This standard specifies the safety requirements and test methods for industrial or commercial clothes dryers (hereinafter referred to as industrial clothes dryers). This standard applies to industrial clothes dryers and dry cabinets (boxes) with a rated dry fabric capacity of 6 kg to 200 kg. JB 6238-1992 Safety requirements for industrial clothes dryers JB6238-1992 Standard download decompression password: www.bzxz.net

Subject content and scope of application
Machinery Industry Standard of the People's Republic of China
Safety requirements for industrial clothes dryers
JB 6238-92
This standard specifies the safety requirements and test methods for industrial or commercial clothes dryers (hereinafter referred to as industrial clothes dryers). This standard applies to industrial clothes dryers and drying cabinets (boxes) with a rated dry fabric capacity of 6kg to 200kg. 2 Reference standards
GB 4706.1
3 Safety requirements
3.1 Starting performance
Basic technical requirements for motors
General safety requirements for household and similar electrical appliances Basic environmental test procedures for electrical and electronic products Test Ca: Steady damp heat test method Industrial clothes dryers should be tested under rated load according to the method specified in Article 4.3 and should be able to start smoothly. 3.2 Temperature rise
Industrial clothes dryers should be measured under rated conditions according to the method specified in Article 4.4. When testing at an altitude below 1000m, the winding temperature rise of the drive motor and fan motor should not exceed the requirements of Table 1. Table
Measurement location
Windings of driving motors and fan motors
3.3 Leakage current
E-level insulation
B-level insulation
Measurement method
Resistance method
The leakage current of industrial clothes dryers shall be measured according to the method specified in Article 4.5. Its value shall not be greater than that specified in Table 2 and Table 22.
Heating form
Steam heating type
Electric heating type
3.4 ​​Hot insulation resistance
6~~10 kg
>10~200 kg
Leakage current
The hot insulation resistance of industrial clothes dryers shall be measured according to the method specified in Article 4.6. Its value shall not be less than 2MQ. 3.5 Hot electrical strength
The hot electrical strength of industrial clothes dryers shall be tested in accordance with the method specified in Article 4.7. During the test, flashover and breakdown shall not occur. The test voltage value is specified as follows:
3.5.1 For motors and various electrical appliances with a single-phase rated voltage of 220V or less, the test voltage is 1500V. Ministry of Machinery and Electronics Industry approved 60
993-0101 on June 16, 1992 for implementation
JB 6238--92
3.5.2 For motors and various electrical appliances with a three-phase rated voltage of 380V, the test voltage is 1760V. 3.6 Insulation resistance and electrical strength under damp heat conditions
The damp heat test of industrial clothes dryers shall be conducted in accordance with the method specified in Article 4.8. The insulation resistance and electrical strength are specified as follows: The insulation resistance value under damp heat conditions shall not be less than 2MQ; no flashover or breakdown shall occur during the damp heat electrical strength test. The test voltage value is: 1250V for single phase; 1460V for three phase. Note: When electronic components are connected with the main electrical components, in order to avoid damage during the insulation resistance and electrical strength tests, as long as these electronic components meet the requirements of the relevant standards, they can be disconnected and the whole machine shall be subjected to the two tests. 3.7 Grounding protection performance
3.7.1 The grounding terminal must be provided at a visible location on the outer surface of the casing of the industrial clothes dryer, and there must be an obvious and durable grounding protection symbol Ji. 3.7.2 The screws and nuts of the grounding terminal of the industrial clothes dryer must be made of brass or copper alloy. It shall not be used for other purposes. The nominal thread diameter of the screw shall be selected in accordance with Table 3. Table 3
Rated current
Nominal thread diameter
3.7.3 The grounding protection performance of industrial clothes dryers shall be measured according to the method specified in Article 4.9, and the grounding resistance value shall not be greater than 0.1Q. 3.7.4 The insulation surface color of the grounding wire shall be yellow-green double-color wire. 3.8 Power cord
3.8.1 The nominal cross-sectional area of ​​the power cord of the industrial clothes dryer shall not be less than the values ​​listed in Table 4. Table 4
>6~10
>10~16
>16~25
>25~32
>32~40
>40~63
Nominal cross-sectional area of ​​the wire
3.8.2 The power cord shall be protected by an insulating sleeve at the entrance of the casing to prevent damage and shall be securely fixed.
3.9 The internal wiring of industrial dryers should avoid the influence of heat sources and prevent mechanical damage. The wiring should be firm and reliable to prevent fire. 3.10 The fabric feeding door of the industrial dryer should have a reliable interlocking device, and the power supply should be automatically cut off when the door is opened 50mm. 3.11 The industrial dryer should have reliable overheating and overload protection devices. 3.12 The steam pipe system of the steam-heated industrial dryer should not leak. 3.13 The industrial dryer should not cause fire, electric shock and harm to the human body when it is misoperated. 3.14 The exposed live and rotating parts of the industrial dryer should be equipped with protective covers with a certain rigidity to prevent personal injury accidents. 3.15 Abnormal operation
The industrial dryer shall be tested according to the method specified in Article 4.10. After the test, the fabric does not turn yellow and it shall not cause fire. 61
4 Test method
4.1 Test conditions
JB6238-92
4.1.1 The test environment should be free of strong external electricity, magnetic field interference and harmful gases. 4.1.2 When testing on site, the test machine should be more than 3m away from the wall or placed in an open outdoor place with a flat and hard ground. 4.1.3 When testing in an open outdoor place, the wind speed should not exceed 3m/s. 4.1.4 For steam-heated industrial dryers, the steam pressure should be within the range of 0.4~0.6MPa. 4.2 Accuracy of test instruments and meters
Voltmeter 0.5 level
Three-phase watt-hour meter 2.0 level
Mgohmmeter DC 00V 1.0 level
Thermometer glass rod type 0～100±0.5℃
Timer 0.5s
TGT--100 scale 0～100kg sensitivity 50g
Single-arm bridge ±0.2%
Leakage current meter <2.3%bzxZ.net
Ground resistance meter 0.5 level
Withstand voltage test device 5%
4.3 Starting performance test
Under rated load, apply 0.85 rated voltage to the industrial dryer, change the position of the motor rotor and drum arbitrarily, start three times, and the whole machine should be in a stopped state before each start. 4.4 Temperature rise test
First use a single-arm bridge to measure the cold resistance of the drive motor and fan motor windings, and record the ambient temperature. The industrial dryer is operated continuously under rated conditions according to the working program time set by the program controller. When the temperature rise of the drive motor and fan motor windings reaches stability, use a single-arm bridge to measure the hot resistance of the two motor windings within 20s, record the ambient temperature, and then calculate the temperature rise value of the two motors according to the following formula.
Calculation of temperature rise of the drive motor or fan motor:, or t.=RRR(235 + t)-(ct)
Temperature rise value of the drive motor, K;
Where: t——!
Temperature rise value of fan motor, K;
R--cold resistance value of drive motor and fan motor winding,; R,-hot resistance value of drive motor and fan motor winding,; ti--ambient temperature when measuring cold resistance value, ℃; t.-ambient temperature when measuring hot resistance value, ℃. 4.5 Determination of leakage current
After the temperature rise test in 4.4, pad the industrial dryer and voltage regulator with dry insulating material with a thickness of not less than 10mm, and close the Sa1, Sa2 and Sa: switches according to the circuit in Figure 1. Make it operate normally, increase the input voltage to 1.1 times the rated value, and open the Sa1, Saz, Sas switches in turn, and close the other two switches, and measure the average leakage current of the exposed non-live metal parts of the industrial dryer and the live parts of each phase, and take the maximum value as the leakage current value of the machine. 62
4.6 Determination of hot insulation resistance
JB6238—92
G-industrial clothes dryer, M-three-phase motor, mA leakage current meter; Sai, Saz, Sas---single-pole switch in each phase circuit. Immediately after the leakage current is measured, use a 500V DC megohmmeter to measure the hot insulation resistance between the live parts and the exposed non-live metal parts of the industrial clothes dryer.
4.7 Hot electrical strength test
After the hot insulation resistance is measured in 4.6, immediately use a withstand voltage test device to apply a basic sinusoidal wave frequency of 50Hz to the live parts and the exposed non-live metal parts of the industrial clothes dryer. The test voltage value is in accordance with the provisions of 3.5 and the test lasts for 1 minute. 4.8 Wet and hot insulation resistance and electrical strength test A complete set of main electrical accessories, such as drive motor, fan motor, temperature control system, electric heater, timer or program controller, are simulated as industrial dryers and tested for 48 hours in accordance with GB2423.3. After the test, it should meet the requirements of Article 3.6. 4.9 Determination of grounding protection performance
Between the grounding terminal and the exposed non-live metal part of the industrial dryer, a grounding resistance meter is used to apply 12V, 25A AC. The reading on the instrument is the grounding resistance value of the machine. 4.10 Abnormal operation test
Under the rated state, the dryer drum of the industrial dryer does not run, but it is still heated. Under the condition that the voltage of the electric heating power supply is 0.85 of the rated value, the fan motor is still running. The test ends after continuous operation for 0.5h or the over-temperature protector is tripped. After the test, it should meet the requirements of Article 3.14. Additional Notes:
This standard was proposed and managed by the Guangzhou Electric Appliance Research Institute of the Ministry of Machinery and Electronics Industry. This standard was drafted by the Guangzhou Daily Appliance Research Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard were Sun Xianglin and Shen Zongru.
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