NB/T 10310-2019Electric heating strip (wire) of auxiliary heating for compressor (English PDF)

3.1 Electric heating strip (wire)

The electric heating element is made of high-resistance alloy wire wound on glass fiber treated with silicone resin surface, and covered with silicone rubber as an insulating and thermally conductive layer.

Note: Electric heating belt (wire) includes electric heating belt, electric heating wire, and metal shell electric heating wire.

3.1.1 Electric heating strip

It is made of high-resistance alloy wire wound on glass fiber with silicone resin surface treatment, with silicone rubber as an insulating and heat-conducting layer, and the end is heat-resistant A ribbon-shaped electric heating element connected by a silicon rubber wire, and both ends are fixed by a spring.

3.1.2 Electric heating wire

It is made of high-resistance alloy wire wound on glass fiber with silicone resin surface treatment, and outsourcing silicone rubber as an insulating and thermal conductive layer The outer layer is covered with a metal mesh belt woven with stainless steel wire or tinned copper wire, and the ends are connected with heat-resistant silicon rubber wires. Fixed by spring.

3.1.3 Electric heating wire with metal housing

It is made of high-resistance alloy wire wound on glass fiber with silicone resin surface treatment, with silicone rubber as an insulating and heat-conducting layer, and the end is heat-resistant Silicone rubber wire is connected to the terminal and molded, and then covered with a metal shell for heat conduction and fixed electric heating elements outside the insulating heat conduction layer. The quick lock hoop is fixed.

3.2 Heating-area

The area on the surface of the electric heating belt (line) that generates heat as required by the drawing.

3.3 Normal operation

When the electric heating belt (wire) is connected to the power source, it will work according to normal use (conditions).

3.4 Working temperature

The average temperature of the heating surface of the electric heating belt (line) under the rated input power and normal working condition.

3.5 Simulation condition

Under the state of each clause of this standard, some measures shall be taken to make the average temperature and working temperature of the heating surface of the electric heating belt (line) basically Compliant working conditions.

3.6 Operation life

The cumulative working time of the electric heating belt (line) working under the specified conditions to failure.

4.1 Model naming

Manufacturers can choose model naming rules according to actual needs.

Please refer to Appendix A for the model naming rules of an electric heating belt (line).

4.2 Typical structure

4.2.1 Figure 1 shows the appearance and structure of the electric heating belt.

4.2.2 The outline structure of the electric heating wire is shown in Figure 2.

4.2.3 The outline structure of the metal shell electric heating wire is shown in Figure 3.

5.1 Basic requirements

5.1.1 The electric heating belt (wire) should meet the requirements of this standard and be manufactured in accordance with the drawings and technical documents approved by the prescribed procedures.

5.1.2 The electric heating belt (line) should work normally under the following conditions.

a) Ambient temperature -45 °C~+140 °C;

b) The relative humidity of the surrounding air is not more than 90% (when the temperature is 20 °C ± 2 °C);

c) Working power supply. not higher than 480 VAC or 480 VDC;

d) Power frequency. 50 Hz or 60 Hz.

5.2 Appearance

The surface of the electric heating belt (wire) and the lead wire should be smooth, uniform in color, without obvious scars, pores and other defects, and the joints of the belt body should be bonded without peeling There is no obvious mechanical scars and burrs on the metal shell.

5.3 Structure size

The electric heating tape (line) should meet the requirements of the drawings and technical documents, and the dimensions without tolerances shall be assessed according to the V level of GB/T 1804.

5.4 Mechanical properties

5.4.1 The riveting of the tension spring buckle and the connection between the wire and the electric heating tape (wire) should be firm and reliable, and should withstand a tension of 50 N for 10 s. Detachment and displacement phenomenon.

5.4.2 The connection between the metal shell electric heating wire shell and the lock hoop should be able to withstand a 500 N tension for 10 s without detachment and displacement.

5.4.3 The two rubber sleeves of the electric heating belt (wire) shall bear a tensile force of 50 N, and there shall be no detachment, displacement or internal open circuit after 30 s. Elephant.

5.5 Rated power deviation

Under normal working conditions, the deviation of the input power of the electric heating belt (line) from the rated input power should not exceed ±7%.

5.5 Requirements

During the factory inspection, it is allowed to measure the cold resistance value of the electric heating belt (line) and convert the power according to the following formula (1).

5.6 Temperature deviation and maximum working temperature

The surface working temperature of the electric heating belt (wire) should be uniform, the temperature deviation should not be greater than ±10%, and the highest surface working temperature should not be greater than 140 °C.

5.7 Insulation resistance

The insulation resistance between the live part of the electric heating belt (line) and the shell (water) should not be less than 100 Mohm.

5.8 Electric strength

Between the live part of the electric heating belt (line) and the shell (water) should be able to withstand the corresponding test voltage (when the rated voltage is not greater than 440 V, the test The test voltage is 1 800 V; when the rated voltage is greater than 440 V and not greater than 480 V, the test voltage is 1 890 V;) 1 min, 50 Hz or 60 Hz Basic sine wave withstand voltage test, there should be no breakdown flashover during the test.

5.9 Leakage current

The leakage current of the electric heating belt (line) at the working temperature is <=0.2 mA.

5.10 Flexibility

The electric heating tape (wire) should be intact after the flexure test, and the surface of the belt body should be smooth and flat, without wrinkles or cracks (except for the metal shell electric heating wire) outer).

5.11 Sealing performance

The electric heating tape (wire) shall meet the requirements of 5.7-5.9 after the sealing performance test.

5.12 High temperature resistance

After the high temperature test, the electric heating tape (wire) shall meet the requirements of 5.7 to 5.9, and the surface shall not be deformed, damaged, cracked, etc.

5.13 Low temperature resistance

After the low temperature test, the electric heating tape (wire) shall meet the requirements of 5.7 to 5.9, and the surface shall not be deformed, damaged, cracked, etc.

5.14 Resistance to constant heat and humidity

After the electric heating belt (wire) is subjected to the constant damp heat test, it shall meet the requirements of 5.7~5.9, and the surface shall not be deformed, damaged, cracked, etc. phenomenon.

5.15 Resistance to thermal shock

After the electric heating tape (wire) undergoes the thermal shock test, it should meet the requirements of 5.7~5.9, and the surface must not be deformed, damaged, cracked, etc. phenomenon.

5.16 Overload capacity

The electric heating belt (line) should be able to withstand a working cycle overload test of 1.33 times the rated power for 5 cycles, without bending, rupture, and other effects. Energy phenomenon.

5.17 Flame retardant

The insulating material should meet the requirements of GB/T 5169.5. After the test sample is subjected to a 30 s needle flame test, it should meet one of the following conditions.

a) The test sample does not produce flame or burning phenomenon;

b) After the needle flame is removed, the duration of the flame or burning of the test sample, surrounding parts and bottom layer should be less than 30 s, and when used When packaging silk paper and white pine boards, the packaging silk paper will not burn or the white pine boards will not be charred.

5.18 Working life

The working life of the electric heating belt (wire) should not be less than 3 000 h.

5.19 Salt spray test

After the 48-hour test, there was no rust, oxidation, or coating peeling on the surface of the metal parts.

5.19 Requirements

5.20 Requirements for the restriction of hazardous substances

The content of harmful substances in heating belts (wires) used in electronic and electrical products should meet the requirements of GB/T 26572.

6.1 General requirements for testing

6.1.1 The test should be conducted at a surrounding environment temperature of (20±2) °C, no wind, no strong radiation, and relative humidity not greater than 90%.

6.1.2 The deviation of the power supply voltage shall not exceed ±1%.

6.1.3 The components are installed in electrical appliances or under simulated conditions.

6.1.4 The accuracy of the rated power test instrument is not less than 0.5, and the accuracy of other instruments is not less than 1.0.

6.2 Appearance

The visual inspection method should meet the requirements of 5.2.

6.3 Structural dimensions

Use steel ruler, tape measure or vernier caliper to measure, the size should meet the requirements of 5.3

6.4 Mechanical performance test

Measured with a dynamometer, the stretching speed is 5 mm/s. After reaching the specified value, it is stable for the specified time and should meet the requirements of 5.4.

6.5 Rated power measurement

Make the electric heating belt (wire) work under the rated voltage and normal working condition. When the input power is stable, measure the input power and it should meet

6.6 Temperature deviation measurement

Under the rated voltage, after the test piece is energized for 20 minutes to reach the rated input power, use a semiconductor point thermometer or other temperature that meets the test requirements In the electric heating belt (line) along the length of the heating zone 50 mm away from both ends, no less than 5 points are evenly distributed to measure the surface working temperature, Calculate the upper and lower temperature deviation values, and the calculation formulas are formula (2) ~ formula (4) as follows. […]

6.7 Insulation resistance test

Immerse the electric heating tape (wire) in tap water, leave both ends of the lead wire (10±2) cm away from the water surface, and measure the charged part and the outside with a megger.

The insulation resistance between the shells (water) should meet the requirements of 5.7.

6.8 Electric strength test

Immerse the electric heating tape (wire) in tap water, leave both ends of the lead wire (10±2) cm away from the water surface, and measure the charged part with a withstand voltage tester The electrical strength between the enclosure (water) and the enclosure (water), when the rated voltage is not greater than 440 V, the test voltage is 1 800 V; the rated voltage is greater than 440 V and does not When greater than 480 V, the test voltage is 1 890 V, the setting current of the test equipment is 5 mA, and the test result should meet the requirements of 5.8.

6.9 Leakage current measurement

Immerse the electric heating tape (wire) in tap water, leave both ends of the lead wire (10±2) cm away from the water surface, pass 1.1 times the rated voltage, and wait for output After the input power is stable, measure the leakage current between the live part and the enclosure (water), which should meet the requirements of 5.9.

6.10 Flexural test

The test is carried out by manual method. The belt body part of the electric heating belt (wire) is bent 20 times at 180°, and the bending speed is once per second.

The radius is 30 mm and should meet the requirements of 5.10 after the test.

6.11 Sealing performance test

Immerse the electric heating tape (wire) in tap water, leave both ends of the lead wire (10±2) cm away from the water surface, and the immersion time for 24 hours, test its performance It should meet the requirements of 5.11.

6.12 High temperature resistance test

The body of the electric heating belt (wire) is placed in an environment with a temperature of (200±5) °C for 168 hours, and then restored at room temperature for 2 hours, which shall comply with 5.12 Requirements.

6.13 Low temperature resistance test

The heating belt (line) body is placed in an environment with a temperature of (-45±5)°C for 168h, and then restored at room temperature for 2h, which shall comply with 5.13 Requirements.

6.14 Constant humidity and heat resistance test

The heating belt (line) body is placed in an environment with a temperature of (60±5) °C and a relative humidity of 90% to 95% for 168 hours, and then at room temperature After 2 hours of recovery, it shall meet the requirements of 5.14.

6.15 Thermal shock test

The sample is placed in a constant temperature box at (-45±5)°C for 1 h, and the sample is taken out and placed in a room temperature environment for 2 min~3min, then placed at (150±3)°C In the incubator for 1 hour, take it out and place it in a room temperature environment for 2 min to 3 min as a cycle, and continue for 30 cycles. After the test is completed, Meet the requirements of 5.15.

6.16 Overload test

Adjust the power supply voltage, the electric heating belt (line) is at 1.33 times the rated power condition, so that the surface temperature reaches a constant level, and then the power supply is turned off and blowing Air cooling reduces the temperature to (43 ± 10) °C and then conducts electric heating. After 5 cycles, the inspection shall meet the requirements of 5.16.

6.17 Flame retardant test

After testing according to the method specified in GB/T 5169.5, it shall meet the requirements of 5.17.

6.18 Working life test

The electric heating belt (line) should meet the requirements of 5.18 after applying 1.15 times the rated voltage and continuously energizing for 3 000 h.

6.19 Salt spray test

Carry out in accordance with the provisions of GB/T 2423.17, the test time is 48 hours, and the test conditions. temperature (35±2) °C, continuous spraying of 5% NaCl solution Fog, the pH of the solution is between 6.5 and 7.2. After the test, use clean running water at a temperature not exceeding 35 °C to gently wash off the surface residue of the test sample.

Leave the salt deposits, then place the sample naturally for 1 h~2 h under ventilated conditions; observe the metal parts on the sample after the test, and it should meet

6.20 Detection of hazardous substance content

After testing according to the method specified in GB/T 26125, it should meet the requirements of 5.20.

7.1 Inspection classification

Inspection is divided into factory inspection and type inspection.

7.2 Factory inspection

7.2.1 All products proposed for delivery shall be tested in accordance with the specified delivery inspection items. Each product is inspected by the company's quality inspection department It can leave the factory only if it is qualified and has a product certificate or a conformity mark specified by the manufacturer on the product.

7.2.2 The factory inspection items, requirements and test methods are shown in Table 1.

7.3 Type inspection

7.3.1 Type inspection shall be carried out in one of the following situations.

--When the new product is tested and approved;

--When there are major changes in structure, materials, and processes that affect product performance;

- When production is stopped for more than one year and production is resumed;

-For continuous batch production of products, at least once a year;

--When the user unit or the quality supervision department deems it necessary.

7.3.2 The samples for type inspection shall be randomly selected from the products that have passed the factory inspection and packaged.

7.3.3 The products for type inspection are divided into two groups, each with three pieces.

The items, requirements and test methods of the first group of type inspection are shown in Table 2.

7.3.4 Products after type inspection shall not be delivered as finished products.

7.3.5 In the inspection items 1, 7-9, 11-17 in Table 2, as long as one item is unqualified, the type inspection shall be deemed unqualified.

7.3.6 In the other inspection items in Table 2, if more than one sample is unqualified, the type inspection shall be deemed unqualified; if there is only one If the sample is unqualified, a doubled number of samples can be drawn from the batch of products to repeat the test, and the repeated test samples should be qualified, as long as If one sample is unqualified, the type inspection shall be deemed unqualified.

7.4 Other

The ordering party has the right to check whether the product meets the requirements of this standard, and accept it according to the factory inspection items during delivery. If there is any doubt about the product quality, Have the right to request additional inspection items. If the inspection is qualified, it will be delivered together with the sample.

8.1 Product mark

8.1.1 There should be a scratch resistance mark on the electric heating belt (line), and the content of the mark should include.

a) Manufacturer's name or code or trademark;

b) Product model;

c) Factory year and month;

d) Rated voltage and rated power.

8.1.2 There should be a durable and obvious mark on the outside of the packing box. The content of the mark includes.

a) The name of the manufacturer;

b) Product name and model;

c) the number of components;

d) Net weight and gross weight;

e) Box size, length × width × height (mm);

f) Packing number;

g) "Handle with care", "sun protection", "rain protection" and "moisture protection" marks;

h) Year and month of delivery.

8.2 Packaging

8.2.1 The heating belt (line) should be packed in a packing box with suitable padding, and there should be a number of certificates, packing quantity, and instructions for use in the box.

8.2.2 If the manufacturer and the customer have an agreement, follow the packaging agreement.

8.3 Transportation

The heating belt (line) should be protected from shock, vibration and direct rain and snow during transportation.

8.4 Storage

The heating belt (line) should be stored in a warehouse that is ventilated and dry, without corrosive gas, and protected from rain and snow.