meaning of the symbol numbers is shown in Table 1 and Table 2 respectively.
4.1 Single symbol number
When only one symbol number is needed to indicate a certain protection level, the omitted number should be replaced by the letter "X". For example, IPX5 or IP2X
4.2 Supplementary symbols
Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on July 12, 2001 and implemented on December 1, 2001
GB 4942.1—2001
When the protection content is increased, it is indicated by the additional letters after the second digit. If more than one letter is used, they are arranged in alphabetical order.
4.2.1 Symbols after the digits
For motors with special applications (such as open-circuit cooled motors installed on the deck of a ship, where the air inlet and outlet are closed when the machine is stopped), a letter may be added after the digit to indicate whether the test to prevent the harmful effects of water ingress is carried out when the motor is stationary (with the letter S) or running (with the letter M). In this case, the degree of protection of the motor in any state should be indicated, for example, IP55S/IP20M. If there are no letters S and M, it means that the specified degree of protection is applicable under all normal use conditions. 4.2.2 For open air-cooled motors suitable for specified climatic conditions and with additional protective features or measures (see the provisions of Chapter 11), the letter W is used to indicate it.
4.3 Marking examplesWww.bzxZ.net
Symbol letters
First digit
(See Table 1)
First digit
(See Table 2)
5 Protection level---First digit
5.1 The first digit indicates the level of protection against people and parts inside the shell. The third column in Table 1 shows the details of the objects that the protection level represented by the first digit can "prevent" from entering the shell. The term "prevent" means that part of the human body, tools or wires held by the user can be prevented from entering the shell. Even if they enter, they can maintain a sufficient gap between them and the live or dangerous rotating parts (except smooth rotating shafts and similar parts). The third column in Table 1 also indicates the size of the smallest solid foreign objects that can be prevented. 5.2 In the table, the enclosure that complies with a certain degree of protection implies that it also complies with all lower degrees of protection. Unless in doubt, it is not necessary to test the lower degree of protection.
5.3 External fan
To prevent contact with the blades and spokes of the external fan, the enclosure shall comply with the following requirements: Degree of protection of the motor
IP2X to IPSx
During the test, it is used for slowly rotating rotors. Smooth shafts and similar parts are slightly tested for their hazards. Sincerity
50mm test ball test
Test finger test
Note: For applications requiring protection against accidental or intentional contact (such as meter or household use), the protection requirements for external fans may be increased as needed. 5.4: Drain holes
If the motor is equipped with drain holes, it shall comply with the following requirements: During the test, the drain holes intended to be open at the installation location shall remain open. During the test, the drain holes intended to be closed at the installation location shall remain closed. For motors with protection level of IP3X or IP4X and whose drain holes are open during operation, the protection level of the drain holes can meet IP2X. For motors with protection level of IP5X1 and whose drain holes are open during operation, the drain holes can meet IP4X.2
First characterization
Note (2)
Note (2)
Note (2)
Note (3)
Brief descriptionNote (1)
Unprotected motors
Motors with protection greater than 50 mm solid
Motors with protection greater than 12 mm solid
Motors with protection greater than 2.5 mm solid
Motors with protection greater than 1 mm solid
Dust-proof motors
GB 4942. 1—2001
Table 1 The first characterizing number indicates the degree of protection against expansion Degree of protection against expansion
No special protection
Can prevent a large area of human body (such as hand) from accidentally damaging the outside and or approaching the live or rotating parts in the shell (but cannot prevent intentional contact) Can prevent solid foreign objects with a diameter greater than 50 mm from entering the shell Can prevent fingers or similar objects with a length of no more than 80 mm from touching or approaching the live or rotating parts in the shell
Can prevent solid foreign objects with a diameter greater than 12 μm from entering the shell Can prevent tools or wires with a diameter greater than 2.5 mm from touching or approaching the live or rotating parts in the shell
Prevent solid foreign objects with a diameter greater than 2.5 mm from entering the shell Can prevent wires or strips with a diameter or thickness greater than 1 mm from melting or approaching the live and rotating parts in the shell
Can prevent Solid foreign matter can be prevented from entering the shell. It can prevent contact with or approach to the live or rotating parts in the shell. Although it cannot completely prevent dust from entering, the amount of dust entering is not enough to affect the normal operation of the motor. Note: (1) The "Brief Description" column in this table is not used as a regulation of the protection type. The test conditions are not tested. (2) The solid foreign matter that can be prevented by the motor with the first characterization number from 1 to 4 includes objects with regular or irregular shapes, and their three mutually multiplied dimensions exceed the corresponding values specified in the "Meaning" column. (3) Level 5 dust protection is general dust protection. When the particle size, fibrous or granular form of the dust has been specified, the test conditions should be determined by negotiation between the manufacturer and the user. 6 Protection Level 1 Second Characterization Number 6.1 The second characterization number indicates the protection level against harmful effects caused by water entering the shell: The first column in Table 2 shows the details of the protection type of the shell for each protection level represented by the first characterization number. For open motors designed as weather-proof air-cooled, under specified climatic conditions, the ingress of rain, snow and airborne particles is reduced to a certain amount to adapt to normal operation. This degree of protection is marked by the letter W after the second characterizing number. 6.2 In Table 2, an enclosure that meets a certain degree of protection means that it also meets all service levels lower than that degree of protection. Unless there is doubt, it is not necessary to test for a higher degree of protection.
First characterization
Unprotected motor
Drip-proof motor
15° drip-proof motor
Spray-proof motor
Splash-proof motor
Spray-proof motor
Wave-proof motor
Water-proof motor
Submersible motor
GB 4942.1:2001
Table 2: Degree of protection indicated by the second digit Protection level
No special protection
Vertical full water shall have no harmful effect
When the motor is tilted from the normal position to any angle within 15\ in any direction, vertical dripping water shall have no harmful effect
Water within an angle of 6\ with the vertical shall have no harmful effect Splashing water from any direction shall have no harmful effect Spraying water from any direction shall have no harmful effect When water is sprayed, the amount of water entering the motor should not reach a harmful level.
When the motor is immersed in water of specified pressure for a specified time, the amount of water entering the motor should not reach a harmful level.
The motor can be submerged for a long time under the conditions specified by the manufacturer. The motor is generally watertight, but water can be allowed to enter certain types of motors, but it should not reach a harmful level. Note: The "Brief Description" column in this table is not used as a regulation for the protection type. 7 Marking method
The letters and numbers representing the protection level should be marked on the nameplate of the motor. If necessary, it can be marked on the shell test conditions
No test
When the various parts of the motor have different protection levels, the lowest protection level should be marked first. If other parts need to be marked, they should be marked according to the protection level of the part.
When the installation method of the motor affects its protection level, the manufacturer should explain the intended installation method on the nameplate, installation instructions and other relevant documents.
8 General test requirements
The tests specified in this standard are type tests. The tests shall be carried out on standard products or their models. When this is not feasible, the acceptance by test verification or drawing review shall be agreed upon by the manufacturer and the user.
Unless otherwise specified, the prototype for each test shall be a clean new product, all parts shall be in place and installed in the manner specified by the manufacturer.
For the protection levels with the first characterizing digit being 1 and 2, and the first characterizing digit being 1, 2, 3 and 4, if visual inspection can determine that the required protection level is achieved, no further testing is required. However, if there is any doubt, tests may be carried out in accordance with Chapters 9 and 10. 8.1 Sufficient clearance
In the following test clauses of this standard, the term "sufficient clearance" has the following meaning. 8.1.1 For low-voltage motors (rated voltage of AC not exceeding 1000V and DC not exceeding 1500V), except for non-hazardous parts such as smooth rotating shafts, the test tool (test ball, test finger or wire, etc.) should not touch the live or rotating parts. 8.1.2 For high-voltage motors (rated voltage of AC exceeding 1000V and DC exceeding 1500V). When the test tool is placed in the most unfavorable positions 1, the motor should be able to withstand the withstand voltage test applicable to the motor. The withstand voltage test can be replaced by measuring the air gap size between the test tool and the live parts in the shell. The gap size should ensure that the motor passes the withstand voltage test under the most unfavorable electric field distribution. 4
9 Test of the first characterizing number
GB 4942. 1—2001
The test and approval conditions for the first characterizing number shall be in accordance with the provisions of Table 3. Table 3 Test and approval conditions for the first characterizing number The first characterizing number
Test and approval cases
No test required
Use a rigid test ball with a diameter of 509:%1I: to apply a force of 45N~55N to each opening part of the housing for testing. If the test ball fails to pass through any opening part and maintains sufficient spacing with live or rotating parts in the motor during operation, it is considered to meet the protection requirements
a) Test finger test:
Use the metal test finger shown in Figure 1 for testing. The two joints of the test finger can be bent 90° in the same direction around its axis. Use no more than 10 The test finger is pushed to the opening parts of the shell with a force of N. If it can enter the shell, it should be moved to all possible positions. If the test finger maintains sufficient clearance with the live or rotating parts in the shell, it is considered to meet the protection requirements. However, it is allowed to connect the test finger to a smooth rotating shaft and similar non-hazardous parts. During the test, the rotating parts in the shell should be rotated slowly. When testing low-voltage motors, a low-voltage power supply with an appropriate indicator light can be connected between the test finger and the live parts in the shell (not less than 40V). For conductive parts coated with varnish, paint, oxide and similar methods, metal foil should be used, and the metal screen should be connected to the live parts during operation. If the indicator light does not light up during the test, it is considered to meet the protection requirements. When testing high-voltage motors, use a withstand voltage test to check for sufficient clearance or measure the gap according to the principles of 8.1.2. b) Test ball test:
Use a ball with a diameter of 12. )-:A rigid test ball with a diameter of 2.5 mm is used to apply a force of 27 N to 33 N to the outer shoulder part. If the test ball cannot pass through the opening part, and the part that enters maintains sufficient clearance with the live or rotating parts in the motor, it is considered to meet the protection requirements. A straight hard steel wire or rod with a diameter of 2.5 + 3 mm is used to apply a force of 2.7 N to 3.3 N. The end face of the steel wire or rod should be free of burrs and perpendicular to the wire. If the steel wire or rod cannot enter the shell, it is considered to meet the protection requirements. A straight hard steel wire or rod with a diameter of 11 g: 25 mm is used to apply a force of 0.9 N to 1.1 N. The end face of the steel wire should be free of burrs and the axis should be perpendicular. If the steel wire or rod cannot enter the shell, it is considered to meet the protection requirements. a) Dustproof test: The basic principle is shown in Figure 2. The equipment required is tested. In a properly sealed test box, there is talcum powder in suspension. The talcum powder should be able to pass through a metal square sieve with a mesh size of 75um and a wire diameter of 50um. The amount of talcum powder is 2k per cubic meter of the test box volume, and the number of uses should not exceed 20 times. The motor housing belongs to the first type of housing, that is, during normal operation, the pressure inside the housing is lower than the ambient pressure due to thermal effects. During the test, the motor supports the test box and uses a vacuum pump to evacuate the air inside the motor housing to lower the ambient pressure. If the housing has only one drain hole, the exhaust pipe shall be connected to the hole opened for the test, except for the drain hole that is closed at the operating location (see 5.4).
First characterizing digit
GB4942.1-2001
Table 3 (end)
Test and approval conditions
The test is to use an appropriate pressure difference to draw the internal air into the motor. If possible, the exhaust volume is at least 80 times the internal air volume of the housing. The exhaust rate should not exceed 60 internal air volumes per hour. In any case, the pressure difference on the pressure gauge should not exceed 2kP (20mhar). If the exhaust rate reaches 40 to 60 times the internal air volume per hour as shown in the pressure gauge in Figure 2, the test is carried out for 2 hours. If the exhaust speed is lower than 40 times the volume of air in the shell per hour and the pressure difference reaches 2kPa (27mbar), the test shall be continued until 80 times the volume of air in the shell is exhausted or the test lasts for 8 hours. If the whole motor cannot be placed in the test chamber for testing, any of the following methods may be used as a substitute: Use the independent parts of the motor housing, such as the junction box, collector ring cover, etc. for testing; Use representative parts of the motor, such as doors, vents, joints or shaft seals for testing. During the test, the parts installed in the weak seal position of these components, such as terminals, collector rings, etc., should be installed in place. A smaller motor with the same structural proportions as the test motor should be used for the test. The test should be carried out under the conditions agreed upon between the manufacturer and the user. For the above methods 2 and 3, the volume of air drawn into the motor during the test should be the value specified for the original motor. After the test: If there is no large accumulation of talcum powder, and its deposition location is not sufficient to affect the normal operation of the motor like other dusts (such as non-conductive, non-flammable, non-explosive or non-chemically corrosive dusts), it is considered to meet the protection requirements. b) Steel wire test: If the drain hole is opened during the operation of the motor, the test should be carried out according to the test method with the first characterizing digit being 4, using a steel wire with a diameter of 1 mm. 10 Test for the second characterizing digit 10. 1 Test conditions The test conditions for the second characterizing digit shall be as specified in Table 4. The test should be carried out with clean water.
During the test, moisture inside the shell may partially condense. Avoid mistaking condensed dew for water ingress. According to the test requirements, the error in surface area calculation should not exceed 10%. Adequate safety measures should be taken when testing the motor with power on. Table 4 Test conditions for the second characterizing number First characterizing number
Test conditions
Particularly required tests
The test is carried out using a dripping device, the principle of which is shown in Figure 3. The dripping water should be evenly distributed over the entire area of the equipment and can produce a rainfall of 3mm to 5mm per minute (if a device equivalent to Figure 3 is used, the water level drops by 3nml to 5mm per minute)
The motor under test is connected to the normal operating position and is changed below the dripping device. The bottom of the device should be larger than the motor under test. Except for motors intended to be mounted on a wall or ceiling, the support of the motor under test shall not be less than the bottom of the motor. For motors mounted on ceilings or ceilings, they shall be mounted on a wooden board in a normal convenient position. The size of the wooden board shall be equal to the contact area between the motor and the wall or ceiling in normal use. Test time is 10 min. Second characterizing digit GB 4942. 1-2001 Table 4 (continued) Test equipment Water dripping equipment and rainfall are the same as for level 1 Test for 2.5 min at each of the four fixed inclined positions of the motor. These four positions are inclined by 15″ from the vertical line on two mutually perpendicular planes. The total test time is 10 min. When the size and shape of the motor under test can be accommodated under the oscillating pipe with a radius not exceeding 1 m as shown in Figure 4, this equipment shall be used for the test. If this is not possible, the test equipment shown in Figure 5 shall be used. a) Test conditions when using the equipment shown in Figure 4
The total flow rate should be adjusted to an average of (0.067 ~ 0.074) L/min per hole multiplied by the number of holes. The total flow plate should be a flow meter measuring tube with water spray holes arranged in an arc segment of 60° on both sides of the center point. The plate is fixed in a vertical position. The motor under test is placed on a turntable and close to the center of the semicircular swing pipe. The turntable system rotates its vertical axis at an appropriate degree so that all parts of the motor are wetted during the test
The test time is at least 10 min
h) Test conditions when using the equipment shown in Figure 5
The movable baffle should be installed during the test
The water pressure is adjusted to a water flow rate of (9.5 ~ 10.5) L/min + a pressure of about 80 kPa ~ 100 kPa (0.8 bal ~1.Ohar)
Test time: 1 min per square meter of the surface area (excluding any installation area) calculated by the beryllium test motor; but at least 5 min
The conditions of the equipment in Figure 4 or Figure 5 are the same as those of Level 3a) Test equipment when using the equipment in Figure 4:
The pipe should be full of water spray holes in a semicircle of 180°. The test time, turntable speed and total water flow are the same as those of Level 3. The support of the tested motor should be perforated to avoid blocking the water flow. The swing pipe swings to the maximum limit at a speed of 60°/ to each side, so that the motor is sprayed in all directionsb) Test conditions when using the equipment in Figure 5: Remove the movable baffle of the sprinkler. The motor is sprayed in all directions. The spray rate and the spray time per unit area are the same as those of Level 3. Use the standard spray shown in Figure 6 for testing. The water jet from the nozzle sprays the motor from all possible directions. The conditions to be observed are as follows:
Nozzle inner diameter: 6.3 mm
Water flow rate: (11, 9~13.2)L/min
Nozzle water pressure, about 30kPa (0.3bar) (see Wang 1) Test time: 1 min for every half meter of the surface area calculated for the test motor, but at least 3in Nozzle distance: about 3 m from the surface of the test motor (see Note 2) (If necessary, this distance can be shortened to ensure appropriate injection volume when spraying the motor upwards) The test equipment is the same as the first and second levels. The conditions to be observed are as follows: Nozzle inner diameter: 12.5 mm
Water flow rate: (95～105)L/min
Nozzle water pressure: about 100kPa (1bar) (see Note 1)Test time: 1min per square meter of surface area calculated according to the tested motorMinimum test time: 3min
Nozzle distance: 3m from the surface of the tested motorSee Note 2)Second characterizing number
GB 4942.1—2001
Table 4 (end)
Test conditions
The motor is completely mixed in water for test and meets the following conditions:a) The water surface should be at least 150mm above the top of the motorh) The bottom of the motor should be at least 1m below the water surfacec) The test time is at least 3Cmin
d The temperature difference between water and motor should not be greater than 5 K If the manufacturer and the user reach an agreement, the test can be replaced by the following method: fill the motor with air to make the air pressure 10kPa (0.1bar) higher than the external pressure. The test time is 1min. If no air comes out, it is considered to meet the requirements. The method for checking air leakage is to completely immerse the motor in water or apply soapy water on the motor surface. The test conditions shall be in accordance with the agreement between the manufacturer and the user, but shall not be lower than the requirements of level 7. 1. The measurement of water pressure can be replaced by the water pressure sprayed out of the nozzle: Water pressure: 30 kPz (c. 3 bar)
Water pressure:10u kPa (1 ber)
Height: 2.5m
Height: 8m
2 For level 5 and level 6, the distance from the nozzle to the motor under test is specified to be 3m. In order to spray the motor from every direction, this distance can be appropriately shortened. 10.2 Approval conditions
After the test according to Table 4, the water ingress of the motor should be checked and the following inspections and tests should be carried out. 10.2.1 The amount of water ingress into the motor should not be sufficient to affect the normal operation of the motor; the windings and live parts that are not intended to operate under humid conditions should not be wet, and the accumulated water in the motor should not affect these parts. The wind turbine blades inside the motor are allowed to be wet: at the same time, if there are drainage measures, water is also allowed to leak along the shaft end. 10.2.2 If the motor is tested in a stationary state, it should be operated at no load for 15 minutes at the rated voltage before the withstand voltage test. The test voltage should be 50% of the test voltage of the new motor, and should not be less than 125% of the rated voltage. If the motor is tested in the rotating state, the above-mentioned withstand voltage test can be directly carried out. If the motor meets the requirements of GB/T755 without damage after the test, it is considered to have passed the test. 11 Tests and requirements for open-type climate-protected motors. Open-type motors with protection level W are used for open-circuit cooling, that is, motors with cooling methods coded as ICOX to IC3X according to GB/T1993.
Climate-protected motors should be designed to reduce the entry of rain, snow and airborne particles into the motor. For motors with other climate protection measures (encapsulated windings or fully enclosed), it is not necessary to mark W. The ventilation structure of motors with protection level W should be: a) At the outlet and outlet, high-speed air and airborne particles are blocked from entering the internal air path directly to the live parts of the patrol machine; b) In the air inlet circuit, the baffle or isolation cover has at least 3 sudden changes in direction for the entry of air, each of which is at least 90°; c) The area of the air inlet circuit is such that the average wind speed does not exceed 3ⅡI/s. Any airborne particles can be precipitated. To separate the particles, a removable or other easily cleanable filter or any other structure may be used instead of a settling chamber. The protection of the motor against contact and water shall comply with the conditions and tests of the degree of protection specified in this standard. The design of the terminal box shall ensure at least I51c. If necessary, structural arrangements shall be made by agreement for protection against icing, moisture, corrosion or other abnormal conditions (such as anti-condensation heat).
For the inspection of weather protection W, it is usually sufficient to check the drawing. 8
Dimensions: mm
GB 4942.1—2001
1: handle + 2: baffle; 3: insulation material; 4: stop surface; 5: connection; 6: all edge angles; 7: R2±0.05 round shape; 8: R4±0.05 spherical shape 0
Dimensional tolerances for unspecified tolerances: Angle: 10
Straight dimension, 25 and below:
25 and above: ±0. 2
Test finger material: heat-treated steel
The two connection points of the test finger can be bent within the range of 90+1, but only in the same direction. The connection with pins and holes is only a possible way to quickly achieve a bending angle close to 90\. Therefore, its dimensions and tolerances are not given in the drawing. The actual design must ensure a 90° bending angle, and its tolerance is 0° stem 10°. Figure 1 Standard test finger
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