GB/T 14823.4-1993 Special requirements for conduits for electrical installations--Bendable self-healing insulating material conduits
Some standard content:
National Standard of the People's Republic of China
Conduits for electrical installations
Special requirements
Pliable self-recovering conduits of insulating matcriais for electrical installations CB/T14823.4—93
This standard adopts IEC 61424 (1985) "Technical requirements for conduits for electrical installations Part 2: Special requirements for conduits - flexible self-recovering conduits of insulating matcriais for electrical installations". 1 Subject content and scope of application
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of flexible self-recovering conduits of insulating matcriais for electrical installations (hereinafter referred to as conduits). This standard applies to flexible self-recovering flat conduits and corrugated conduits of insulating matcriais for electrical installations, which are used to protect conductors and cables in the gas installation of 1(0)V and below lines, and whose cross-sectional area is shaped. 2 Reference standards
CB/T13381.1 General requirements for conduits for electrical installationsGB5169.1 Glossary of terms for fire hazard tests for electrical and electronic productsGB 2828 Count sampling procedures and sampling tables for batch inspection (applicable to continuous batch collection)GB2829 Count sampling procedures and sampling tables for periodic inspection (applicable to inspection of production process stability)3 Glossary
3.1 Burn (comhustion)
The oxidation exothermic reaction of a substance, accompanied by the generation of flames, burning and (or) smoke. 3.2 Flame
The gas phase combustion area with light.
3.3 Glow
The simultaneous generation of heat and light by heating of solid materials without combustion or other chemical reactions. 4 Classification and catheter marking
4.1 Classification
4.1.1 Classification by mechanical properties
: catheters that can withstand very small mechanical forces (referred to as "ultra-light" catheters) b. catheters that can withstand small mechanical stresses (referred to as "light" catheters): c. catheters that can withstand medium mechanical stresses (referred to as "medium-duty catheters"). 4.1.2 Temperature classification according to Table 1:
Approved by the State Administration of Technical Supervision on December 30, 1993 and implemented on October 1, 1994
Temperature classification
+90/—25
GB/T 14823.4—93
Usually the temperature shall not be lower than
During storage and transportation
During use and installation
Note, 1) This type of conduit will encounter a short-term temperature of about 10 90°C when used in precast concrete. 4.1.3 Classification by conduit flame resistance;
Flame-resistant conduit:
Non-flame-resistant conduit.
4.2 Conduit marking
4.2.1 Each conduit shall be marked with:
Manufacturer name, trademark or other identification symbol: model, outer diameter;
Individual performance marking in accordance with 1 in Appendix A;
Long-term use temperature
15～+60
15～+60
—10~+60
—5~+60
5～+601
15～+601
In addition, it should also be marked with additional performance marks in accordance with A2 in Appendix A. d.
The first mark is about 50mm from the end of the conduit, and the conduit should be re-marked every 1~~3m thereafter. 4.2.2
4.2.3 The order of arrangement of the marks is as follows;BM
Outer diameter sizewww.bzxz.net
Shanghai×X × Factory
Production) name (or trademark)
290/3200001
Performance number
The entire mark indicates the following:
BM type produced by Shanghai XXX Factory, with an outer diameter of 25mm, with the characteristics of self-recovery, small mechanical stress, temperature grade of +90℃, can be used as additional insulation, and is magnetic-resistant insulating material conduit. The meaning of the performance numbers is shown in Appendix A.
4.2.4 The marking should be durable, easy to identify and clear. 4.2.5 Marking can be done by molding, printing, printing adhesive labels, watermark transplantation, etc. Note: Wave effect tube, except for the In addition to marking, other methods of marking are allowed, but the marking should comply with the requirements of Article 4. 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 in the "Conduit outer diameter size" and "Outer diameter tolerance" items in Table 2 (see Figure 1). 5.1.2 The minimum inner diameter of the conduit shall comply with the corresponding provisions in the "Minimum inner diameter" item in Table 2 (see Figure 1). Conduit outer diameter size
Outer diameter tolerance
Minimum inner diameter d
Complete conduit
Length of coiling when running + m
GB/T 14823.4--93
limbs
Figure 1 Minimum inner diameter of flat guide and bellows
50~100
5.1.3 The minimum outer diameter of the guide tube shall comply with the corresponding provisions in item \d\ of Table 3 (see Figure 2). Slightly Xie Guo
Material: polished steel. du manufacturing public welfare. 01mm. Allowable grinding amount, +0.01mm.
Figure 2 Gauge for checking the minimum outer diameter of the conduit
Gauge for the outer diameter of the conduit
5.1.4 The minimum inner diameter of the conduit after bending and folding should allow the gauge that meets the corresponding size of "D\" in Figure 3 and Table 4 to pass. 63
Conduit outer diameter size
GB/T14823.4-93
Making material, solid, polished steel; the four orange edges are slightly rounded. F0.05mm
Manufacturing tolerance is:
Axial dimension tolerance: 0.2mm
Allowable wear: + 0.01m1,
Figure 3 Gauge for checking the minimum inner diameter of the conduit under bending and folding conditions"Table 4
5.1.5In addition to the size specifications of this standard, the conduit size and its manufacturing length can be agreed upon by the supply and demand parties. Note: When there is a special standard for the size of the conduit, that standard should be adopted. 50
5.2 Appearance, structure
5.2.1 The inner and outer walls (or corrugations) of the conduit should be smooth, without obvious defects such as bubbles, cracks and uneven color; the inner and outer surfaces should have no ridges (or ridges beyond the corrugations) and similar defects; the edge of the pipe mouth should be flat and not damage the insulation layer of the wire or cable. 5.2.2 The wall thickness of the conduit should be uniform. After the wall thickness uniformity test in 7.4.3, the wall uniformity should conform to the following formula: M,—m|≤0.1M F 0.1mm(i -1, 2.3...12).. Where: M—per -thickness measured value, a total of 12: M·—the average value of 12 measured values,
Note: The wall thickness of the corrugated pipe should be measured by its material thickness 6 Technical Requirements
6.1 Mechanical Properties
. (1)
6.1.1 Compression Resistance
After the conduit is subjected to the bed force test in 7.5.1, the difference between its outer diameter and the outer diameter after compression shall not be greater than 10% of the original outer diameter, and there shall be no cracks visible to the naked eye.
6.1.2 Impact resistance
After the 12 conduits are subjected to the impact test in 7.5.2, at least 9 of the conduits shall have no visible cracks on their surfaces. 6.1.3 Bending resistance
GB/T 14823.4—93
After the conduits are subjected to the bending test in 7.5.3, no visible cracks shall appear, and the conduits shall be able to pass the gauges with the corresponding size in D of Figure 3 and Table 4 under the action of their own weight without any initial velocity. 6.1.4 Bending resistance
.After the conduits are subjected to the bending test in 7.3.4, no visible cracks shall appear. And the conduits shall be able to pass the gauges with the corresponding size in D of Figure 3 and Table 4 under the action of their own weight without any initial velocity. 6.2 Heat resistance
After the heat resistance test in 7.6, the conduit should be able to allow the gauge of the corresponding size in Figure 3 and item D in Table 4 to pass under its own gravity without any initial velocity.
6. 3 Flame resistance
After the heat resistance test in 7.7, the conduit should meet the following requirements: a. The conduit does not burn;
b. The conduit burns with flames, but all flames and heat can be extinguished automatically within 30 seconds after the fire source leaves; and the silk paper underneath does not catch fire and the pine board is not burnt.
Previous: Net paper is a soft and strong lightweight packaging paper with a specific gravity in the range of 12 to 30 g/m. 6.4 Electrical insulation
After the conduit is subjected to 7.8 After the electrical insulation test, there is no breakdown or flashover phenomenon; its insulation resistance is not less than 100M. 7 Test method
7.1 General requirements
7.1.1 The conduit should be tested within 10 days (including the 10th day) after manufacture. 7.1.2 Unless otherwise specified, the test is usually carried out under room source; in case of dispute, the test is carried out in an environment of 25±5℃. 7.1.3 Unless otherwise specified, each type of test should be carried out on three specimens. Three guide arms are randomly selected, and specimens for various tests are cut from these pipes. Each conduit provides a specimen for each test. 7.2 Marking inspection
Use a piece of cloth fully soaked in water to wipe the mark at a speed of 2 times/(the forward and backward movements of the hand are counted as 1 time each) at a uniform speed for 15§, and then use a piece of cloth fully soaked in gasoline to wipe at the same speed for 15s, and then check according to the requirements of Article 4.2. 7.3 Dimensional inspection
7.3.1 The outer diameter of the conduit is measured with a vernier caliper with a graduation value of 0.02mm. Note: The outer diameter of the corrugated pipe is the distance between the two peaks of the same surface and the same cross section. 7.3.2 The shape and detailed dimensions of the gauge for measuring the minimum outer diameter of the conduit are shown in Figure 2 and Table 3. When measuring the conduit of the corresponding size, the conduit that cannot pass the gauge without any force is qualified. 7.3.3 The minimum inner diameter of the conduit can be measured with a vernier caliper with a graduation value of 0.02mm. 7.3.4 The shape and detailed dimensions of the gauge for measuring the minimum inner diameter of the conduit after bending or folding are shown in Figure 3 and Table 4. When measuring the conduit of the corresponding size, the conduit that can pass the gauge without any external force and initial velocity is qualified. 7.4 Appearance and structure inspection
7.4.1 The appearance quality and structure of the conduit shall be inspected by measuring and using measuring tools with appropriate accuracy. 7.4.2 If necessary, the sample can be cut or longitudinally split for inspection. 7.4.3 Inspection of wall thickness uniformity: Generally, daily measurement is sufficient; if in doubt, three samples can be taken from different sections of the same conduit (cut along the plane of the vertical axis), and then measured at four positions on the circumference of each cut as equally spaced as possible, where the position is the thinnest part of the pipe wall. Use a wall thickness micrometer or a suitable measuring tool to measure. The measured values are 12 in total, and their average value M is calculated. Check according to formula (1). 7.5 Mechanical properties inspection
7.5. 1 Pressure test
GB/T14823.4-93
Take three samples with a length of 200 mm, first measure their initial outer diameter D, place them horizontally at room temperature, and then place them on a steel support after 10 hours: and place a square block at the center of the sample, as shown in Figure 4. Apply a slowly increasing force to the steel block. The initial outer diameter of the specimen is compressed by -30% within 30 seconds. This force shall not be less than the value shown in Table 5. Force
Sensitivity block
Specimen!
Conduit force type
Ultralight
Support pressure
Figure 4 Arrangement of pressure test
Applied pressure
After 30 seconds, remove this force and the square steel block. 15 minutes later, measure the outer diameter D. of the specimen where it is flattened. The difference between L and D. should not be greater than 10% of D., and check whether the specimen has cracks.
7.5.2 Impact test
Take 12 specimens with a length of 200 mm, place them at a temperature of 60±2°C for 240 h and then put them in a freezer. The freezer temperature is shown in Table 6:
Tube type (by temperature)
5 and +90 type
-15 type
—25 and 90/25 type
Freezer temperature
—5±1
- 15+1
-45±1
When the specimens reach the temperature in the box or after 2 h (whichever is longer), take out the specimens one by one and place them on the steel base as shown in Figure 5, and make a hammer drop to impact them (from taking out the specimens to the hammer dropping and impacting, it should be controlled within 10 s). The impact height and hammer weight are shown in Table 7. Force type of conduit
Ultralight
GB/T 14823.4—93
Spacer
(100g)
Periodic support<10 kg）
Gum gasket (thickness 40m)
Light production test
AB ester
Figure 5 Impact test arrangement
Hammer weight
After the test, at least 9 specimens should have no visible cracks on the surface to be qualified. 7.5.3 Bending test
Take 6 specimens for the test. The length of each specimen is at least: 30 times the outer diameter for flat conduits;
12 times the outer diameter for corrugated pipes.
French height
Falling height
100±1
Three of the samples were tested at room temperature; the other three samples were tested after low temperature treatment. Low temperature treatment and its temperature control are shown in Table 8:
Catheter type (by temperature)
-5, +90, -15 type
Other types
Freezer temperature,
--5±1
—15+1
Residence time in the freezer
The sample reaches the temperature in the freezer or more than 2h, whichever is longer
During the test, take out the samples one by one and clamp them vertically on the bending device with the corresponding dimensions in Figure 6 and Table 9, and bend the samples left and right by hand by 90°, and return to the same vertical position each time for the next bend. There should be a rest time of 1 minute between each bending action. Bend 4 times, and stay in place for 5 minutes after the last bend, and make the straight part of the test sample form a 45° angle with the vertical position: one end of the sample faces up and the other end faces down, and put it into a gauge that meets the corresponding size of item D in Figure 3 and Table 4, observe its passing, and check whether the sample has cracks. Sample
Conduit sliding
Figure 6 Bend test layout
Bending radius
7.5.4 Bending test
Conduit outer diameter size
Flat conduit
Corrugated pipe
Test with 3 samples. The bending device should meet the requirements of the corresponding size in Figure 6 and Table 9. The length of the sample should be at least: 30 times the outer diameter for flat conduit; 12 times the outer diameter for corrugated pipe.
Bend the sample at room temperature with a bending device, bend it to one side for about 90° and then return to the vertical position, then bend it to the opposite direction for about 90°, that is, fix the sample on the bracket shown in Figure 7, and put them together in an oven at a temperature of 60±2℃. 24h shop Place the bracket so that the straight part of the sample is at an angle of 45° to the vertical position, let the sample end up and the other end face down, put in a gauge that meets the corresponding scale of the ID item in Figure 3 and Table 4, and observe its passing. Then check whether the catheter has cracks. 7.6 Heat resistance test
GB/T14823.4—-93
Testing properties
Figure 7 Bending test arrangement
Put three 100mm long samples together with the test device (as shown in Figure 8) in the oven, and the overflow in the oven is shown in Table 10. Figure 8 Heat test arrangement
Type of conduit (connection temperature)
+90 type
Other types
Oven temperature
After 4 hours, a steel bar with an outer diameter of 6t1I is pressed in the middle of the sample (the steel bar is perpendicular to the axis of the sample) and a weight as shown in Table 7 is placed on the steel bar. After another 21 hours, the sample is allowed to cool to room temperature while maintaining the pressure, and then the weight and steel bar are removed; the sample is placed vertically and a gauge corresponding to the size of item D in Figure 3 and Table 4 is used, and it is inspected according to the requirements of Article 6.2. 7.7 Flame retardant test
GB/T14823.4--93
Flammable conduits should be subjected to this test. The entire test device is shown in Figure 9. This test is carried out in still air using 3 specimens of length (675 + 25) mm. The flame-spraying device is a Bunsen burner with a nozzle inner diameter of 9-10 mm. The flame is produced by propane gas, the gas volume of which should be such that the flame has a prescribed diameter. The energy produced by the Bunsen burner is 900t30W.
The Bunsen burner is placed in a vertical position and the flame is adjusted to a total length of 100 mm and a blue flame core length of 50 mm. The Bunsen burner is then tilted so that its axis is at an angle of 45° to the vertical and the test is then carried out. The time for the specimen to be burned by the flame is shown in Table 11. The package is made of a layer of pine board with a thickness of about 10m. Figure 9 Flame retardant test arrangement Washing rack Note: When the outer diameter of the conduit is 25mm or less, the diameter of the steel side is 6+0:1mm. When the outer diameter of the conduit is greater than 25mm, the diameter of the steel rod is 1610.1mm. The thickness of the conduit material is 0.5<8≤1.0
1.0<8≤1.5
2. 0<≤2.5
2.5≤3. 0
3.5<8≤4. 0
4.0≤8≤4.5
5.0<≤5. 5
5.5<≤6. 0
GB/T 14823. 4---93
Burning time on flame
After burning for the specified time, remove the Bunsen burner. During the whole process, observe whether the burning condition of the sample meets the requirements of Article 6.3. 7.8 Electrical insulation test
Bend 3 samples with a length of not less than 1.2m into a U shape (the radius of curvature is 6 times the outer diameter) and immerse them in salt water at a temperature of 20±5℃. The concentration of salt water is: 1g of The purity of the NaCl is "chemically pure", and the two ends of the sample are exposed to the water surface for about 100mm.
Pour the salt water into the sample so that the horizontal planes inside and outside the sample are almost the same, and immerse the two electrodes in the salt water inside and outside the sample respectively, as shown in Figure 10.
After 24 hours, apply a 2000V voltage with a basic sine waveform of 50Hz between the two electrodes for 15 minutes. During this period, observe whether there is any breakdown or flashover.
The high-voltage transformer used in the test should be designed as follows: after adjusting the output voltage to the appropriate test voltage, when the output terminal is short-circuited, its output short-circuit current should not be less than 200mA. When the output current is less than 100mA, the overload current continues to The electrical appliance should not operate, and the measurement error of the test voltage should not exceed ±3%. During the test, the starting voltage shall not exceed half of the specified value of the test voltage, and then quickly rise to the specified value. After reaching the specified time, it will slowly drop to zero.
Next, put a metal conductive film on one end of the sample, connect the circuit according to Figure 11, and place these samples on salt water with a temperature of 60±2°C and a concentration as mentioned above; then place the electrodes on the original bone. After 2h, apply a DC voltage of 500V between the two electrodes. The metal conductive film should also be connected to the power supply, but not included in the measurement circuit. Measure the insulation resistance of the sample after pressurization for 1min. 8 Inspection regulations
8.1 Factory inspection
GB/T 14823.493
Test voltage (AC 2kV)
Withstand voltage test
1Test voltage (DC 500V)
1A Commercial electrician
Conductive layer
Figure 11 Insulation resistance test
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. 8. 1. 1
Inspection Items
Marking Inspection
Dimension Inspection
Irrigation and Control Inspection
Chapter and Article of this Standard
Technical Requirements
Test Method
Classification of Nonconformity
8.1.2 Inspection shall be conducted by random sampling from each batch of delivered goods. Sampling inspection and evaluation shall be conducted in accordance with the relevant provisions of GB2828, as shown in Table 13. For details, see Appendix B.
Sampling Scheme Strictness
Normal Inspection
Inspection Level
General Inspection Level
Sampling Method Type
Secondary Sampling
Qualified Quality Level AQL
Class B Nonconformity: 4
Class C Nonconformity: 6. 5
Each sample is considered qualified only when it meets the qualified quality level of Class B and Class C non-conformities. The qualification of each batch is determined according to the attached
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