Some standard content:
1CS.29.200
Record number: 103082002
Coal Industry Standard of the People's Republic of China
MT68-2002
Charging racks for caplamps
Published on April 8, 2002
National Economic and Trade Commission
Implemented on September 1, 2002
MT68-2002
Articles 4.3.8, 4.4.2 and 4.4.5 of Chapter 4 of this standard are mandatory, and the rest are recommended. This standard is based on the continuous development of mining lamp manufacturing technology and mining lamp charging control technology, and is a revision of MT/T68-1992 General Technical Conditions for Automatic Voltage Controlled Acid Mining Lamp Charging Racks and MT129-1985 General Technical Conditions for Alkaline Mining Lamp Charging Racks. This standard classifies all kinds of charging racks for mining lamps (acidic and alkaline), and the name of the standard is changed to "Mining Lamp Charging Rack" accordingly, which improves the applicability of the standard. On the basis of MT/T68-1992 and MT129-1985, the product model compilation method, wet heat performance test, and dust and antistatic test of charging indicator are added.
Appendix A and Appendix B of this standard are the appendices of the standard. This standard replaces MT/T68-1992 and MT129-1985 from the date of entry into force. This standard is proposed by the China Coal Industry Association. This standard is under the jurisdiction of the Coal Industry Coal Mine Special Equipment Standardization Technical Committee. This standard is drafted by the Shanghai Branch of the China Coal Research Institute, and the Meishan Mining Lamp Factory participated in the drafting. The main drafters of this standard are: Yang Binghe, Hu Feilong, Gu Yuanting, and Jian Caiyun. This standard is entrusted to the Electrical Equipment Branch of the Coal Industry Coal Mine Special Equipment Standardization Technical Committee for interpretation. 1 Scope
Coal Industry Standard of the People's Republic of China
Charging racks for cap lamps
Charging racks for cap lampsMT68—2002
Replaces MT/T68-1992
MT129—1985
This standard specifies the product classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of charging racks for cap lamps used indoors on the ground of coal mines.
This standard applies to charging racks for cap lamps.
2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T2423.3—1993 Basic environmental test procedures for electric and electronic products Test Ca: Steady state damp heat test method
(eqvIEC68-2-3:1974)
GB/T2423.4-—1993E Basic environmental test procedures for electric and electronic products Test Db: Alternating damp heat test method
(eqvIEC68-2-30:1980)
GB/T3859.1~3859.3—1993 Semiconductor Inverter GB/T14048.1--1993 General rules for low-voltage switchgear and control equipment (eqvIEC947-1:1988) MT/T455-1995 Method for compiling and managing product models of mining lamp charging racks JB/T4159-1999 General technical requirements for tropical electrical products 3 Product classification
3.1 Product type
The mining lamp charging rack consists of a shell (a frame shell composed of thin steel plate components or a plastic molded shell), a charging mechanism for a current converter, and a charging indicator. The rack shell can be divided into two types: vertical cabinet type and horizontal type according to the installation method of the current converter. 3.2 Product model compilation
The method for compiling product models should comply with the provisions of MT/T455. 3.3 Main technical parameters
3.3.1 Rated AC voltage: single-phase 220V, three-phase 380V. 3.3.2 Rated power supply rate 50Hz.
3.3.3 Rated working system: long-term working system. 3.3.4 Rated DC parameters shall comply with the provisions of Table 1. Approved by the State Economic and Trade Commission on April 8, 2002 and implemented on September 1, 2002
Rated DC voltage/V
Rated DC current per charging position/A
Note: Charging parameters of other types of mining lamps shall be in accordance with their respective technical conditions 4
Technical requirements
4.1 Manufacturing
MT682002
Acid charging rack
Rated capacity of mining lamp
9~10Ah
>10 Ah
The charging rack shall comply with the requirements of this standard and be manufactured in accordance with the drawings and technical documents approved in the prescribed procedures. 4.2 Normal use conditions
Alkaline charging rack
4.2.1 The altitude shall not exceed 1000m (when the altitude of the operating location is greater than 1000m, its load capacity shall be corrected according to the curve in Appendix A (Appendix of the standard) of this standard).
4.2.2 The average relative humidity of the surrounding air shall not exceed 90% (when the ambient air temperature is (20±5)℃). 4.2.3 The indoor ambient temperature shall not be lower than -5℃ and not higher than +40℃. 4.2.4 No violent vibration.
4.2.5 No conductive dust, good ventilation.
4.2.6 The fluctuation range of the voltage amplitude of the AC power grid shall not exceed ±10% of the rated value. Note: If the above normal use conditions are not met, the corresponding requirements shall be made to the supplier and an agreement shall be obtained when ordering. 4.3 Structural and assembly requirements
4.3.1 The overall frame structure shall be stable and rigid. 4.3.2 The frame panel should be flat and free of obvious unevenness. 4.3.3 The edges and openings of frame parts should be flat and smooth, without burrs and cracks. 4.3.4 Plastic molded shells and other products should have sufficient strength and thermal stability, and the surface should be flat without defects such as flash, cracks, and bubbles.
4.3.5 The surface of the parts of the frame that are in contact with acid or alkali should be coated with an acid-resistant or alkali-resistant protective layer, and the remaining parts can be painted with decorative paint. The appearance requirements of the paint film should comply with the "three-level processing" requirements in JB/T4159-1999. 4.3.6 The electroplated parts should have uniform color, and no debris visible to the naked eye is allowed. The quality of the plating should comply with the "three-level processing" requirements in GB/T2423.3-1993.
4.3.7 The frame panels that are in contact with acid or alkali should be covered with acid-resistant and alkali-resistant protective plates. 4.3.8 The electrical clearance and creepage distance between the exposed live conductors in different parts of the charging rack and between the charging rack and the casing should not be less than the requirements in Table 2. The electrical clearance and creepage distance of each component shall comply with the relevant provisions of GB/T14048.1. Table 2
Charging mechanism
Primary circuit
Secondary circuit
Electrical clearance
Climbing distance
4.3.9 The metal frame casing shall be equipped with a grounding terminal and an obvious grounding mark. The minimum size of the grounding screw shall not be less than M6. Each charging position of the charging rack shall be equipped with a charging indicator device. 4.3.10
4.3.11 The power switch adjustment potentiometer of the charging rack must have an operation mark, and each charging circuit shall be marked with a serial number. MT68-2002
4.3.12 Charging machine The structure should ensure that the insertion, rotation and removal of the mining lamp head are flexible and reliable. 4.3.13 The wiring in the frame should be horizontal and vertical, neat and beautiful, the conductive parts should be in good contact, the connection should be firm and equipped with anti-loosening devices. 4.3.14 Raw materials and supporting components should comply with the standards of relevant departments and be accompanied by product certificates. 4.3.15 The wearing parts of products of the same model must be replaceable. 4.4 Performance requirements
4.4.1 The load level is level 1 (100% rated current continuous). 4.4.2 Charging stability:
a) Automatic voltage control type: When the device load changes from 10% to 100% of the rated value and the AC grid voltage changes by ±10% of the rated value, each charging The rated output voltage stability accuracy of the charging potential shall not be less than ±2%. b) Self-flow automatic control type: Under the conditions that the load of the device changes from 10% to 100% of the rated value and the AC grid voltage changes from ±10% of the rated value, the rated output current stability accuracy of each charging potential shall not be less than ±10%. 4.4.3 The insulation resistance of the conductive part of the charging rack to the ground shall not be less than 1Mα. 4.4.4 The wet heat performance of various inductive components and switch components in the charging rack converter shall comply with the assessment of the alternating wet heat test of GB/T2423.4. The wet heat test cycle is 6d, and the high temperature is 40℃. After the test, the insulation resistance shall not be less than 1MQ, and the insulation strength shall comply with the provisions of Table 3.
4.4.5 The insulation strength of the charging rack shall comply with the power frequency test voltage specified in Table 3. There shall be no breakdown or flashover for 1 minute. Table 3
Test location
AC input terminal to ground
DC output terminal to ground
4.4.6 Electrical efficiency:
Test voltage
2.5 (when AC input is 380V)
2 (when AC input is 220V)
Test location
In air
In air
a) When the rated output power of the charging rack is greater than 0.7kW, the electrical efficiency is guaranteed to be 65%, and the minimum efficiency tolerance is 1%. b) When the rated output power of the charging rack is less than 0.7kW, the electrical efficiency shall be based on the respective technical conditions of the product. 4.4.7 The limit temperature rise of different components and parts of the charging rack shall not exceed the values specified in Table 4. Table 4
Device or component
Transformer line purchase
Reactor
Insulation level
Copper busbar (bare copper) screw
Busbar (with tinned layer) fixing
Limit temperature rise
Measurement method
Electric limit method
Thermocouple method or thermometer method
Note: The agreed heating current is the rated working current of the charging rack. The limit temperature rise in the installation is based on the ambient temperature of 40℃. For the use conditions where the ambient temperature is lower than 40℃, the limit temperature rise in the table can be adjusted within the allowable working range of the insulation material used. 4.4.8 The mechanical life of the charging structure (including plug, charging seat, contact seat) of the charging rack should be no less than 3000 times. 4.4.9 The technical requirements of the charging indicator device (electromagnetic pointer type) of the charging rack shall comply with the provisions of Appendix B (Appendix of the standard) of this standard. Other charging indicator devices shall comply with the respective technical conditions of the product. 4.4.10 The accuracy of the electrical instruments on the charging rack should not be lower than Class 1.5. 5 Test methods
5.1 Appearance and assembly quality inspection
Inspect according to the drawings and actual samples in accordance with the requirements of 4.1 and 4.3. 3
5.2 Charging circuit on-off test
MT682002
After the charging rack is powered on and the charging voltage is adjusted to the normal range, use a miner's lamp to check each circuit one by one. Each charging circuit should be connected correctly and well. 5.3 Electrical clearance and creepage distance
Use a vernier caliper with an accuracy of not less than 0.02mm to detect. 5.4 Charging mechanism life test
Under the conditions of power on and normal charging voltage, insert the qualified miner's lamp head into the plug, turn it 180° clockwise, so that the charging contact of the miner's lamp head presses the spring-fed piece tightly, then withdraw and take it out, and repeat 3000 times. The charging plug shall not be deformed, broken or loose, the charging seat shall not be slipped or damaged, the spring sheet shall not be permanently deformed, broken or ejected, and can continue to be used normally. 5.5 Insulation test
Measure the insulation resistance of the tested part according to the requirements of GB/T14048.1. 5.6 Wet heat performance test
Carry out according to the method specified in GB/T2423.4. The tested outsourcing parts shall provide this test report. Switching electrical appliances with a withstand voltage below 220V shall not be assessed.
5.7 Insulation strength test
Test the parts specified in 4.4.5. The test transformer capacity shall not be less than 2kVA, and the time for the test voltage to rise to full voltage shall not be less than 10s.
5.8 Temperature rise test
Carry out according to the relevant provisions of GB/T14048.1 temperature rise test. 5.9 Electrical efficiency test
5.9.1 During the temperature rise test, carry out after the heat is stable. 5.9.2 Under the conditions of rated input and output voltage and rated output current, use a power meter to measure the active power of the AC input, and use a DC voltmeter and DC ammeter to measure the DC output power, and then calculate the measured electrical efficiency according to formula (1). AC input active power × 100%
DC output power
Electrical efficiency-
5.10 Charging stability test
5.10.1 Voltage stability:
Use an AC voltage regulator, a resistive load and an adjustable potentiometer on the charging rack to perform the test in accordance with the provisions of 4.4.2. After the test, the voltage stability accuracy calculated by formula (2) should meet the requirements of 4.4.2a) (randomly select one or several charging positions to measure the output). 5.10.2 Current stability:
Use an AC voltage regulator, a miner's lamp as a load and an adjustable potentiometer on the charging rack to perform the test in accordance with the provisions of 4.4.2. After the test, the current stability accuracy calculated by formula (2) shall meet the requirements of 4.4.2b) (randomly select a number of charging positions to measure the output). Output limit value - rated value × 100%
Stable accuracy-
6 Inspection rules
6.1 Inspection classification
Product inspection is divided into factory inspection and type inspection. 6.2 Factory inspection
Rated value
6.2.1 The charging rack must be factory inspected one by one according to the factory inspection items specified in Table 5. ++++++(2)
6.2.2 If there are unqualified items during the factory inspection, it is allowed to be returned for retesting, and the factory inspection certificate can only be issued after passing the inspection. 6.3 Type inspection
6.3.1 Type inspection shall be carried out in any of the following cases: a) Trial design and evaluation of new products or old products transferred to the factory for production: 4
MT68-—2002
b) After formal production, if there are major changes in structure, materials, and processes that may affect product performance; c) During normal production, periodic inspection shall be carried out; d) Resuming production after product suspension;
e) When the national quality supervision and inspection agency makes a request; f) When there is a major difference between the factory inspection results and the last type inspection results. 6.3.2 The inspection items, technical requirements, test methods and inspection cycles of type inspection shall comply with the provisions of Table 5. Table 5
Inspection items
Appearance and assembly quality inspection
Charging circuit continuity test
Electrical clearance and creepage distance
Charging mechanism life test
Insulation test
Wet heat performance test
Insulation strength test
Temperature rise test
Electrical efficiency test
Charging stability test
Technical requirements
Test method
Inspection category
Factory inspection||t t||Type inspection
Type inspection cycle
Every six months
Every six months
Every six months
Every six months
Every six months
Every six months
Every six months
Every six months
Every six months
6.3.3 The number of type inspections shall not be less than 2 units per batch. If one unit fails to meet the requirements of one item (mandatory item) during the test, the type inspection shall be deemed to have failed. If one unit fails to meet the requirements of one item (non-mandatory item) during the test, it shall be allowed to return for retest or double sampling of the unqualified items. If the unqualified items are still unqualified, the batch of products shall be deemed to have failed. Production can only be continued after the products have been repaired and passed the test. 6.3.4 After the products have passed the inspection, the national authorized inspection unit shall issue a "certificate of inspection" with a validity period of 3 years. 6.3.5 The inspection unit has the right to re-inspect the products that have been issued with the "inspection certificate". If it is found that the quality of the original inspected product is not in line with the original inspection product, it can make suggestions to the manufacturer and revoke the original "inspection certificate" if necessary. 6.4 If the purchaser (user) has objections to the product quality, it can ask the supplier (manufacturer) to re-inspect the product. The factory inspection re-inspection quantity is 5%, but not less than 2 units. Although the type inspection re-inspection is 2 units, it can also be carried out according to the agreement between the two parties. 7 Marking, packaging, transportation, purchase and storage
7.1 Marking
7.1.1 A nameplate should be installed in a conspicuous position on the charging rack. 7.1.2 Contents of the charging rack nameplate:||tt| |a) Product model and name;
b) Trademark and manufacturer's name;
c) AC input voltage;
d) Power frequency;
e) DC output voltage;
f) DC output current;
g) Product number;
h) Product quality;
i) Manufacturing date.
7.2 Packaging
7.2.1 Technical documents supplied with the product: a) Product certificate;
b) Product installation and use instructions;
c) List of product sets and spare parts.
7.2.2 Product packaging:
MT68—2002
Product packaging must comply with the relevant packaging and transportation specifications, and should ensure that the product is not mechanically damaged during transportation and storage, and has rain and dust protection capabilities. The following signs should be marked on the outside of the packaging box: a) Product model, name and factory number; b) Product net weight, gross weight and quantity;
c) Name and address of the manufacturing unit;
d) Position mark "" and the word "upward" written above the arrow; e) Package box dimensions;
f) Packing date.
7.3 Transportation
The product should not be subjected to severe vibration, impact or inversion during transportation. 7.4 Storage
The product shall not be exposed to direct sunlight or rain, and shall be stored in a well-ventilated place with the ambient medium temperature not higher than 1040℃ and not lower than -40℃, and the maximum relative humidity of the air not exceeding 90% (in a warehouse with an ambient air temperature of (20±5)℃ and no corrosive gas). 6
MT68-2002
Appendix A
(Appendix to the standard)
Correction of current capacity when used in high altitude areas A1 When power semiconductor devices and equipment are used at an altitude higher than 1000m, the current capacity of the semiconductor devices and equipment will be lower than the specified value due to the thin air, which affects the heat dissipation conditions. Figure A1 shows the relationship curve between current capacity and altitude. It is assumed here that the cooling medium The quality temperature remains unchanged. The increase in altitude will also cause the average ambient temperature to drop. According to my country's climatic characteristics, the ambient temperature drops by 0.5C for every 100m increase in altitude. Therefore, when correcting the current capacity of the converter used in high-altitude areas, the unfavorable factor that the current capacity decreases with increasing altitude and the favorable factor that the ambient temperature decreases should be considered at the same time. 500
Altitude/m
B1 Technical requirements
B1.1 Basic error: ±10%.
MT68-2002
Appendix B
(Appendix to the standard)
Technical conditions for electromagnetic charging indicators
This technical condition is only applicable to the charging indicator of the mining lamp charging rack. B1.2 Range :0~3A,0~5A.
B1.3 Scale lines: There should be no less than five scale lines, namely 0A, 0.5A, 1A2A, 3A or 0A0.5A, 1A, 3A, 5A. B1.4 Rise and fall variation: It should be less than 1.5 times the absolute value of the basic error. B1.5 No return to zero: Less than 3mm.
B1.6 Insulation resistance: The insulation resistance between the terminal screws and the casing should not be less than 1MQ. B1.7 Dielectric strength: It should be able to withstand a power frequency voltage of 0.5kV for 1min between the terminal screws and the casing. B1.8 Constant damp heat: The performance of the charging indicator after the constant damp heat test should meet the requirements of B1.6 and B1.7 B1.9 Overload resistance: It should be able to withstand 120% of the rated value Current load for 2h, should be able to withstand 9 times of the rated value of the impact current (each duration of 0.5s, interval between each time of 1min, and a duration of 5s impact load). After the load test, the charging indicator should meet the requirements of B1.1, B1.4, and B1.5 after cooling to room temperature. Note: It is allowed to adjust with a zero adjuster.
B1.10 Mechanical performance: The charging indicator should be able to withstand the transportation shock test of 30m/s and 80~120 times per minute under the conditions of transportation packaging for 2h. There should be no damage after the test and meet the requirements of B1.1, B1.4, B1.5, and B1.6. B1.11 Dust and anti-static requirements for the shell: No dust should enter the inside of the shell. When wiping the shell, the indication value of the indicator pointer should not be affected by the static electricity of the shell.
B2 Test method
B2.1 Basic error, rise and fall variation, non-zero return detection conditions: B2.1.1 The temperature of the charging indicator should be the same as the ambient temperature, and various tests should be carried out after preheating for 15 minutes under rated load. B2.1.2 Various tests and comparisons should be carried out after the overload test and mechanical force resistance performance test (comparison of the charging indicator reading with the reading of the standard instrument).
B2.2 Basic error test:
From the test results obtained by steadily increasing and decreasing the measured value, take the maximum difference between the indicated value of the charging indicator and the actual value of the measured value (standard meter reading).
B2.3 Range and scale line inspection:
Visual inspection.
B2.4 Rise and fall variation test:
When the measured current value gradually increases and decreases, the tested charging indicator is steadily moved to a certain point on the scale line, and the maximum value of the actual difference between the two measured values is taken.
B2.5 Non-zero return test:
During the test of basic error, when the charging indicator stays at the end scale line of the effective range of the scale line, and then steadily decreases to zero (disconnect the line), read the non-zero value within 10s. B2.6 Dielectric strength test:
Within 5 to 10s, the voltage steadily increases from zero to 0.5kV and is maintained for 1min without insulation breakdown and flashover. 8
B2.7 Constant humidity test:
MT68—2002
The test sample should be placed at (40±2)°C and relative humidity of 93%±3% for 6h. After being taken out, the insulation resistance (using a 500V megohmmeter) and insulation strength should be measured immediately without condensation. B2.8 Overload resistance test:
Short-term overload and impact tests should be carried out in an inductive circuit and in accordance with the contents specified in B1.9. B2.9 Mechanical force resistance performance test:
The test piece shall be installed vertically on the vibration test device and carried out according to the content specified in B1.10. B2.10 Dust and antistatic test:
It shall be carried out in a sealed box with a circulating air speed of not less than 5m/s for 15 minutes. The volume of the box shall exceed the volume of the charging indicator by 5 times. Before the test, pine pollen or fluorescent powder, quartz powder, etc. equivalent to 0.1% of the volume shall be placed in the box. After the test, the powder on the surface of the shell shall be removed and the shell shall be opened. There shall be no dust inside the meter.
When conducting the basic error test, wipe the indicator surface with a test cloth. The basic error after the test shall be consistent with the basic error when the test cloth is not wiped.
B3 Inspection rules
B3.1 The inspection of the charging indicator is divided into factory inspection and type inspection. B3.2 Factory inspection includes the following test items: a) Basic error test;
b) Range and scale line inspection;
c) Rise and fall variation test;
d) Non-zero return test;
e) Dielectric strength test;
f) Dielectric resistance test;
g) Mechanical force resistance test.
B3.2.1 The number of random tests for factory inspection is 0.5% of the number of products in this batch, but not less than 3. If one item fails during the test, the unqualified item shall be double sampled for inspection. If it still fails, the batch of products shall be judged as unqualified. B3.3 Type inspection shall be carried out in the following circumstances: a) When the product has changed in structure, process or main materials, which affects the product performance; b) When the product is put into production again after being discontinued for a long time; c) When new products are being trial-formed;
d) When users have objections to product quality and make requests: e) Random inspection shall be carried out every 3 years.
B3.3.1Contents of type inspection:
All requirements of this appendix.
B3.3.2The number of random inspections for type inspection shall be no less than 3 products among the qualified products. If there are unqualified items, double sampling shall be conducted for the unqualified items. If the unqualified items are still unqualified, the product shall be deemed to have failed the type inspection. 95C. Therefore, when correcting the current capacity of the converter used in high altitude areas, the unfavorable factor that the current capacity decreases with the increase of altitude and the favorable factor that the ambient temperature decreases should be considered at the same time. 500
Altitude/m
B1 Technical requirements
B1.1 Basic error: ±10%.
MT68-2002
Appendix B
(Appendix to the standard)
Technical conditions for electromagnetic charging indicators
This technical condition is only applicable to the charging indicator of the mining lamp charging rack. B1.2 Range: 0~3A, 0~5A.
B1.3 Graduation lines: There should be no less than five graduation lines, which are 0A, 0.5A, 1A2A, 3A or 0A0.5A, 1A, 3A, 5A. B1.4 Rise and fall variation: It should be less than 1.5 times the absolute value of the basic error. B1.5 Non-zero return: less than 3mm.
B1.6 Insulation resistance: The insulation resistance between the terminal screw and the housing should not be less than 1MQ. B1.7 Insulation strength: It should be able to withstand a test of 0.5kV power frequency voltage for 1 minute between the terminal screw and the housing. B1.8 Constant damp heat: The performance of the charging indicator after the constant damp heat test should meet the requirements of B1.6 and B1.7. B1.9 Overload resistance: It should be able to withstand a current load of 120% of the rated value for 2h, and should be able to withstand 9 times the rated impact current (each time lasting 0.5s, the interval between each time is 1min, and a shock load lasting 5s). After the charging indicator that has undergone the load test cools to room temperature, its performance should meet the requirements of B1.1, B1.4, and B1.5. Note: It is allowed to adjust with a zero adjuster.
B1.10 Mechanical resistance performance: The charging indicator should be able to withstand a transportation shock test of 30m/s acceleration and 80~120 impacts per minute for 2h under the condition of transportation packaging. There should be no damage after the test and meet the requirements of B1.1, B1.4, B1.5, B1.6. B1.11 Dustproof and antistatic requirements for the case: Dust should not enter the inside of the case. When wiping the case, the indication value of the indicator pointer should not be affected by the static electricity of the case.
B2 Test method
B2.1 Basic error, lifting variation, non-zero return detection conditions: B2.1.1 The temperature of the charging indicator should be the same as the ambient temperature, and various tests should be carried out after preheating for 15min under rated load. B2.1.2 Various tests and comparisons should be carried out after the overload test and mechanical resistance performance test (the charging indicator reading is compared with the reading of the standard instrument).
B2.2 Basic error test:
From the test results obtained by steadily increasing and decreasing the measured value, take the maximum difference between the indicated value of the charging indicator and the actual value of the measured value (standard meter reading).
B2.3 Range and scale line inspection:
Visual inspection.
B2.4 Rising and falling variation test:
When the measured current value gradually increases and decreases, the tested charging indicator is steadily moved to a certain point on the scale line, and the maximum value of the actual difference between the two measurements is taken.
B2.5 Non-zero return test:
During the basic error test, when the charging indicator stays at the end division line of the effective range of the scale line, and then steadily decreases to zero (disconnect the line), read the non-zero value within 10s. B2.6 Insulation strength test:
Within 5 to 10 seconds, the voltage increases steadily from zero to 0.5kV and is maintained for 1 minute without insulation breakdown and flashover. 8
B2.7 Steady damp heat test:
MT68—2002
The test sample should be placed at (40±2)°C and relative humidity of 93%±3% for 6 hours. After being taken out, the insulation resistance (using a 500V megohmmeter) and insulation strength should be measured immediately without condensation. B2.8 Overload resistance test:
Short-term overload and impact tests should be carried out in an inductive circuit and in accordance with the provisions of B1.9. B2.9 Mechanical force resistance performance test:
The test sample should be vertically installed on the vibration test device and carried out in accordance with the provisions of B1.10. B2.10 Dustproof and antistatic test:
Should be carried out in a sealed box with a circulating air speed of not less than 5m/s for 15 minutes. The volume of the box should be 5 times the volume of the charging indicator. Before the test, pine pollen or fluorescent powder, quartz powder, etc. equivalent to 0.1% of the volume should be placed in the box. After the test, the powder on the surface of the shell should be removed and the shell should be opened. There should be no dust inside the meter.
When conducting the basic error test, wipe the indicator surface with a test cloth. The basic error after the test should be consistent with the basic error when the test cloth is not wiped.
B3 Inspection rules
B3.1 The inspection of the charging indicator is divided into factory inspection and type inspection. B3.2 Factory inspection includes the following test items: a) Basic error test;
b) Range and scale line inspection;
c) Rise and fall variation test;
d) Non-zero return test;
e) Dielectric strength test;
f) Dielectric resistance test;
g) Mechanical force resistance test.
B3.2.1 The number of random tests for factory inspection is 0.5% of the number of products in this batch, but not less than 3. If one item fails during the test, the unqualified item shall be double sampled for inspection. If it still fails, the batch of products shall be judged as unqualified. B3.3 Type inspection shall be carried out in the following circumstances: a) When the product has changed in structure, process or main materials, which affects the product performance; b) When the product is put into production again after being discontinued for a long time; c) When new products are being trial-formed;
d) When users have objections to product quality and make requests: e) Random inspection shall be carried out every 3 years.
B3.3.1Contents of type inspection:
All requirements of this appendix.
B3.3.2The number of random inspections for type inspection shall be no less than 3 products among the qualified products. If there are unqualified items, double sampling shall be conducted for the unqualified items. If the unqualified items are still unqualified, the product shall be deemed to have failed the type inspection. 95C. Therefore, when correcting the current capacity of the converter used in high altitude areas, the unfavorable factor that the current capacity decreases with the increase of altitude and the favorable factor that the ambient temperature decreases should be considered at the same time. 500
Altitude/m
B1 Technical requirements
B1.1 Basic error: ±10%.
MT68-2002
Appendix B
(Appendix to the standard)
Technical conditions for electromagnetic charging indicators
This technical condition is only applicable to the charging indicator of the mining lamp charging rack. B1.2 Range: 0~3A, 0~5A.
B1.3 Graduation lines: There should be no less than five graduation lines, which are 0A, 0.5A, 1A2A, 3A or 0A0.5A, 1A, 3A, 5A. B1.4 Rise and fall variation: It should be less than 1.5 times the absolute value of the basic error. B1.5 Non-zero return: less than 3mm.
B1.6 Insulation resistance: The insulation resistance between the terminal screw and the housing should not be less than 1MQ. B1.7 Insulation strength: It should be able to withstand a test of 0.5kV power frequency voltage for 1 minute between the terminal screw and the housing. B1.8 Constant damp heat: The performance of the charging indicator after the constant damp heat test should meet the requirements of B1.6 and B1.7. B1.9 Overload resistance: It should be able to withstand a current load of 120% of the rated value for 2h, and should be able to withstand 9 times the rated impact current (each time lasting 0.5s, the interval between each time is 1min, and a shock load lasting 5s). After the charging indicator that has undergone the load test cools to room temperature, its performance should meet the requirements of B1.1, B1.4, and B1.5. Note: It is allowed to adjust with a zero adjuster.
B1.10 Mechanical resistance performance: The charging indicator should be able to withstand a transportation shock test of 30m/s acceleration and 80~120 impacts per minute for 2h under the condition of transportation packaging. There should be no damage after the test and meet the requirements of B1.1, B1.4, B1.5, B1.6. B1.11 Dustproof and antistatic requirements for the case: Dust should not enter the inside of the case. When wiping the case, the indication value of the indicator pointer should not be affected by the static electricity of the case.
B2 Test method
B2.1 Basic error, lifting variation, non-zero return detection conditions: B2.1.1 The temperature of the charging indicator should be the same as the ambient temperature, and various tests should be carried out after preheating for 15min under rated load. B2.1.2 Various tests and comparisons should be carried out after the overload test and mechanical resistance performance test (the charging indicator reading is compared with the reading of the standard instrument).
B2.2 Basic error test:
From the test results obtained by steadily increasing and decreasing the measured value, take the maximum difference between the indicated value of the charging indicator and the actual value of the measured value (standard meter reading).
B2.3 Range and scale line inspection:
Visual inspection.
B2.4 Rising and falling variation test:
When the measured current value gradually increases and decreases, the tested charging indicator is steadily moved to a certain point on the scale line, and the maximum value of the actual difference between the two measurements is taken. bZxz.net
B2.5 Non-zero return test:
During the basic error test, when the charging indicator stays at the end division line of the effective range of the scale line, and then steadily decreases to zero (disconnect the line), read the non-zero value within 10s. B2.6 Insulation strength test:
Within 5 to 10 seconds, the voltage increases steadily from zero to 0.5kV and is maintained for 1 minute without insulation breakdown and flashover. 8
B2.7 Steady damp heat test:
MT68—2002
The test sample should be placed at (40±2)°C and relative humidity of 93%±3% for 6 hours. After being taken out, the insulation resistance (using a 500V megohmmeter) and insulation strength should be measured immediately without condensation. B2.8 Overload resistance test:
Short-term overload and impact tests should be carried out in an inductive circuit and in accordance with the provisions of B1.9. B2.9 Mechanical force resistance performance test:
The test sample should be vertically installed on the vibration test device and carried out in accordance with the provisions of B1.10. B2.10 Dustproof and antistatic test:
Should be carried out in a sealed box with a circulating air speed of not less than 5m/s for 15 minutes. The volume of the box should be 5 times the volume of the charging indicator. Before the test, pine pollen or fluorescent powder, quartz powder, etc. equivalent to 0.1% of the volume should be placed in the box. After the test, the powder on the surface of the shell should be removed and the shell should be opened. There should be no dust inside the meter.
When conducting the basic error test, wipe the indicator surface with a test cloth. The basic error after the test should be consistent with the basic error when the test cloth is not wiped.
B3 Inspection rules
B3.1 The inspection of the charging indicator is divided into factory inspection and type inspection. B3.2 Factory inspection includes the following test items: a) Basic error test;
b) Range and scale line inspection;
c) Rise and fall variation test;
d) Non-zero return test;
e) Dielectric strength test;
f) Dielectric resistance test;
g) Mechanical force resistance test.
B3.2.1 The number of random tests for factory inspection is 0.5% of the number of products in this batch, but not less than 3. If one item fails during the test, the unqualified item shall be double sampled for inspection. If it still fails, the batch of products shall be judged as unqualified. B3.3 Type inspection shall be carried out in the following circumstances: a) When the product has changed in structure, process or main materials, which affects the product performance; b) When the product is put into production again after being discontinued for a long time; c) When new products are being trial-formed;
d) When users have objections to product quality and make requests: e) Random inspection shall be carried out every 3 years.
B3.3.1Contents of type inspection:
All requirements of this appendix.
B3.3.2The number of random inspections for type inspection shall be no less than 3 products among the qualified products. If there are unqualified items, double sampling shall be conducted for the unqualified items. If the unqualified items are still unqualified, the product shall be deemed to have failed the type inspection. 94 Rising and falling variation test:
When the measured current value gradually increases and decreases, the tested charging indicator is smoothly moved to a certain point on the scale line, and the maximum value of the actual difference between the two measurements is taken.
B2.5 Non-return to zero test:
During the test of basic error, when the charging indicator stays at the end scale line of the effective range of the scale line, and then steadily decreases to zero (disconnect the line), the non-return to zero value is read within 10s. B2.6 Insulation strength test:
Within 5 to 10s, the voltage is steadily increased from zero to 0.5kV and maintained for 1min without insulation breakdown and flashover. 8
B2.7 Steady-state heat and humidity test:
MT68—2002
The test sample should be placed at (40±2)°C and relative humidity of 93%±3% for 6 hours. After being taken out, the insulation resistance (using a 500V megohmmeter) and insulation strength should be measured immediately without condensation. B2.8 Overload resistance test:
Short-term overload and impact tests should be carried out in an inductive circuit and in accordance with the provisions of B1.9. B2.9 Mechanical force resistance test:
The test sample should be installed vertically on the vibration test device and carried out in accordance with the provisions of B1.10. B2.10 Dust and antistatic test:
It should be carried out in a sealed box with a circulating air speed of not less than 5m/s for 15 minutes. The volume of the box should exceed the volume of the charging indicator by 5 times. Before the test, place pine pollen or fluorescent powder, quartz powder, etc. equivalent to 0.1% of the volume in the box. After the test, remove the powder on the surface of the shell and open the shell. There should be no dust inside the meter.
When conducting the basic error test, wipe the indicator surface with a test cloth. After the test, the basic error should be consistent with the basic error without wiping the test cloth.
B3 Inspection rules
B3.1 The inspection of the charging indicator is divided into factory inspection and type inspection. B3.2 Factory inspection includes the following test items: a) Basic error test;
b) Range and scale line inspection;
c) Rise and fall variation test;
d) Non-zero return test;
e) Dielectric strength test;
f) Insulation resistance test;
g) Mechanical force resistance performance test.
B3.2.1 The number of random inspections for factory inspection shall be 0.5% of the number of products in this batch, but not less than 3. If one item fails during the test, the unqualified item shall be doubled for inspection. If it still fails, the batch of products shall be judged as unqualified. B3.3 Type inspection shall be carried out in the following cases: a) When the product has changes in structure, process or main materials, which affects the product performance; b) When the product is put into production again after a long period of suspension; c) When a new product is trial-formed;
d) When the user has objections to the product quality and makes requirements: e) Random inspection shall be carried out every 3 years.
B3.3.1 Contents of type inspection:
All requirements of this appendix.
B3.3.2 The number of random inspections for type inspection shall be no less than 3 among the qualified products shipped out of the factory for inspection. If there is an unqualified item, the unqualified item shall be doubled for inspection. If it still fails, the product shall be considered to have failed the type inspection. 94 Rising and falling variation test:
When the measured current value gradually increases and decreases, the tested charging indicator is smoothly moved to a certain point on the scale line, and the maximum value of the actual difference between the two measurements is taken.
B2.5 Non-return to zero test:
During the test of basic error, when the charging indicator stays at the end scale line of the effective range of the scale line, and then steadily decreases to zero (disconnect the line), the non-return to zero value is read within 10s. B2.6 Insulation strength test:
Within 5 to 10s, the voltage is steadily increased from zero to 0.5kV and maintained for 1min without insulation breakdown and flashover. 8
B2.7 Steady-state heat and humidity test:
MT68—2002
The test sample should be placed at (40±2)°C and relative humidity of 93%±3% for 6 hours. After being taken out, the insulation resistance (using a 500V megohmmeter) and insulation strength should be measured immediately without condensation. B2.8 Overload resistance test:
Short-term overload and impact tests should be carried out in an inductive circuit and in accordance with the provisions of B1.9. B2.9 Mechanical force resistance test:
The test sample should be installed vertically on the vibration test device and carried out in accordance with the provisions of B1.10. B2.10 Dust and antistatic test:
It should be carried out in a sealed box with a circulating air speed of not less than 5m/s for 15 minutes. The volume of the box should exceed the volume of the charging indicator by 5 times. Before the test, place pine pollen or fluorescent powder, quartz powder, etc. equivalent to 0.1% of the volume in the box. After the test, remove the powder on the surface of the shell and open the shell. There should be no dust inside the meter.
When conducting the basic error test, wipe the indicator surface with a test cloth. After the test, the basic error should be consistent with the basic error without wiping the test cloth.
B3 Inspection rules
B3.1 The inspection of the charging indicator is divided into factory inspection and type inspection. B3.2 Factory inspection includes the following test items: a) Basic error test;
b) Range and scale line inspection;
c) Rise and fall variation test;
d) Non-zero return test;
e) Dielectric strength test;
f) Insulation resistance test;
g) Mechanical force resistance performance test.
B3.2.1 The number of random inspections for factory inspection shall be 0.5% of the number of products in this batch, but not less than 3. If one item fails during the test, the unqualified item shall be doubled for inspection. If it still fails, the batch of products shall be judged as unqualified. B3.3 Type inspection shall be carried out in the following cases: a) When the product has changes in structure, process or main materials, which affects the product performance; b) When the product is put into production again after a long period of suspension; c) When a new product is trial-formed;
d) When the user has objections to the product quality and makes requirements: e) Random inspection shall be carried out every 3 years.
B3.3.1 Contents of type inspection:
All requirements of this appendix.
B3.3.2 The number of random inspections for type inspection shall be no less than 3 among the qualified products shipped out of the factory for inspection. If there is an unqualified item, the unqualified item shall be doubled for inspection. If it still fails, the product shall be considered to have failed the type inspection. 9
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