MT/T 498-1995 CKJ series AC vacuum contactor maintenance inspection specification
Some standard content:
Coal Industry Standard of the People's Republic of China
CKJ Series AC Vacuum Contactor Maintenance
Inspection Technical Specifications
Subject Content and Scope of Application
MT/T 498—1995
This standard specifies the technical requirements, test methods and inspection rules for the maintenance inspection of CKJ series AC vacuum contactors. This standard applies to CKJ series AC vacuum contactors in use (hereinafter referred to as "contactors"). This standard does not apply to product identification inspection, factory inspection, type inspection and arrival acceptance of contactors. Other series of contactor maintenance inspections can also be used for reference. 2
Referenced standards
Basic standards for low-voltage electrical appliances
GB1497
Basic test methods for low-voltage electrical appliances
3 Technical requirements
3.1 Performance requirements
3.1.1 Dielectric properties
3.1.1.1 Power frequency withstand voltage:
The power frequency withstand voltage test values of the main circuit, control circuit and auxiliary circuit of the contactor shall comply with the provisions of Table 1. 3.1.1.2 Insulation resistance:
The insulation resistance of the main circuit and auxiliary circuit of the contactor shall not be less than that specified in Table 2. Table 1
Test partsbzxz.net
Main circuit
Control circuit and auxiliary circuit
Note: U is the rated value of the coil control voltage.
Test part
Main circuit
Auxiliary circuit
Rated insulation voltage
Rated working voltage, V
380,660
Approved by the Ministry of Coal Industry of the People's Republic of China on December 18, 1995 Power frequency test voltage (effective value)
2 U+1 000 (≥1 500)
Insulation resistance value, Ma
Implemented on May 1, 1996
3.1.2 Action performance
MT/T 498--1995
3.1.2.1 When the rated control power supply voltage U. is 75% to 110%, the contactor should be able to reliably close; when the control power supply voltage drops to 60% U., the contactor in the closed state should not release; in the case of contact wear, the minimum release voltage of the contactor should not be less than 20% of U. for AC (at rated frequency), and not less than 10% of U. for DC. The above specified values of the closing voltage and release voltage are applicable to the state after the line is subjected to 100% of U for a long time (8h working system) to achieve a stable temperature rise.
3.1.2.2 The inherent closing time difference of the same type of contactor shall not exceed 30ms; the inherent release time difference shall not exceed 40ms. 3.1.3 Contact opening distance and overtravel
Contactor contact opening distance shall meet product requirements, and its error shall not exceed 0.2~+0.2mm; overtravel value shall meet product requirements, and its error shall not exceed 0.1~0.2mm.
3.1.4 Vacuum quality of vacuum arc extinguishing chamber
3.1.4.1 The vacuum degree of vacuum arc extinguishing chamber shall not be less than 1.33×10-1Pa. 3.1.4.2 The contactor contact shall be able to withstand a test of not less than 7kV (AC is effective value) for 1min in the disconnected state. 3.1.5 Contact resistance
The contact resistance of the main contact shall be less than the control value specified in Table 3. Table 3
Tested contactor model
CKJ-125
CKJ-250
CKJ-400
CKJ-600
3.1.6 Contact resistance of main contactor when three phases of contactor are synchronously closed (or released).
When the contactor is closed (or released) under the rated working power supply voltage of the coil, the inherent closing (or releasing) response time difference of the three-phase contact should be less than 3ms.
3.1.7 Contact final pressure
Contactor contact final pressure should meet the requirements of product standards. 3.2 Structural requirements
3.2.1 Electrical clearance and creepage distance
3.2.1.1 Contactor electrical clearance should meet the relevant provisions of Article 7.1.3.1 of GB1497. 3.2.1.2 The creepage distance of the contactor shall comply with the relevant provisions of Article 7.1.3.2 of GB1497. 3.2.2 The wiring terminals
Maintain the original specification screws, and do not use other screws instead. 3.2.3 Other structural requirements
The overall dimensions and installation dimensions of the contactor shall comply with the technical requirements of the product; the metal parts of the contactor shall not have cracks, severe rust, or deformation, and the surface of the insulating parts of the contactor shall be smooth, without cracks or overburning; all screws, nuts, and washers of the contactor are complete, and the fastening measures are taken to prevent loosening; d.
During disassembly and assembly, the bellows shall not be subjected to torsion and shall not touch the air port; e.
The auxiliary circuit contacts shall be flat, smooth, without signs of overburning, and reliable in operation. f.
3.3 Temperature rise
When the test is carried out under the conditions specified in Article 4.10, the measured temperature rise of each component of the contactor shall not exceed the limit 144 specified in Table 4
Measurement location
Main circuit terminal
Auxiliary contact terminal
3.3.1 Main circuit temperature rise
MT/T 498-1995
Materials and plating
Silver plating (or nickel plating)
Silver, silver-based alloy
E grade insulation
B grade insulation
Allowable temperature rise
External wire is tin-plated copper
The main circuit of the contactor should carry the agreed heat current determined by the 8h working system and shall not exceed the limit value specified in Table 4. 3.3.2 Auxiliary circuit temperature rise
The auxiliary circuit should be able to carry the agreed heating current without exceeding the limit value specified in Table 4. 3.3.3 Coil temperature rise
When the main circuit is energized, the winding of the contactor coil must withstand the rated control power supply voltage under continuous power supply and rated frequency, and the temperature rise does not exceed the limit value specified in Table 4.
When there is no current passing through the main circuit, under the premise of the same power supply conditions and not exceeding the temperature rise limit, it withstands the rated operating frequency and the load factor is 40%.
4 Test method
4.1 Test conditions
This test should be carried out under the following environmental conditions: a.
Temperature: -5～+40℃
Average relative temperature: 45%～75% (+25℃) b.
Atmospheric pressure: 86～106kPa
4.2 Dielectric performance test
4.2.1 Contactor conditions for the test:
The surface of the contactor under test should be clean and dry. Install it in the normal working position, and the semiconductor devices of the control circuit should be removed. 4.2.2 Voltage application location:
4.2.2.1 Main circuit:
During the test, the control circuit and auxiliary circuit should be connected to the metal bracket of the contactor. 4.2.2.1.1 When the main contact is closed:
Between the live parts of all poles connected together and the metal support of the contactor; a.
Between each pole and the other poles connected to the metal support of the contactor. b.
4.2.2.1.2 When the main contact is open:
Between the live parts of all poles connected together and the metal support of the contactor, and between the terminals on one side connected together and the terminals on the other side connected together. b.
4.2.2.2 Control circuit and auxiliary circuit.
During the test, the main circuit is connected to the metal support of the contactor a.
Between the coil and the metal support of the contactor;
Between the auxiliary contact and the metal support of the contactor; Between the inlet and outlet lines of the auxiliary contact;
d. Between the normally closed and normally open contacts;
Between the terminals of the terminal;
f. Between the terminal and the metal base.
MT/T 498-1995
4.2.3 The test voltage shall be in accordance with the requirements of 3.1.1.1 and Table 1. 4.2.4 The time for applying voltage is 1 minute. It should start from less than 1/2 of the test voltage, gradually increase the voltage to the specified value in about 5 seconds, and then continue for 1 minute. After the pressure is applied, sudden loss of pressure should be avoided. 4.2.5 Requirements for test equipment: The voltage of the test power supply should be a sine wave with a frequency between 45 and 62Hz. When its high-voltage output terminal is short-circuited, the current should not be less than 0.5A, and the sensitive relay for detecting leakage current should be adjusted to operate at 100mA. 4.2.6 Insulation resistance measurement: The voltage level of the megohmmeter for measuring the insulation resistance of the main circuit, auxiliary circuit, and control circuit is the value specified in Table 5. The insulation resistance requirements are in accordance with the values specified in Table 2 of 3.1.1.2. However, for the case of parallel connection of each level, as long as the insulation resistance between each pole or between each pole and the metal bracket of the contactor meets 3.1.1.2 requirements are considered qualified. Table 5
Main circuit
Auxiliary circuit and control circuit
Rated working voltage
380,660
Megohmmeter voltage level
4.3 Action performance test
4.3.1 When the main circuit of the contactor is not energized, the coil is in a cold state and the coil circuit is quickly disconnected at the power supply voltage specified in Article 3.1.2.1. At this time, the contactor contacts should be accurately disconnected; when the coil is in a hot state, the coil circuit is quickly closed at the power supply voltage range specified in Article 3.1.2.1. At this time, the contactor contacts should be accurately closed. 4.3.2 The contactor operates flexibly and reliably without scratching. 4.3.3 The time difference between the rated coil working voltage and the main contact closure response of the same type of contactor shall not be greater than the value specified in 3.1.2.2; the time difference between the rated coil working voltage and the main contact release response of the same type of contactor shall not be greater than the value specified in 3.1.2.2. 4.4 Measurement of contact opening distance and overtravel
4.4.1 Measurement of contact opening distance:
4.4.1.1 When the contactor is disconnected, measure the distance between the moving contact and the static contact. 4.4.1.2 Measure the distance between the moving contact and the metal bracket when the contactor is closed and disconnected to obtain the contact opening distance value. 4.4.2 Measurement of contact overtravel:
The contact overtravel measurement method complies with Article A1 of GB998. 4.5 Vacuum quality test
4.5.1 When measuring vacuum quality by magnetron method, the requirements of 3.1.4.1 shall be met; when measuring vacuum quality by high voltage withstand method, the requirements of 3.4.1 shall be met. 4.5.2 Either of the two test methods listed in 4.5.1 may be adopted. 4.5.2.1 Requirements for contactors under test
Remove the contactor, and the contactor surface shall be clean and dry; a.
Related components connected to the main contacts shall be removed; the contactor is in the disconnected state;
Apply voltage to both ends of the main contacts of the contactor;
The contactor base shall be suspended.
4.5.2.2 The contacts shall be able to withstand the test voltage specified in 3.1.4.2 at the specified opening distance. After three withstand voltage tests, breakdown and 146
continuous flashover are not allowed.
MT/T498—1995
4.5.2.3 The applied voltage should start from 1/2 of the test voltage, and gradually increase to the specified value in about 5s, and then continue for 1min. During the test, several sparking phenomena are allowed to occur in the vacuum interrupter, as long as it can finally rise to the specified withstand voltage value. After the pressurization is completed, sudden pressure loss should be avoided. 4.6 Contact resistance test
4.6.1 When testing the contact resistance of the main contact of the contactor, place the contactor vertically on the test bench. When the main contact is not energized, the contactor is continuously opened and closed 4 times to ensure good contact of the contact. 4.6.2 When the contactor is in the closed state, the two ends of the test clamp of the contact resistance tester are closely contacted with the two ends of the main contact of the contactor, and the resistance value is read from the meter.
4.6.3 Repeat the test three times according to 4.6.1 and 4.6.2, and take the arithmetic average of the three measured values. 4.7 Three-phase synchronous time difference measurement
4.7.1 Instrument measurement:
Contactor, under the rated working power supply voltage of the coil, starts timing from the coil being energized (or de-energized) to the end of the three-phase main contact being pulled in (or released), and subtracts the inherent pull-in (or release) response time value of each phase to obtain the inherent pull-in (or release) response time difference of the three-phase main contact. 4.7.2 Waveform measurement:
Apply voltage to both ends of the three-phase main contact. When the contactor is pulled in (or released), the amplitude of the voltage waveform on the main contact is not less than 25mm, and the recording speed should be not less than 1m/s. The pull-in (or release) response time difference of the three-phase main contact is obtained by visual method. 4.8 Contact final pressure measurement
4.8.1 The final pressure measurement of the contact should be measured by a force measuring instrument in the closed position. 4.8.2 The force measuring instrument should apply force along the normal direction of the contact surface at the specified working point. If the above requirements are not met, appropriate conversion must be performed.
4.8.3 When the indicator in the series circuit with the contact just generates a signal, the reading value of the force measuring instrument is the final contact pressure value. 4.9 Inspection
Inspect 3.2.1, 3.2.2, and 3.2.3 by appearance, feel, and caliper. 4.10 Temperature rise test
4.10.1 Temperature rise test of main circuit:
The selection of connecting wires for temperature rise test shall be in accordance with the provisions of Table 6Table 6
Agreed heating current
4.10.2 Temperature rise test of coil:
PVC cable
Cross section, mm
The temperature rise test of coil shall be carried out in the following two ways: Connect
a The main circuit is connected with agreed heating current, and the rated control voltage is continuously applied to the coil until the temperature rise is stable; Cross section, mm
b No current is passed through the main circuit, and the rated control voltage is periodically applied to the coil at the rated operating frequency with a load factor of 40% until the temperature rise is stable.
4.10.3 Temperature rise test of auxiliary circuit:
MT/T 498-1995
The wire for the temperature rise test of auxiliary circuit shall be selected as PVC copper wire with a cross section of 1mm2 and a length of not less than 1m. Temperature rise regulations In addition to the above provisions, the rest shall be in accordance with the relevant provisions of GB998 Article 5 Temperature rise test. 5 Inspection rules
5.1 Inspection types
Inspections are divided into three categories: underground patrol inspection, regular inspection and emergency inspection. Underground patrol inspection is carried out during routine inspection of explosion-proof switches. Regular inspection is carried out according to the equipment maintenance cycle. Emergency inspection is carried out when the contactor has the following situations: abnormal phenomenon occurs;
b, after opening and closing short-circuit accident current;
When it is affected by other working conditions and needs maintenance. c.
5.2 Inspection items
Inspection items are shown in Table 7
Inspection items
Dielectric properties
Action performance
Opening distance and overtravel
Vacuum quality
Contact resistance
Three-phase synchronous performance
Contact final pressure
Structure and appearance
Technical requirements
, one conditional project.
Note: Required project△
5.3 Inspection judgment
Test requirements
Underground inspection
Periodic inspection
Emergency inspection
5.3.1 In the dielectric performance test of Article 4.2, if there is no breakdown or flashover phenomenon, no relay operation or sudden voltage drop due to obvious increase in leakage current, the dielectric performance test is considered to be qualified. 5.3.2 In the action performance test of Article 4.3, if the test results meet the requirements of Article 3.1.2, the action performance test is considered to be qualified. 5.3.3 In the process of measuring the opening distance in Article 4.4.1, the contact opening distance can be adjusted according to the requirements of the contactor. If its value meets the requirements of Article 3.1.3.1, the opening distance test is considered to be qualified. In the overtravel measurement in Article 4.4.2, if the measurement results meet the requirements of Article 3.1.3.2, the overtravel test is considered to be qualified. 5.3.4 In the vacuum quality test in Article 4.5.1, if the test results meet the requirements of Article 3.1.4.1, the vacuum quality test is considered to be qualified. In the process of the high-voltage withstand voltage test in Article 4.5.2, if no insulation breakdown or continuous flashover occurs, the vacuum quality test is considered to be qualified. 5.3.5 In the contact resistance measurement in Article 4.6, if the measurement results meet the requirements of Table 3 in Article 3.1.5, the contact resistance test is considered to be qualified. When
exceeds the specified value, it is necessary to conduct a temperature rise test assessment. In the temperature rise test of Article 4.10, if the temperature rise test results of various parts of the contactor meet the requirements of Article 148
3.3, the temperature rise test is considered to be qualified. MT/T498-1995
5.3.6 In the three-phase synchronous time difference measurement of Article 4.7, the contactor opening distance and reaction spring can be adjusted so that the measurement results meet the requirements of Article 3.1.6. If the adjusted opening distance still meets the requirements of Article 3.1.3.1, the three-phase synchronous time difference test is considered to be qualified. 5.3.7 In the contact final pressure measurement of Article 4.8, if the measurement results meet the requirements of Article 3.1.7, the contact final pressure test is considered to be qualified. 5.3.8 In the structural inspection of Article 4.9, the contactor appearance, wiring terminals and auxiliary contacts can be appropriately adjusted and repaired to meet the requirements of Article 3.2. If any of the provisions of Article 3.2 is not met due to the inability to repair, the structural inspection is considered to be unqualified. 5.3.9 After all the specified inspection items of the contactor are qualified, the specified maintenance unit shall issue a maintenance certificate before the contactor can continue to be used. Additional notes:
This standard is proposed by the Coal Mine Special Equipment Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Electrical Branch of the Coal Mine Special Equipment Standardization Technical Committee. This standard was drafted by the Beijing Well Construction Research Institute of the China Coal Research Institute, and was participated in by the Tangshan Mine of the Kaishen Mining Bureau, Xin'anjiang Electronic Tube Factory, and Jiangyin Mining Equipment Factory.
The main drafters of this standard are Yang Yiqing and Zhang Jian. This standard is entrusted to the Beijing Well Construction Research Institute of the China Coal Research Institute for interpretation. 149
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