Some standard content:
ICS31.060.70
Machinery Industry Standard of the People's Republic of China
JB/T7115—1993
Low-voltage local reactive compensation device
Low-voltage local capacitive
Compensation installaton
Published on October 8, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on January 1, 1994
Machinery Industry Standard of the People's Republic of China
Low-voltage local reactive compensation device
Low-voltage local capacitive
Compensation installaton
Subject content and scope of application
JB/T7115—1993
This standard specifies the scope of application, terminology, product classification, technical requirements, test methods, inspection rules and markings of low-voltage local reactive compensation devices.
This standard applies to reactive local compensation devices (hereinafter referred to as "devices") used in parallel with motors at the end of the power frequency AC power distribution system of 1kV and below to improve the power factor. 2
Cited standards
GB2681
GB2682
GB4208
Wire colors in complete electrical equipment
Colors of indicator lights and buttons in complete electrical equipmentClassification of enclosure protection levels
GB12747 Self-healing low-voltage shunt capacitorsJB7113
3 Terms
Low-voltage shunt capacitor device
3.1 Reactive local compensation
A compensation method in which a capacitive load is connected in parallel to the motor at the end of the power frequency AC power distribution system to improve the power factor of the distribution system. 3.2 Reactive local compensation device
A device for reactive local compensation with a shunt capacitor as the main body and equipped with protective devices, etc. 4 Product classification
4.1 Ambient air temperature category
The ambient air temperature range of the installation and operation area is -50℃~+55℃. Within this temperature range, it is divided into several temperature categories according to the ambient air temperature range that the device can adapt to. Each temperature category is represented by a lower limit temperature value and an upper limit temperature letter code separated by a slash.
The lower limit temperature is the lowest ambient air temperature at which the device can be put into operation, and its value is selected from +5℃, -5℃, -25℃, -40℃, and -50℃.
The upper limit temperature is the highest ambient air temperature at which the device can operate continuously. The relationship between the upper limit temperature letter code and the ambient air temperature is shown in Table 1.
Any combination of the lower limit temperature and the upper limit temperature can be selected as the temperature category of the device. The preferred temperature categories are: -5/A, -5/C, -25/C.
Approved by the Ministry of Machinery Industry on October 8, 1993
Implemented on January 1, 1994
Upper temperature code
JB/T7115-1993
Table 1 Ambient air temperature
Ambient air temperature
24h average maximum
Annual average maximum
Note: The special specifications negotiated by the manufacturer and the purchaser may be higher than the maximum temperature values listed in Table 1. The temperature category is expressed by the minimum and maximum temperature values, such as -5/70.
4.2 Basic parameters
4.2.1 Rated voltage
The preferred rated voltages are:
0.38, 0.66, 1kV.
4.2.2 Rated capacity
The rated capacity shall be selected from the following and the preferred number multiplied by 10 (unit: kvar). 3.0, 3.6, 4.8, 6.0, 7.5, 9.0, 10, 12, 15, 18, 24. 4.3 Category
The device is divided into indoor device and outdoor device. 5 Technical requirements
Usage requirements
5.1.1 Altitude
The altitude of the installation and operation area shall not exceed 2000m. Note: For devices with an altitude higher than the above specified value, the requirements shall be determined by the manufacturer and the purchaser through negotiation. 5.1.2 Ambient air temperature
Should meet the temperature category corresponding to the device. 5.1.3 Physical and chemical conditions
The installation site shall be free of harmful gases and vapors that damage insulation and corrode metals, and shall be free of conductive and explosive dust. The device shall not be exposed to strong electric and magnetic fields.
5.1.4 Overload
Should comply with the provisions of Articles 5.1.4, 5.1.5 and 5.1.6 of JB7113. 5.2 Structural requirements
5.2.1 Appearance
The outer surface of the device and the metal parts inside the device should have a good anti-corrosion layer, and the color should be uniform, without obvious flow marks, scratches, dents, dirt, anti-corrosion layer shedding and rust. The shell size, terminals and fixtures should comply with the product drawing requirements. The device shall not have exposed live parts.
The markings are clear and the data is correct.
5.2.2 Welding parts
JB/T7115—1993
The welding parts of the device should be firm, the welds should be flat, and there should be no welding penetration, cracks, undercuts, slag splashing, pores, slag inclusions, etc. 5.2.3 Wires and wiring
5.2.3.1 Insulated wires (or cables) should be able to safely flow through the maximum allowable current of the device and have sufficient mechanical strength. 5.2.3.2 When connecting the wires to the terminals of electrical components, measures should be taken to prevent electrical corrosion. All wiring points should be firm and in good contact. No wiring points are allowed in the middle of each wire.
The color of the wires should comply with the provisions of GB2681. 5.2.4 Operating devices
If the device has operating devices, they should move flexibly during operation without getting stuck or having excessive operating force or damage. 5.3 Performance requirements
5.3.1 Capacitance deviation
The difference between the total capacitance of the device and its rated capacitance: for one self-healing capacitor per phase, it should be within the range of 0~+15% of the rated capacitance; for one non-self-healing capacitor per phase, it should be within the range of -5%~+10% of the rated capacitance; for more than two capacitors per phase, it should be within the range of 0~+10% of the rated capacitance. The ratio of the maximum value to the minimum value of the capacitance between any two line terminals of the device shall not be greater than 1.08. 5.3.2 Insulation level
The connection terminals of the device and the casing shall be able to withstand the power frequency test voltage specified in Table 2. The type test lasts for 1 minute; the factory test lasts for 10 seconds.
For multi-phase devices, the phases shall also be able to withstand the test voltage specified in Table 2. During the test, no breakdown or flashover shall occur. Table 2
Test voltage
Rated voltage (root mean square value)
5.3.3 Temperature rise
The temperature rise on the surface of the device casing shall not exceed 15°C. Test voltage (RMS value)
The temperature at the connection point between the insulated wire and the electrical component shall not be higher than the long-term allowable operating temperature of the insulated wire, kv
The air temperature at the midpoint of the line connecting the hottest points of the two capacitor shells in the hottest area of the capacitor bank in the device or the midpoint of the vertical line connecting the hottest point of the capacitor shell and the device shell (if there is only one capacitor) shall not be higher than the maximum temperature of the corresponding temperature category of the capacitor plus 5°C.
The temperature rise of the device terminal shall not exceed the limit value specified in Table 3. 3
Bare brass
Copper (or brass) tinned
Terminal material
Copper (or brass) silver or nickel plated
Other metals
5.4 Safety requirements
5.4.1 Electrical clearance and creepage distance
JB/T7115—1993
Table 3 Temperature rise limits of terminal blocks
Temperature rise of terminal blocks
The electrical clearance and creepage distance between the electrical components in the device, between the exposed parts of the live conductors of different polarities and between them and the device casing shall not be less than the minimum values given in Table 4. Table 4
Rated voltage kV
0.3U≤0.6
Minimum electrical clearance and creepage distance
Electrical clearance
Note: ① When calculating the air path length, any air gap less than 1mm should be ignored. ② Creepage distance is the shortest distance along the surface of the insulating material between two conductive parts. 5.4.2 Residual voltage when put into operation
When the device is put into operation, the residual voltage on its terminals shall not exceed 10% of the rated voltage. 5.4.3 Discharge device
Creep distance
The discharge device must be able to ensure that the voltage on the terminal drops from √2U to 50V or below within 3 minutes after the device is disconnected from the power supply.
When the capacitor itself is equipped with a discharge device that meets the above requirements, the device does not need to be equipped with a separate discharge device. 5.4.4 Grounding
The metal casing of the device should have a reliable protective grounding terminal and an obvious and durable grounding mark. 5.4.5 Protection
5.4.5.1 Short-circuit protection
The device should be equipped with short-circuit protection. The short-circuit protection device should be able to effectively isolate short-circuit faults. When designing short-circuit protection, the impact of surge current when the device is put into use should be considered.
5.4.5.2 Other protection
Depending on the structure of the device, other protections can be set, such as overvoltage and overcurrent protection. If overvoltage or overcurrent protection is provided, when the steady-state overvoltage or overcurrent exceeds the provisions of Article 5.1.4, the protection device shall be able to cut off the capacitor and give an alarm.
5.4.6 Shell protection
The shell protection level of the device shall comply with the provisions of GB4208. Generally, it shall not be less than IP20 for indoor use and not less than IP44 for outdoor use. 5.5 Selection and installation of electrical components
5.5.1 Electrical components shall be selected from products that meet national standards and industry standards. 4
JB/T7115—1993
5.5.2 The rated voltage, rated current, service life, breaking capacity, short-circuit strength, etc. of the electrical components shall meet the requirements of the electrical parameters of the device.
5.5.3 If there is an indicator light, the color of the indicator light shall comply with the provisions of GB2682. 5.5.4 Electrical components shall be installed according to their instruction manuals, the components shall be firmly fixed, and the layout of the components shall be neat, correct, easy to install and wire.
5.5.5 The installation of heating electrical components should take into account the impact on adjacent electrical components. 6 Test methods
6.1 Test conditions
All tests of the device, unless otherwise specified, should be carried out in an ambient air temperature range of 5℃~35℃. If correction is required, the value at 20℃ shall prevail. The ambient air temperature during the test should be recorded. The temperature of the device should be consistent with the ambient air temperature. After the device is placed in a constant ambient air temperature for an appropriate period of time without power, the temperature of the device is considered to be consistent with the ambient air temperature. If there are no other regulations, the test voltage should be an AC voltage with a frequency of 45Hz~55Hz, and its waveform should be an approximate sine waveform (that is, the two half waves are basically the same, and the ratio of their peak value to the root mean square value is within the limit of √2±0.07, and the root mean square value of the harmonics is not greater than 5% of the root mean square value of the fundamental wave).
6.2 Appearance inspection
Inspect visually and with measuring tools according to the requirements of 5.2, 5.4.1 and 5.4.4, and check the markings. 6.3 Electrical component inspection
Electrical components shall be inspected according to the requirements of 5.5. Mainly check whether the electrical components in the device have certificates; whether the rated voltage and rated current of the electrical components meet the requirements; whether the electrical components are firmly installed, etc. 6.4 Capacitance inspection
The capacitance of the device shall be measured at a voltage of (0.9~1.1)U and a frequency of (0.8~1.2)fN, with a measurement accuracy of not less than 2%. Other methods that can ensure the measurement accuracy may also be used. 6.5 Withstand voltage test
When conducting the pole-to-shell voltage test, the terminals on the device that are insulated from the shell shall be connected together, and the test voltage shall be applied between the connected terminals and the shell.
When conducting the phase-to-phase voltage test, the capacitor terminals shall be disconnected before conducting the test. During the test, the voltage should be raised evenly from half of the rated voltage of the device or lower within 10s~30s to the test voltage specified in 5.3.2, and maintained at this voltage for the specified time. 6.6 Temperature rise test
During the temperature rise test, a voltage not lower than UN shall be applied to the device, and the test capacity shall be equal to 1.44QN during the entire temperature rise test. The test shall be carried out at room temperature.
The device shall be placed as in normal use. During the test, there should be enough time for the temperature rise to stabilize. Use a thermometer, thermocouple or other temperature measuring instrument to measure the hottest point temperature of the device shell and the temperature of the connection points between the wires in the device and between the wires and the electrical appliances once every 1h~2h. When the temperature change of 4 consecutive measurements within 6h does not exceed 1°C, the temperature is considered to be stable. 5
JB/T7115—1993
At the same time, the air temperature around the test object needs to be measured. At least two thermometers or thermocouples should be evenly arranged around the test object. The height of the arrangement point is approximately equal to half of the height of the test object, and the distance from the test object to 1m should be taken as the average value of the measured readings as the air temperature around the test object.
During the test, the ambient air temperature should not change too much, and the influence of air flow and heat radiation on the ambient air temperature should be prevented. 6.7 Protection test
6.7.1 Short-circuit protection test
Install the device according to normal use, and apply a voltage of 1.1U~ to the device. After the temperature stabilizes, short-circuit the capacitor inlet terminal and observe the action of the short-circuit protection device.
The expected short-circuit current during the test should be 2kA
If the short-circuit protection device has been subjected to a breaking test and a test report is available, this test may not be performed. 6.7.2 Overvoltage or overcurrent protection test
If the device is equipped with overvoltage or overcurrent protection, adjust the voltage or current of the input device during the test so that it exceeds the specified value of Article 5.1.4, and observe the action of the overvoltage or overcurrent protection device and the actuator (capacitors are not allowed to be connected). 6.8 Shell protection level inspection
The shell protection level should be inspected according to the test method specified in GB4208. 6.9 Discharge device inspection
If a discharge device is installed in the device, the method of measuring its self-discharge time is used for inspection. If the discharge device is a resistor type, the method of measuring resistance can also be used for inspection. After measurement, calculate according to the formula given in Appendix B of GB12747. Power-on operation test
If there is an operating device, it should be operated in normal use state, and the number of operations should be not less than 5 times. 7
Inspection rules
The test of the device is divided into: factory test, type test and acceptance test. 7.1 Factory test
The purpose of the factory test is to detect defects in manufacturing. This test is carried out by the manufacturer on each device produced. The test items are shown in Table 5.
Table 5 Test items
Test category
Factory test
Type test
Test items
Appearance inspection
Electrical component inspection
Capacitance inspection
Withstand voltage test
Discharge device inspection
Power-on probe operation test (if any)Withstand voltage test
Temperature rise testbzxz.net
Protection test
Enclosure protection grade inspection
Technical requirements Article number
5.2, 5.4.1, 5.4.4
Note: The order in Table 5 is a recommended order, and the manufacturer can choose the best order according to its own characteristics. Type test
Test method Article number
The purpose of type test is to examine whether the design, materials and manufacturing of the device meet the performance and use requirements specified in this standard6
JB/T7115—1993
Type test is carried out when new products are manufactured. In production, when there are changes in product structure, materials or processes, and the changes may affect the performance of the device, type test should also be carried out. At this time, only test items related to these changes are allowed. In the absence of the above changes, type test should also be carried out every five years. The device used for type test should be a device that has passed the factory test, and each type test does not necessarily have to be carried out on the same device.
Each type test item should have test data of at least two devices and a certificate of test results. It should be provided when the purchaser requires it.
See Table 5 for test items.
7.3 Acceptance test
Acceptance test is mainly a test carried out by the purchaser before installation. The purpose of this test is to check whether the device has been damaged during transportation, to ensure that the installed device is in good condition. When conditions permit, the recommended test items are as follows: Appearance inspection: Electrical component inspection: Capacitor inspection: Withstand voltage test. The device should have a nameplate indicating the following: a.
Name and model:
Rated voltage, kV:
Rated current, A:
Rated frequency, Hz;
Rated capacity, kvar:
Temperature category:
Weight, kg:
Standard code:
Manufacture date:
Number:
Manufacturer name or trademark.
Part of the content in the mark can be explained in the instruction manual. ②
The content in the mark should remain clear during the life of the device. 9
Storage, transportation and packaging
During storage and transportation, it should be ensured that the performance and quality of the device are not affected. 9.2 The packaging of the device should ensure that the device and the electrical components inside the device are not damaged under normal transportation conditions. 7
Installation and operation instructions
JB/T7115—1993
This chapter explains the main points that should be paid attention to during the installation and operation of the device. For detailed guidelines and instructions, please refer to the relevant regulations and manufacturer's instructions.
10.1 Application occasions for local compensation
The motor should mainly be in continuous working mode and have no large impact load. The motor shall not be subjected to reverse or reverse braking. The motor using speed control should not be equipped with reactive local compensation device. 10.2 Precautions
When the residual voltage of the device is greater than 10% of its rated voltage after the motor is powered off, it should not be put into operation again. When the motor uses a reduced pressure starter, it should not be switched on in an open circuit. In order to prevent self-excited overvoltage, the compensation capacity of the device shall generally not exceed the no-load capacity of the motor when the device and the motor are directly connected in parallel.
Wiring of the device
Depending on the size of the motor capacity and the nature of the load, the following are the common ways to connect the device to the motor power supply line: a. The device is installed on the power supply side of the starter (Figure 1a). At this time, the capacity of the device is not limited by the no-load excitation capacity of the motor, the working current of the starter is the same as when the device is not connected, and the overload protection setting value of the motor remains unchanged b. The device is installed between the starter and the overload protector (Figure 1b). At this time, the capacity of the device is limited by the no-load excitation capacity of the motor, the working current of the starter is reduced, and the overload protection setting value of the motor remains unchanged: c. The device is installed on the load side of the starter and the overload protector (Figure 1c). At this time, the capacity of the device is limited by the no-load excitation capacity of the motor, the working current of the starter is reduced, and the overload protection setting value of the motor is reduced d. The device is connected through a contactor (Figure 1d). When starting the motor, it is required to connect the device to the motor first, and when cutting off the motor, it is required to cut off the device at the same time.
JB/T7115—1993
Figure 1 Wiring of the device on the motor power supply line 1—Feeder; 2—Switch; 3—Fuse; 4—Local compensation device; 5—Starter; 6—Overload protector (thermal relay); 7—AC motor: 8—Contactor. 10.4 Operation and maintenance of the device
When the device is in operation, the actual operating voltage or current should be monitored to ensure that it does not exceed the provisions of Article 5.1.4. The device should be kept clean and tidy to prevent harmful dust pollution. Feng
The housing of the device should be reliably grounded. When opening the housing for maintenance, the capacitor should be discharged first, and the grounding wire should be connected to each capacitor terminal with an insulating rod before the capacitor terminal and lead can be touched. Additional remarks:
This standard was proposed by the National Technical Committee for Standardization of Power Capacitors. This standard is under the jurisdiction of the Xi'an Power Capacitor Research Institute. This standard was drafted by the Xi'an Power Capacitor Research Institute. The main drafter of this standard is Wang Jing.
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