JB/T 7573-1994 General technical requirements for electrical products under plateau environmental conditions
Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T 7573-1994
General Technical Conditions for Electrical Products under Plateau Environmental Conditions, Issued on December 9, 1994
Ministry of Machinery Industry of the People's Republic of China
Implementation on June 1, 1995
Mechanical Industry Standard of the People's Republic of China
General Technical Conditions for Electrical Products under Plateau Environmental Conditions 1 Subject Content and Scope of Application
JB/T7573-1994
This standard specifies the altitude classification, climate and environmental parameters, the relationship between product performance and altitude, and the common requirements for various types of electrical products used in plateau areas under plateau environmental conditions (including indoor and outdoor). This standard applies to the following electrical products used at altitudes of less than 5000m: motors; power transmission and transformation equipment; low-voltage electrical appliances, low-voltage complete switchgear and electric control equipment; power semiconductor devices, power converters, etc. 2 Reference standards
GB311.1~311.6 Insulation coordination of high-voltage power transmission and transformation equipment High voltage test technology GB311.7
Insulation coordination of high-voltage power transmission and transformation equipment
Guidelines for use
GB1094
GB1497
GB2900
GB3797
GB3859
GB4720
GB6450
GB6915
GB7251
JB3140
3 Altitude classification of electrical products
Basic technical requirements for rotating electrical machines
Heating of AC high-voltage electrical appliances during long-term operation Power transformers
Basic standards for low-voltage electrical appliances
Electrical terminology
Electrical control equipment Part II: Electronic control equipment equipped with electronic devices Semiconductor power converter
Electrical control equipment Part I: Low-voltage electrical appliances Electronic control equipment Electrical and electronic products Natural environmental conditions Altitude and air pressure, water depth and water pressure Environmental conditions for application of electrical and electronic products Fixed use in places with climate protection Environmental conditions for application of electrical and electronic products Fixed use in places without climate protection Dry-type power transformers
Highland power capacitors
Low-voltage complete switchgear
High-voltage motors are used in high-altitude areas. The anti-electrical standard is in accordance with GB4797.2. The altitude classification is as follows: 1000, 2000, 3000, 4000, 5000m. Note: The altitude classification is applicable to the normal working conditions for the design and manufacture of electrical products for plateaus. The actual altitude of 0~1000m uses the 1000m level; the actual altitude of 1000~2000m uses the 2000m level; the actual altitude of 2000~3000m uses the 3000m level; the actual altitude of 3000~4000m uses the 4000m level; the actual altitude of 4000~5000m uses the 5000m level. 4. Climate and environmental parameters
The climate and environmental parameters for altitudes of 0~5000m are shown in Table 1. Note: When designing and manufacturing plateau electrical products, the climate and environmental parameters shall be selected according to the altitude classification determined in Chapter 3 of this standard. For general electrical products, the climate parameters can be selected according to the altitude classification determined in Chapter 3 of this standard; or the climate and environmental parameters can be determined by linear interpolation in the corresponding range according to the parameters in Table 1 based on the actual use altitude. Approved by the Ministry of Machinery Industry on December 9, 1994
Implemented on June 1, 1995
Air pressure
Air temperature
Relative humidity
Absolute humidity
Environmental parameters
Annual average
Highest daily average
Annual average
Maximum daily temperature difference/K
Wettest month Monthly average maximum
(Corresponding monthly average minimum Temperature/C)
Minimum average monthly temperature in the driest month
(corresponding monthly average maximum temperature/C)
Annual average, average
Annual average minimum
Maximum direct solar radiation/W/m
Maximum wind speed/m/s
Maximum 10min precipitation/mmbzxz.net
Maximum soil temperature at 1m depth/C
JB/T7573-1994
95, 90
The influence of plateau climate conditions on the performance of electrical products The plateau has relatively severe natural climate conditions, which are characterized by: a.
low air pressure or air density;
low air temperature and large temperature changes; low absolute air humidity;
high solar radiation illumination;
less precipitation and
more windy days per year;
low soil temperature and long freezing period
The influence of reduced air pressure or air density on the strength of insulating dielectric
Altitude/km
,-15,
-25,
-40,
15,25,30
95,90
25,30,35,40
15,30
The reduction of air pressure or air density causes the reduction of external insulation strength. Within the range of 5000m above sea level, for every increase of 1000m, that is, for every decrease of 7.7~10.5kPa in average air pressure, the external insulation strength decreases by 8%~13%. 5.1.2 The influence on the breakdown voltage of electrical clearance For the products with finalized design, since the electrical clearance is fixed, its breakdown voltage also decreases with the decrease of air pressure. In order to ensure that the product has sufficient breakdown resistance when used in plateau, the electrical clearance must be increased. The electrical clearance of electrical products for plateau use can be corrected according to Table 2. 2
Altitude of the place of use/m
Corresponding air pressure/kPa
Electrical clearance
Correction coefficient
Based on zero altitude
Based on 1000m altitude
Based on 2000m altitude
Influence on corona and discharge voltage:
JB/T7573-1994
High altitude and low air pressure reduce the partial discharge starting voltage of high-voltage motors, reduce the corona starting voltage, and cause serious corona corrosion. High altitude and low air pressure reduce the internal air pressure of power capacitors, resulting in a decrease in the partial discharge starting voltage. High altitude and low air pressure reduce the air pressure in the inner cavity of the arrester, resulting in a decrease in the power frequency discharge voltage. Impact on the arc extinguishing performance of switchgear
The decrease in air pressure or air density reduces the arc extinguishing performance of switchgear with air medium arc extinguishing, reduces the switching capacity and shortens the electrical life. The arcing time of DC arc is prolonged with the increase of altitude or the decrease of air pressure; a.
The arcing distance of DC and AC arcs increases with the increase of altitude or the decrease of air pressure. b.
5.1.5 Impact on the cooling effect of the medium, that is, the temperature rise of the product The decrease in air pressure or air density causes the decrease of the cooling effect of the air medium. For electrical products that use natural convection, forced ventilation or air radiator as the main heat dissipation method, the temperature rise increases due to the decrease in heat dissipation capacity. Within the range of 5000m above sea level, the temperature rise increases by 3%~10% for every increase of 1000m, that is, every decrease of 7.7~10.5kPa in the average air pressure. The rate of increase of temperature rise of stationary electrical appliances with increasing altitude is generally within 0.4K per 100m, but for high-heating electrical appliances, such as electric furnaces, resistors, welding machines, etc., the rate of increase of temperature rise with increasing altitude is more than 2K per 100m. b. The increase of temperature rise of power transformers with increasing altitude is related to the cooling method. Its increase rate per 100m is: oil-immersed self-cooling, 0.4% of the rated temperature rise; dry self-cooling, 0.5% of the rated temperature rise; oil-immersed forced air cooling, 0.6% of the rated temperature rise: dry forced air cooling, 1.0% of the rated temperature rise c. The rate of increase of motor temperature rise with altitude is 1% of the rated temperature rise per 100m. 5.1.6 Impact on product mechanical structure and sealing a. Cause changes in the physical and chemical properties of low-density, low-concentration, porous materials (such as electrical insulation materials, thermal insulation materials, etc.). The evaporation of lubricants and the volatilization of plasticizers in plastic products are accelerated: gases or liquids are easy to leak from sealed containers or the leakage rate increases; electrical products with sealing requirements have an indirect impact on electrical performance; causing changes in the pressure of pressure vessels, making pressure vessels prone to rupture. The impact of reduced air temperature and increased temperature changes (including daily temperature differences). 5.25
Compensation of plateau ambient air temperature for product moisture rise The average air temperature and the maximum air temperature both decrease with increasing altitude. The thermal aging life of electrical insulation materials is determined by the average air temperature. The reduction in plateau ambient air temperature can partially or completely compensate for the increased temperature rise of electrical products during operation caused by reduced air pressure. The compensation value of ambient air temperature is 0.5K/hm. 5.2.2. The impact of daily temperature difference or temperature change on product structure The daily temperature difference of air temperature in plateau is large. Large temperature changes make the product shell easy to deform and crack, and the sealing structure is easy to break. 5.3 The impact of reduced absolute humidity of air
5.3.1 The impact of absolute humidity on external insulation strength The average absolute humidity decreases with increasing altitude. When the absolute humidity decreases, the external insulation strength of electrical products decreases, so the humidity correction of power frequency discharge voltage and impulse flashover voltage should be considered. JB/T7573-1994
Humidity correction is based on the average absolute humidity at zero altitude: 11g/m3, and the specific correction is in accordance with the relevant provisions of GB311.2. 5.3.2 The impact of absolute humidity on motor commutation and carbon brush wear The reduction of absolute humidity increases the commutation spark of the commutator motor and increases the wear rate of the motor carbon brush. 5.4 Solar radiation illuminance, including the effect of increased ultraviolet radiation illuminance 5.4.1 Effect of increased plateau thermal radiation
The maximum solar radiation at an altitude of 5000m is 1.25 times the corresponding value at a low altitude. Thermal radiation heats objects. For outdoor electrical products, the increase in solar thermal radiation causes a large additional surface temperature rise, reduces the material properties of organic insulating materials, causes material deformation, and generates mechanical thermal stress.
5.4.2 Effect of increased plateau ultraviolet radiation The rate of increase of ultraviolet radiation illuminance with increasing altitude is much greater than the rate of increase of total solar radiation illuminance. At an altitude of 3000m, it has reached twice the corresponding value at a low altitude. Ultraviolet rays cause accelerated aging of organic insulating materials, making air easily ionized, resulting in reduced external insulation strength and corona inception voltage.
6 Basic technical requirements for various types of electrical products used in plateau areas 6.1 Motors
This provision includes motors defined in GB2900.25, especially rotating motors. 6.1.1 When the motor is used at an altitude of 1000m to 4000m, the correction of the temperature rise limit shall be in accordance with the provisions of GB755. When the altitude exceeds 4000m to 5000m, the compensation value of the required ambient temperature reduction for each increase of 100m shall still be converted to 1% of the temperature rise limit. 6.1.2 Motors with a voltage of more than 3kV shall be subjected to corona tests in accordance with the provisions of JB3140. 6.2 Power transmission and transformation equipment
This provision includes the power transmission and transformation equipment defined in GB2900.19, namely power transformers, mutual inductors, voltage regulators, reactors, switchgear, lightning arresters, power capacitors, insulators, insulating bushings, etc. 6.2.1 When the power transmission and transformation equipment is used at an altitude of 1000m to 4000m, the test voltage of its external insulation in a dry state shall be corrected for altitude in accordance with the provisions of GB311. When the altitude exceeds 4000m to 5000m, the correction method specified in GB311 shall be extrapolated. 6.2.2 For power transmission and transformation equipment used at an altitude of more than 1000m, the altitude correction factor K of the power frequency test voltage of its external insulation under rain conditions shall be calculated as follows:
Where: h——altitude, km.
rh=1 + (2. 5 h2. 5)-)
K=1+0.76[-1+
6.2.3 For power transmission and transformation equipment used at an altitude of more than 1000m, the altitude correction of its temperature rise shall be in accordance with the following standards and extrapolated to an altitude of 5000m:
switchgear, GB763;
power transformer, GB1094 and GB6450; b.
power capacitor, GB6915.
6.3 Low-voltage electrical appliances, low-voltage complete switchgear and electric control equipment This provision includes low-voltage electrical appliances defined in GB2900.18, including power distribution appliances and control appliances, as well as low-voltage electrical appliances and electric control equipment and low-voltage complete switchgear defined in GB4720 and GB7251. 6.3.1 Low-voltage electrical appliances, low-voltage complete switchgear and electric control equipment shall be corrected according to the following principles in accordance with the relevant provisions of GB1497, GB3797, GB4720 and GB7251, taking into account the reduction of air dielectric strength and cooling effect:
a. For the power frequency withstand test voltage value, increase by 1% for every 100m increase in the altitude of the use site; b. For the allowable temperature rise test value, reduce by 0.4K for every 100m increase in the altitude of the use site; 6.3.2 If there are no other provisions, low-voltage electrical appliances and complete equipment shall be corrected for altitude according to the altitude difference between the test site and the use site during type testing.
JB/T7573-1994
3Altitude correction factor for electrical clearance during impulse withstand voltage test, see Table 3.6.3.3
Altitude of test site/m
Corresponding air pressure/kPa
Altitude correction factor for impulse withstand voltage test
Power semiconductor devices, power converters
This provision includes power semiconductor devices and power converters defined in GB2900.32 and GB2900.33. The current capacity of power semiconductor devices and power converters shall be amended in accordance with Appendix B of GB3859.2. Additional notes:
This standard was proposed and managed by the Kunming Electric Science Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Kunming Electric Science Research Institute of the Ministry of Machinery Industry. The main drafter of this standard is Zhu Xuelu.
People's Republic of China
Mechanical Industry Standard
General Technical Conditions for Electrical Products under Plateau Environmental Conditions JB/T7573-1994
Published and issued by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Format 880×12301/16
Print Sheet X/X Number of Words XXX,XXX
Edition X, XX, XX, 19XX Printing X, XX, XX Price XXX.XX Yuan
Print Quantity 1-XXX
Number XX-XXX
Mechanical Industry Standard Service Network: http://www.JB.ac.cn66 /3. For power transmission and transformation equipment used at an altitude of more than 1000m, the altitude correction of temperature rise shall be in accordance with the following standards and extrapolated to an altitude of 5000m:
Switchgear, GB763;
Power transformer, GB1094 and GB6450; b.
Power capacitor, GB6915.
6.3 Low-voltage electrical appliances, low-voltage complete switchgear and electric control equipment This provision includes low-voltage electrical appliances defined in GB2900.18, including distribution electrical appliances, control electrical appliances, and low-voltage electrical appliances, electric control equipment and low-voltage complete switchgear defined in GB4720 and GB7251. 6.3.1 Low-voltage electrical apparatus, low-voltage complete switchgear and electric control equipment shall be corrected according to the following principles in accordance with the relevant provisions of GB1497, GB3797, GB4720 and GB7251, taking into account the reduction of air dielectric strength and cooling effect: a. For the power frequency withstand test voltage value, increase by 1% for every 100m increase in the altitude of the use location; b. For the allowable temperature rise test value, reduce by 0.4K for every 100m increase in the altitude of the use location; 6.3.2 Unless otherwise specified, for low-voltage electrical apparatus and complete equipment, altitude correction shall be made according to the altitude difference between the test location and the use location during type testing.
JB/T7573-1994
3Altitude correction factor for electrical clearance during impulse withstand voltage test, see Table 3.6.3.3
Altitude of test site/m
Corresponding air pressure/kPa
Altitude correction factor for impulse withstand voltage test
Power semiconductor devices, power converters
This provision includes power semiconductor devices and power converters defined in GB2900.32 and GB2900.33. The current capacity of power semiconductor devices and power converters shall be amended in accordance with Appendix B of GB3859.2. Additional notes:
This standard was proposed and managed by the Kunming Electric Science Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Kunming Electric Science Research Institute of the Ministry of Machinery Industry. The main drafter of this standard is Zhu Xuelu.
People's Republic of China
Mechanical Industry Standard
General Technical Conditions for Electrical Products under Plateau Environmental Conditions JB/T7573-1994
Published and issued by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Format 880×12301/16
Print Sheet X/X Number of Words XXX,XXX
Edition X, XX, XX, 19XX Printing X, XX, XX Price XXX.XX Yuan
Print Quantity 1-XXX
Number XX-XXX
Mechanical Industry Standard Service Network: http://www.JB.ac.cn66 /3. For power transmission and transformation equipment used at an altitude of more than 1000m, the altitude correction of temperature rise shall be in accordance with the following standards and extrapolated to an altitude of 5000m:
Switchgear, GB763;
Power transformer, GB1094 and GB6450; b.
Power capacitor, GB6915.
6.3 Low-voltage electrical appliances, low-voltage complete switchgear and electric control equipment This provision includes low-voltage electrical appliances defined in GB2900.18, including distribution electrical appliances, control electrical appliances, and low-voltage electrical appliances, electric control equipment and low-voltage complete switchgear defined in GB4720 and GB7251. 6.3.1 Low-voltage electrical apparatus, low-voltage complete switchgear and electric control equipment shall be corrected according to the following principles in accordance with the relevant provisions of GB1497, GB3797, GB4720 and GB7251, taking into account the reduction of air dielectric strength and cooling effect: a. For the power frequency withstand test voltage value, increase by 1% for every 100m increase in the altitude of the use location; b. For the allowable temperature rise test value, reduce by 0.4K for every 100m increase in the altitude of the use location; 6.3.2 Unless otherwise specified, for low-voltage electrical apparatus and complete equipment, altitude correction shall be made according to the altitude difference between the test location and the use location during type testing.
JB/T7573-1994
3Altitude correction factor for electrical clearance during impulse withstand voltage test, see Table 3.6.3.3
Altitude of test site/m
Corresponding air pressure/kPa
Altitude correction factor for impulse withstand voltage test
Power semiconductor devices, power converters
This provision includes power semiconductor devices and power converters defined in GB2900.32 and GB2900.33. The current capacity of power semiconductor devices and power converters shall be amended in accordance with Appendix B of GB3859.2. Additional notes:
This standard was proposed and managed by the Kunming Electric Science Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Kunming Electric Science Research Institute of the Ministry of Machinery Industry. The main drafter of this standard is Zhu Xuelu.
People's Republic of China
Mechanical Industry Standard
General Technical Conditions for Electrical Products under Plateau Environmental Conditions JB/T7573-1994
Published and issued by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Format 880×12301/16
Print Sheet X/X Number of Words XXX,XXX
Edition X, XX, XX, 19XX Printing X, XX, XX Price XXX.XX Yuan
Print Quantity 1-XXX
Number XX-XXX
Mechanical Industry Standard Service Network: http://www.JB.ac.cn66 /
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