GB/T 14823.2-1993 Special requirements for conduits for electrical installations - Rigid insulating material flat conduits
Some standard content:
National Standard of the People's Republic of China
Conduits for electrical installations
Special requirements
Rigid plain conduits of insulating materials forelertrical Instailations
CB/T 14823.293
This standard adopts IEC614-2-2 (1980) "Technical requirements for conduits for electrical installations Part 2: Rigid plain conduits with special requirements".
Subject content and scope of application
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of rigid plain conduits of insulating materials forelertrical Instailations (hereinafter referred to as conduits) for electrical installations. This standard applies to rigid plain conduits of insulating materials with a circular cross section used to protect wires and cables in electrical installations of 1000V and below. www.bzxz.net
2 Reference standards
GB/T13381·1 General requirements for conduits for electrical installations GB5169·1 Terminology of fire hazard tests for electrical and electronic products GB1801 Tolerances and fits Tolerance zones and fits of holes and shafts up to 500mm GB192
Basic tooth profiles of common threads
Basic dimensions of common threads (diameter 1~～600mm) GB 196
GB 197
GB 3934
Tolerances and fits of common threads (diameter 1~～355mm) Common thread gauges
GB 2828
Batch inspection counting sampling procedure and sampling table (applicable to the inspection of continuous batches) GB2829
Periodic inspection counting sampling procedure and sampling table (applicable to the inspection of the stability of the production process) 3 Terminology
3.1 Burn (combustion)
The oxidation exothermic reaction of a substance, accompanied by the generation of flames, heat and (or) smoke. 3.2 Flame
The gas phase combustion area with light.
3.3 Glow
The solid material generates heat and light at the same time after being heated without combustion or other chemical reactions. 4 Classification and performance marking
4.1 Classification
Approved by the State Administration of Technical Supervision on December 30, 1993 and implemented on October 1, 1994
4.1.1 Classification by mechanical properties
GB/T 14823.293
Conduits that can withstand small mechanical stress (referred to as "lightweight tubes"), conduits that can withstand medium mechanical stress (referred to as "medium-duty tubes"): conduits that can withstand large mechanical stress (referred to as "heavy-duty tubes"). 4.1.2 Classification by the ability of conduits to resist combustion: a,
Combustible conduits;
Non-combustible conduits.
4. 1.3 Classification by temperature, as shown in Table 1. Table 1
Temperature classification
+90/25
Usual temperature
In storage, transportation
In installation and use
Note: 1) Type of conduit, when used in prefabricated filter soil, will be subjected to a short temperature of +90C. 4.2 Marking
4.2.1 The conduit should be marked with:
Manufacturer's name, trademark or other identification symbols: model, outer diameter size;
A performance mark in accordance with A1 in Appendix A; in addition, it is also marked with an additional performance mark in accordance with A2 in Appendix A. Long-term use temperature
—15~+60
-15~+60
-10~+60
-5~+60
5~+601
15~+60
The first mark is about 50mm from the end of the catheter, and the mark should be re-made on the catheter every 1~3ml. 4.2.2
4.2.3 The order of the mark is as follows:TA
Outer diameter size
Beijing XXXI
Manufacturer name (or trademark)
The entire mark indicates the inner wear:
325/1200001
Performance digital
The TA type produced by Beijing XXX factory has an outer diameter of 40mm and can withstand medium machine Mechanical stress, temperature level is -25℃, suitable for additional insulation, and flame-resistant rigid insulating material flat conduit. The meaning of performance numbers is shown in Appendix A.
4.2.4 Marking should be durable, easy to identify and clear 4.2.5 Marking can be made by molding, printing, printing, adhesive label, watermark transfer and other methods. 5 Structure and size
5.1 Size ("nominal size")
5.1.1 The outer diameter and tolerance of the conduit shall comply with the corresponding provisions of the "conduit outer diameter size" and "outer diameter tolerance" items in Table 2, and its minimum outer diameter shall not be less than the corresponding provisions of the items in Table 3 (see Figures 1 and 2). 5.1.2 The minimum inner diameter of the catheter when subjected to external force shall not be less than the corresponding provisions of "minimum inner diameter 4" in Table 2 (see Figure 1). Catheter outer diameter size
Minimum inner diameter
Outer diameter tolerance
Maintenance material: polished steel.
Catheter outer diameter size
CB/T 14823.2—93
Catheter minimum inner diameter
Wheel capsule resistance figure
Manufacturing tolerance:
Allow loss 0.(lmm.
Figure 2 Gauge for checking the minimum outer diameter of the catheter
Manufacturing tolerance
-- 0. 022
Allowable wear
5.1.3 The minimum inner diameter of the conduit after bending should be able to pass through the corresponding inner diameter D item in Figure 3 and Table 4. 63
GB/T 14823.2—93
Material: solid polished steel, with slightly rounded edges all around. 0.9D
一0.05mm. Axial dimension tolerance: +0.2mm. Allowable wear: +0.01mm. Manufacturing tolerance,
Figure 3 Gauge for checking the minimum inner diameter of the catheter after bending Table 4
Catheter outer diameter gauge
Light pipe
Medium pipe
Heavy pipe
5.1.4 The thread profile of the catheter shall comply with the provisions of GB192. 5.1.5 The catheter thread is a fine thread with a pitch of 1.5mm. The thread detail size shall comply with the provisions of the corresponding size of GB196. 5.1.6 The tolerance and fit of the catheter thread shall comply with the provisions of GB197. The tolerance grade of each diameter of the external thread is grade 8, The tolerance grade of each diameter of the internal thread is 7.
5.1.7 The manufacturing length of the conduit is usually 4m, and the tolerance of the manufacturing length is ±20mm. 5.1.8 In addition to the size specifications of this standard, the various sizes of the conduit and its manufacturing length shall be agreed upon by the supply and demand parties. Note: When there are special standards for the size and thread of the conduit, this standard should be adopted. 5.2 Appearance and structure
5.2.1 The inner and outer surfaces of the conduit should be flat, without obvious defects such as bubbles, cracks and uneven color: the reverse edge of the pipe mouth should be smooth and will not damage the insulation layer of the wire and cable.
5.2.2 A few burrs formed due to manufacturing can be ignored if they do not damage the wire or cable. 5.2.3 The wall thickness of the conduit should be uniform. After the wall thickness uniformity test in 7.4.3, the wall thickness uniformity should meet the following formula: IM. - MI ≤ 0.1M + 0.1mm (i = 1,2,3--..--12) M
measured value of each wall thickness, 12 in total;
Xi——average value of 12 measured values,
6 Technical requirements
6.1 Mechanical properties
6.1.1 Compression resistance
GB/T14823.2 93
After the pressure test in 7.5.1, the difference between the original outer diameter and the outer diameter before the pressure is evacuated shall not exceed 25% of the original outer diameter
After the pressure is released for 1 minute, the difference between the original outer diameter and the outer diameter at the compressed fan shall not exceed 10% of the original outer diameter. After the pressure is evacuated, the catheter shall not have visible cracks. 6.1.2 Impact resistance
After the 12 conduits are subjected to the impact test in 7.5.2, at least 9 of them have no visible cracks or damage. 6.1.3 Bending resistance
After the conduits with an outer diameter of 16 or 20.25 mm are subjected to the bending test in 7.5.3, no visible cracks should appear on their surfaces. 6.1.4 Bending resistance
After the conduits with an outer diameter of 16 or 20.25 mm are subjected to the bending test in 7.5.After the bending test, there shall be no visible cracks on the outer surface. The gauge of the corresponding size in item D of Table 4 of Figure 3 shall be able to pass through the catheter under the action of its own weight without initial velocity. 6-2 Heat resistance
After the catheter is subjected to the ball pressure heat resistance test of 7.6, the diameter of the indentation shall not be greater than 2mm. 6. 3 Flame resistance performance
After the duct is subjected to the flame resistance test in 7.7, it shall meet the following requirements: "a. The duct is not burning:
b. Although the duct is burning, the flame and heat can be automatically extinguished within 30 seconds after the fire source leaves, and the silk paper underneath is not on fire and the pine board is not burnt.
Note: Net paper is a soft and tough lightweight packaging paper with a specific gravity in the range of 12 to 30g/m*. 6.4 Electrical insulation performance
After the duct is subjected to the electrical insulation test in 7.8, there is no breakdown or flashover phenomenon, and the insulation resistance of the duct is not less than 100M0. 7 Test method
7.1 General requirements
7.1.1 The duct should be Carry out type tests within 10 days (including the 10th day) of manufacturing. 7.1.2 Unless otherwise specified, the test is usually carried out at room temperature. In case of dispute, the test is carried out at 25±5°C. 7.1.3 Unless otherwise specified, each type test shall be carried out on three specimens. Three tubes are randomly selected, and specimens for various tests are cut from these tubes. Each tube provides one specimen for each test. 7.2 Mark inspection
Wipe the mark with a piece of cloth fully soaked in water at a speed of 2 times/s (the forward and backward movements of the hand are counted as 1 time each) for 15 seconds, then wipe it with a piece of cloth fully soaked in gasoline at the same speed for 15 seconds, and then inspect according to the requirements of Article 4.2. 7. 3 Size inspection
7.3.1 The outer diameter of the conduit is measured with a vernier caliper with a graduation value of not less than 0.02mm1. 7.3.2 The gauge for measuring the minimum inner diameter of the conduit, its shape and detailed dimensions are shown in Figure 4 and Table 5; when measuring the conduit of the corresponding size, the conduit that can pass the gauge without any external force and initial velocity is qualified. Conduit outer diameter gauge
Light pipe
Medium pipe
Heavy pipe
GB/T 14823.2-93
Material: polished steel. Manufacturing tolerance, +.05mm. Allowable wear: 0.01mm.
Figure 1 Gauge for checking the minimum inner diameter of flat conduits
7. 3. 3 Gauge for measuring the minimum outer diameter of the conduit, its shape and detailed dimensions are shown in Figure 2 and Table 3 As shown in Figure 3, when measuring the corresponding size of the conduit, the conduit that cannot pass the gauge without any external force is qualified. 7.3.4 The shape and detail size of the gauge for measuring the minimum inner diameter of the conduit after bending are shown in Figure 3 and Table 4. When measuring the corresponding size of the conduit, the conduit that can pass the gauge without any external force and initial velocity is qualified. 7.3.5 The thread and detail size of the conduit are measured with a gauge that conforms to GH3934 and appropriate measuring tools. 7.3.6 The measurement of the wall thickness M of the conduit is the same as in 7.4.3. 7.3.7 The length of the conduit is measured with a steel tape measure with an accuracy of not less than 0.5mml. 7.4 Appearance and structure inspection
Use visual inspection and measuring tools with appropriate accuracy to inspect the appearance quality and structure of the conduit. 7.4. 1
7.4.2 If necessary, the sample can be cut and inspected longitudinally. 7.4.3 Check for uniformity of wall thickness: Generally, it can be measured daily: If there is any doubt, three samples can be taken from different sections of the same conduit (cut along the vertical axis), and then measured at four positions on the circumference of each cut with a wall thickness ruler or a measuring tool of appropriate accuracy, where the unit position is the thinnest part of the tube wall. There are 12 values measured in total, and their average value M is calculated. Check their uniformity according to formula (1). 7.5 Mechanical properties test
7.5.1 Bed force test
Take 3 samples with a length of 200 lum, first measure their outer diameter D1, and place them horizontally at room temperature. After 10 hours, place the samples on the steel plate as shown in Figure 5, and place a square steel block on the middle of the sample. Apply a slowly increasing force F to the steel block, which should reach the value shown in Table 6 within 30 seconds. Measure the outer diameter D of the flattened part without removing the pressure for 1 minute. The difference between D, should not be greater than 25% of D,
Remove the pressure and the steel block for 1 minute and then measure the outer diameter 1);;1) of the flattened part of the sample. The difference between D, should not be greater than 10% of D,. Then: Check whether there is any crack on the surface of the sample. Sample
Vehicle support
Force type
7.5.2 Impact test
GB/T 14823.2—93
Steel block
Figure 5 Arrangement of pressure test
Applied pressure F
Put 12 specimens of 200 mm in length in an oven at 60±2℃. After 240 hours, take them out and put them in a freezer. The temperature in the freezer is shown in Table 7:
Tube types (divided by temperature)
-5 and 90 types
-25 and 90/·25 types
Freezer temperature
—5±1
-15±1
-45±1
When the specimen reaches the temperature of the freezer or has been placed for 2 hours (whichever is longer), take out the specimen (only one specimen is taken at a time), put the specimen on the steel support shown in Figure 6, and make the hammer fall and impact (the time from taking out the specimen to the hammer falling and impacting should be controlled within 10 seconds). The impact height and hammer weight are shown in Table 8.
Copper support pressure (10kg)
GB/T14823.2—93
Spacer steel block
Image cavity fastener (thickness mm)
Light spot setting
Force type
AB side
(100g]
Figure 6 Impact test arrangement
After the test, at least 9 samples should have no cracks or bends. 7.5.3 Cross-bend test
Fall height
FFall height
100±1
For a conduit with an outer diameter of 16.20 and 25mm, use 6 500mm long samples for bending test. Before the test, insert a bending aid into each sample. The bending aid can be a dense coil spring (spring) made of burr-free steel wire with a diameter of 1 to 2mm. The outer diameter is 0.7-1 Ⅱm smaller than the specified minimum inner diameter of the catheter). Or use the bending auxiliary parts recommended by the manufacturer.
Three samples are tested at room temperature,
The other three samples are placed in a freezer. After the sample temperature reaches the freezer temperature or 2 hours (the longer time), take them out for testing.
The freezer temperature is shown in Table 9.
GB/r14823.2-93
The catheter type is
5 type, 190, one 15 Type
Other types
Refrigerator temperature
—5+2
The shape and detailed dimensions of the bending test device are shown in Figure 7 and Table 10. Place each specimen in the position shown in Figure 7 and gently clamp it in the middle of the forming die with a clamp. Move the bending roller around the forming die so that the total bending angle of the specimen is about 180°, so that when the die is released, the specimen can be bent to an angle of 90°. At this position of 90°, the bending auxiliary parts should be removed without damaging the specimen and the bending auxiliary parts. After the test, observe whether the specimen has cracks. Common frequency device
Die for real bending
Bending spring
Outer diameter of catheter
7.5.4 Bending test
Bottom of forming die groove
Radius t
Bending test Inspection of cloth trade
Bending roller center
Trace radius R:
Forming die and bending
Roller groove radius:
Bending radial groove
Bottom radius
A specimen with an outer diameter of 16.20.25mm (length 500mm) is bent into a 90-degree angle without bending auxiliary parts according to 7.5.3. The specimen is fixed on a rigid support using the device shown in Figure 8. The specimen and the support are placed in an oven at a temperature of 60±2℃ for 24 hours and then taken out. The straight part of the specimen is at a 45-degree angle to the plumb line. A gauge that meets the size of item D" in Figure 3 and Table 4 is placed. The passing condition is observed according to the requirements of 6.1.4, and the degree of surface damage is checked.
7.6 Ball pressure heat resistance test
GB/T14823.2—93
Negative upper object
Bending test arrangement
Three 80mm long catheters are cut in half along the long axis, and one of the three pieces is taken as the sample. They are placed horizontally on the steel support one by one, as shown in Figure 9. Then the steel support and the sample are placed in an oven with a temperature of 60±2℃. When the steel support and the sample reach the oven temperature, a ball with a diameter of 5mm is pressed on the inner surface of the sample with a force of 20N. After 1h, the steel ball is removed and the sample is taken out. After the sample temperature drops to room temperature, the diameter of the repulsion mark is measured. 2
Figure 9 Ball pressure heat resistance test arrangement
7.7 Flame resistance test
The flame resistant catheter is tested with three 675±25mm long samples. The test is carried out in still air. The flamethrower is a Bunsen burner with a nozzle inner diameter of 9~10mII. The flame is produced by propane gas. The gas volume should be able to make the flame at the specified diameter. The energy generated by the Bunsen burner is 900+30W. Let the Bunsen burner be placed in a vertical position and adjust the flame to a total length of 100mm and a blue flame core length of 50mm. Tilt the Bunsen burner so that its axis is at an angle of 45° to the vertical direction and then conduct the test. The test arrangement is shown in Figure 10 and the burning time is given in Table 11. Steel falling
Bunsen burner
Wrapped with a layer of paper about [0mm-
thick
Figure 10 Combustion test arrangement
Note: When the outer diameter of the conduit is 25mm or less, the steel diameter is 6o. Iram l When the outer diameter of the conduit is greater than 25mm, the steel diameter is 16±0.1mm. Table 11
Wall thickness of conduit
7.8 Electrical insulation test
Standard
Burning time
Continuous 3 times, 25 each time, interval 5
once, 80
once, 125
7.8.1 For conduits with an outer diameter not exceeding 25m, cut 3 1.2m long sections as samples, bend them into U shape according to 7.5.3 at room temperature, immerse them in salt water at a temperature of 205℃ (the concentration of salt water is: 1g of "chemically pure" NaCl per liter of tap water), with both ends of the conduit exposed to the water surface for about 100mm each. Pour the salt water into the conduit. During the calculation, try to make the inside and outside of the tube consistent. The test device is shown in Figure 11. After 24 hours, add a voltage of 2000V with a basic sine waveform of 50Hz between the two electrodes for 15 minutes. The voltage applied at the beginning is not more than half of the specified voltage. After 5s, it increases to the specified value. After reaching the specified time, it slowly decreases to ). During this period, observe whether the test companion has breakdown and flashover. Glow discharge that does not reduce the voltage can be ignored. GB/T 14823.2—93
The transformer used in the test should be designed so that after the output voltage is adjusted to the appropriate test voltage, when the output terminal is short-circuited, the output short-circuit current is not less than 200mA. When the output current is less than 100mA, the overload current relay should not operate, and the measurement error of the test voltage is not greater than ±3%.
Next, a 15mm long metal conductive film is put on one end of the sample and then placed in a salt water solution with a temperature of 60±2℃, such as the above concentration. Then, the electrodes are placed in their original positions and the circuit is connected according to Figure 12. After 2h, a 500V DC voltage is applied between the two electrodes to measure the insulation resistance of the sample.
The conductive layer should also be connected to the power supply, but not included in the measuring circuit. The reading is taken 1min after the voltage is applied. 7.8.2 For samples with an outer diameter greater than 25mm (specimen length 1.1m), one end is covered with a rubber Tighten the plug (or similar object with good insulation), and then insert it obliquely into the salt water of the above concentration (one end of the sample is about 100mm above the water surface), and the end of the sample is 30mm away from the container wall (the sample part should be padded with insulation). Conduct electrical insulation strength test and measure insulation resistance. The method and requirements are the same as those in 7.8.1. The electrical connection is shown in Figures 11 and 12.
Test voltage (AC 2kV,
Figure 11 Layout of withstand voltage strength test
Shangcheng test electrician (DC 500V)
IUMA DC ammeter
Figure 12 Layout of insulation resistance test
8 Inspection rules
8.1 Factory inspection
Formula:
8.1.1 All conduits delivered shall be inspected according to the factory inspection items. The items, requirements and methods of factory inspection are shown in Table 12.
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