Some standard content:
JB/T2294-1999
This standard is a revision of JB2294--78 "Axial Flow AC Exhaust Fan". Compared with the original standard, this standard mainly adds the preface, scope, reference standards and English name. The technical content of the standard is basically unchanged. Chapter 6 of this standard has been modified accordingly to make it meet the requirements of relevant standards. This standard replaces JB2294-78 from the date of implementation. This standard is proposed and managed by Guangzhou Electric Science Research Institute. This standard is drafted by Guangzhou Electric Science Research Institute. The main drafters of this standard are: Wang Qiongqi and Hua Guangpei. This standard was first issued in 1978
This standard is entrusted to Guangzhou Electric Science Research Institute for interpretation. 1 Scope
Machinery Industry Standard of the People's Republic of China
Axial AC Electric Ventilating Fans
Axial AC Electric Ventilating FansJB/T 2294-1999
Replaces JB2294-78
This standard applies to axial AC electric exhaust fans installed on walls for exhaust ventilation in industrial and similar environments. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, 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/T 755—1987
GB/T 1019—1989
GB/T 96511988
Basic technical requirements for rotating electrical machines
General rules for packaging of household appliances
Test methods for single-phase asynchronous motors
AC fans and speed regulators
GB/T 13380—1992
GB/T14806-1993AC ventilating fans for household and similar purposes and their speed regulators 3 Types, basic parameters and dimensions
3.1 Exhaust fans are divided into two types: FA and FTA according to the AC enclosed induction motor installed: a) FA is an axial flow exhaust fan driven by a single-phase capacitor-running motor; b) FTA is an axial flow exhaust fan driven by a three-phase induction motor. 3.2 The basic parameters and dimensions of the exhaust fan shall comply with the provisions of Table 1. Table 1
Rated voltage VbZxz.net
Rated frequency Hz
Blade diameter mm
Single phase 220
3.3 The installation dimensions, shaft extension diameter and length, blade fixing type and outer diameter of the wind frame stop (see Figure 1) of the exhaust fan shall comply with the provisions of Table 2.
Approved by the State Machinery Industry Bureau on August 6, 19992
Shaft extension length
2000-01-01 Implementation
4 Technical requirements
JB/T 2294-1999
Center circle diameter of mounting hole
4.1 The exhaust fan shall be able to operate reliably and continuously under the following conditions: a) The altitude shall not exceed 1000m;
b) The ambient temperature shall not exceed +40℃. Inch
Number of mounting holes × hole diameter
Outer diameter of wind frame stop
Not more than 430
Not more than 530
Not more than 630
Not more than 780
Note: When the altitude and cooling air temperature do not meet the requirements of (1, 2), the temperature rise limit of the exhaust fan shall be corrected with reference to GB/T755. 4.2 The minimum speed, minimum air volume and maximum input power of the exhaust fan at full speed at rated voltage and rated frequency shall comply with the requirements of Table 3.
Blade diameter
Synchronous speed
Minimum speed
Minimum air volume m/min
Number of motor phases
Maximum input power
Note: The maximum input power and power factor index of the aluminum wire motor shall be agreed upon by the manufacturer and the ordering parties. 4.3 The direction of the exhaust fan is set to rotate counterclockwise when viewed from the front of the fan blade. When the power supply voltage deviates from the rated value by no more than 10%, the exhaust fan should still be able to operate normally. 4.4
4.5 The starting performance of the exhaust fan should meet the following requirements: Under 85% of the rated voltage, the fan blade should be able to start at any position: When the 600
-single-phase exhaust fan reverses under the influence of the external air flow speed of 265m/min, it should be able to start against reverse within 2min after applying the rated voltage and operate normally.
4.6 When the exhaust fan is running at the rated voltage and rated frequency, the power factor of the motor shall not be lower than the provisions of Table 4. Table 4
Blade diameter
Synchronous speed
Power factor
Note: The power factor is allowed to have a tolerance of
1-co5, with a maximum of -0.07.
JB/T 2294-1999
4.7 When the three-phase power supply is balanced, the deviation between the no-load current of any phase of the three-phase exhaust fan and the average value of the three-phase no-load current at the rated voltage shall not be greater than 10% of the average value of the three-phase current. 4.8 The exhaust fan motor adopts E-class insulation material. When operating normally under the conditions specified in Article 4, the temperature rise of the motor winding should not exceed 65°C.
4.9 When the exhaust fan is in a stable thermal state, the insulation resistance of the motor winding to the casing shall not be less than 2M0. 4.10 The insulation of the exhaust fan motor winding to the casing shall be able to withstand a dielectric strength test lasting 1 minute without breakdown. The frequency of the test voltage is 50Hz, the waveform is an actual sine wave, and the voltage effective value is 1500V for single-phase and 1760V for three-phase. 4.11 The exhaust fan must have a grounding device with good contact. If there is no terminal board, the lead-out wire head should be welded with a wiring lug, and there should be a protective device between the lead-out wire and the casing. The lead-out wire should be selected from multi-strand soft wires with a cross-section of not less than 0.4mm2, and the length that can be connected to the power line, including the wiring lug, should not be less than 100mm.
4.12 After the exhaust fan is placed in a constant temperature and humidity chamber (room) at a temperature of 40±2℃ and a relative humidity of 95%±3% for 48 hours without condensation, its insulation performance should meet the following requirements: insulation resistance is not less than 2M;
--can withstand the AC test voltage value of single-phase 1000V and three-phase 1320V, and the withstand voltage test lasts for 1min without breakdown. 4.13 The exhaust fan runs at no load for 5min at 130% of the rated voltage, and the insulation between the plaques should not be broken down. 4.14 The fan blades of the exhaust fan should be able to withstand an overspeed test of 120% of the synchronous speed for 2min without damage or obvious deformation. 4.15 The capacitor of the single-phase capacitor-operated exhaust fan shall not be exposed. During the starting and operation process, the voltage at the capacitor terminal shall not exceed its working voltage.
4.16 The noise of the exhaust fan shall be minimized. The noise level of the low-noise exhaust fan with A weighting shall not be greater than the provisions of Table 5. Table 5
Blade diameter mm
Synchronous speed T/min
Noise level AdB
4.17 The bearings of the exhaust fan shall continue to be used normally after 5000h of continuous operation. 4.18 The rotating part of the exhaust fan must be well balanced and there shall be no obvious vibration during operation. 600
4.19 All metal shell surfaces of the exhaust fan shall have an anti-corrosion protective layer, and the surface paint layer shall not have obvious spots, wrinkles, bubbles, cracks, damage and adherent dirt to ensure a good appearance and not easy to corrode and rust. 4.20 The blades of the exhaust fan shall be produced according to the national unified (or industry-approved) blade shape and size. 4.21 Provided that the user complies with the storage and use rules of the exhaust fan, if the exhaust fan is damaged or fails to work due to poor manufacturing quality within one year from the date of sale, the manufacturer shall be responsible for repairing or replacing parts or products for the user free of charge. 5 Test methods and acceptance rules
5.1 The selection of test measuring instruments shall comply with the following provisions: 一一The accuracy of electrical measuring instruments used for type tests shall not be lower than Class 0.5, and that for factory tests shall not be lower than Class 1.0; the impeller anemometer used for wind speed measurement shall have a nominal diameter of 70~100mm and a wind speed range of 30~5001m per minute. All anemometers shall be calibrated annually with a Pitot tube and a compensated micromanometer; 一一The instrument for measuring the speed shall have no obvious effect on the exhaust fan speed. 4
5.2 Determination of air volume
5.2.1 Test conditions:
JB/T 2294-1999
a) The test should be carried out indoors without the influence of external airflow: b) The test air cylinder consists of a ventilation duct with a square cross-section and a bell-shaped mouth on its air inlet side (referred to as square air cylinder). Its dimensions are shown in d
Figure 2 (D is the diameter of the exhaust fan blade under test). The radial edge width of the bell-shaped mouth at the air inlet end is 6
The baffle on which the exhaust fan is installed should be tightly connected to the air cylinder and should not leak; the inner surface of the square air duct must be flat and smooth. c) The lower edge of the bell mouth of the square air bell shall not be less than 0.5m from the ground, and the upper edge shall not be less than 1.8m from the roof. The distance between the two sides of the ventilation duct and the air inlet shall not be less than 3D from the obstacles, and the distance between the air outlet and the obstacles shall not be less than 5D: d) The anemometer impeller plane is placed on the measuring plane at a distance from the bell mouth and the connection point of the ventilation duct, and its axis is ensured to be parallel to the axis of the exhaust fan blade; e) Divide the cross section of the ventilation duct into equal small squares according to the number of measuring points specified in Table 6 (see Figure 3), and place the axis of the anemometer impeller at the center of each small square to measure the wind speed. Table 6
Blade diameter mm
Number of measuring points
Measurement balance
Airflow direction
Square wind box
Anemometer is placed at the center of each small
square
Figure 3 Anemometer placement
Number of sections on each side of the ventilation duct n
5.2.2 Test procedure:
JB/T 2294-1999
a) Install the exhaust fan in the center of the baffle at the outlet end of the square duct; b) Before the test, run the exhaust fan at rated voltage and rated frequency for at least 1 hour, and then measure its input power and speed. During the test, the voltage variation range should not exceed ±1% of the rated voltage, but the input power must be read at the rated voltage value; c) Place anemometers at the measuring points shown in Figure 3 to measure the wind speed at the center of each small block in turn. Divide the anemometer indication by the time required for speed measurement to obtain the desired wind speed (m/min). The measurement should be at least 1 minute. Each reading of the anemometer should be corrected according to the calibration curve of the anemometer;
d) Determination of air volume. The arithmetic mean of the wind speed at the center of all small blocks is the average air flow speed (m/min) through the ventilation duct. Multiplying the average wind speed by the cross-sectional area (m2) of the ventilation duct is the total air volume (im/min.) to be measured. 5.3 Starting test:
--Starting at 85% rated voltage: Install the exhaust fan axis horizontally on the test frame, first slowly increase the voltage until the fan blades rotate slightly, then stop increasing the voltage, and continue to slowly increase the voltage after the fan blades stop rotating. After finding the starting position of the fan blades that require the highest voltage, apply 85% rated voltage at this position, and the fan blades should be able to operate normally. -- Anti-reverse starting: Install the exhaust fan axis horizontally on the test frame, and use an exhaust fan with sufficient wind power as the external reverse wind source. Adjust the distance between it and the exhaust fan under test (to ensure that the planes of the two blades are parallel), so that the average wind speed at the plane of the blade of the exhaust fan under test (at least the center of the horizontal center line and the blade end) is 265m/min, and the exhaust fan is reversed. After applying the rated voltage to it, it should be able to ensure that it can start anti-reverse and operate normally within 2 minutes. 5.4 Temperature rise test: When the exhaust fan is applied with rated voltage and rated frequency under free exhaust and reaches a stable state, it shall be carried out according to GB/T9651.
5.5 Insulation resistance measurement: Immediately after the temperature rise test, use a 500V DC megohmmeter to measure the insulation resistance of the winding to the housing. The factory test is allowed to be carried out in a cold state.
5.6 Withstand voltage test: The tested part is the same as the insulation resistance measurement part. The capacity of the test transformer used should not be less than 0.5kva. The withstand voltage test is carried out immediately after the insulation resistance measurement. The applied voltage should not be greater than half of the specified test voltage at the beginning, and then gradually increased to the full value. The full value test voltage lasts for 1 minute, and then reduced to less than half of the test voltage to disconnect the power supply. For single-phase capacitor-operated motors, it is allowed to disassemble the capacitor for this test.
5.7 Moisture-proof test: Place the exhaust fan in a constant temperature and humidity chamber (room) that complies with the provisions of Article 15 (before placing it, the temperature of the exhaust fan should be ensured not to be lower than the temperature of the chamber (room) to avoid condensation on the sample surface due to temperature difference after placing it). After 48 hours without condensation, conduct insulation performance test in the chamber (room) in the following order (the tested parts are the same as Article 29): 1. Use a DC 500V megohmmeter to measure the insulation resistance: Conduct a withstand voltage test.
5.8 Overspeed test: Use a variable frequency power supply or mechanical speed control method to make the exhaust fan blades reach 120% of the synchronous speed for 2 minutes. 5.9 The input power, load current, power factor and no-load current of the exhaust fan shall be tested in accordance with GB/T9651 (the exhaust fan shall be in a free exhaust state during the load test). 5.10 Noise test: Use a sound level meter qualified by the metrology department to measure the noise of the exhaust fan under the following conditions: 1. The exhaust fan should be installed on a mounting frame that does not generate any additional vibration; when operating at rated voltage and rated frequency, the noise is measured at the three points shown in Figure 4 through a microphone; 6
JB/T 2294-1999
1. The arithmetic mean of the A-weighted network measured values at the three points is taken as the assessment noise level of the exhaust fan; the test should be carried out in an anechoic room. If there is no anechoic room, it should be carried out under conditions that are at least 8dB lower than the exhaust fan noise level and the influence of the surrounding reflectors should make the multiplication attenuation not less than 4dB. 5.11 Each exhaust fan must be inspected and qualified by the technical inspection department of the manufacturer before it can leave the factory. 5.12 Factory test:
a) Appearance inspection: surface paint, electroplating, grounding device, nameplate and mark, bearing operation; b) Dimension inspection: installation size, shaft extension size, fan blade size; c) Winding insulation resistance;
d) Starting at 85% rated voltage;
e) Load current and input power;
f) Deviation of three-phase no-load current;
g) Turn-to-turn insulation test;
h) Withstand voltage test.
5.13 Type test
5.13.1 Type test shall be carried out in one of the following situations: a) Trial production of new products;
b) When there are major changes in design, process or materials used; ) When products that are not frequently produced are produced again; d) Regular sampling of batch or mass-produced products, at least once a year. 5.13.2 Type test shall be carried out according to all items of technical requirements. 5.13.3 Products that have undergone type testing cannot be delivered as normal finished products. 5.13.4 The number of type tested products shall not be less than 3 units. If any unqualified products are found among the products sampled, the number of products sampled for this item shall be doubled. If they are still unqualified, the batch of products shall be considered unqualified and shall not be shipped until the defects are eliminated. 5.14 The ordering party has the right to check whether the quality of the product meets the requirements of this standard. 6 Marking, packaging, transportation and storage
6.1 Marking
JB/T 2294--1999
6.1.1 The product should have a durable nameplate and indicate the following items: a) product name, model and specifications;
b) rated voltage, V;
c) rated frequency, Hz;
d) rated total input power, W;
e) nominal air volume, m°/min;
f) noise sound power level, dB (A);
g) manufacturer's name.
6.1.2 The product should have a production date or production number mark (it is allowed to mark it separately on the product). 6.1.3 Trademark mark
Brand number handled in accordance with the prescribed procedures.
6.1.4 Instruction Manual
The instruction manual attached to the product shall at least include the following information and instructions: a) Product use location;
b) Product installation height, power supply mode and installation method; c) Electrical schematic diagram or wiring diagram;
d) Manufacturer’s name and address.
6.1.5 Packing box markings
a) Product name, model, specification;
b) Brand or trademark;
|) Product quantity (single package may not have quantity marked); d) Gross weight of packing box, kg;
e) Packing box dimensions: length × width × height (cm): f Full name of manufacturer:
g) Date of manufacture (or number) or production batch number; h) Precautions markings: “Handle with care”, “Do not get wet”, “Upward” and other words or symbols. 6.2 Packaging
6.2.1 The packing box should contain:
a) a complete set of exhaust fans;
b) product certificate;
c) packing list (if there are accessories and spare parts); d) instruction manual.
6.2.2 The motor shaft of the exhaust fan should be oil sealed when it is packed. 6.2.3 If the ordering party makes a request, the manufacturer shall provide the following additional information: 8
a) Power factor:
b) Speed, r/min;
c) Impeller diameter, mm;
d) Number of blades;
e) Speed regulator type and number of gears;
f) Insulation grade;
g) Air performance curve of exhaust fan;
h) Bearing type and lubrication method.
6.2.4 Drop test
JB/T 2294—1999
6.2.4.1 The drop test of this standard shall be in accordance with Chapter 4 of Appendix A of GB/T1019-1989. Test strength Drop test shall be conducted on the packaged product according to circulation condition 2.
6.2.4.2 The drop test results shall comply with the requirements of 4.2.4.2 of GB/T10191989. 6.3 Transportation
Avoid collision and rain and snow during transportation. 6.4 Storage
The exhaust fan should be stored in a well-ventilated warehouse without opening the package. There should be no corrosive gas around it. 9
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