1、 ICS 29.160.01 K 20 National Standard of the Peoples Republic of China GB 14711-2006 Substitute for GB 14711-1993 Safety Requirements of Small and Medium Size Rotating Electrical Machines Issued on August 25, 2006 Effective from March 1, 2007 Issued by General Administration of Quality Supervision,
2、Inspection and Quarantine of the P. R. China Standardization Administration of the Peoples Republic of ChinaGB 14711-2006 I Contents Foreword III 1 Scope. 1 2 Normative sources of standards. 1 3 Technical terms and explanations 2 4 General requirements. 2 5 Structure. 2 6 Symbols 6 7 Tests 7 8 Low v
3、oltage (rated voltage1, 000V)AC motor (including universal motor)12 9 High voltage (rated voltage1, 000V) AC motor.13 10 DC motor13 11 Portable and auxiliary generator.14 12 Variable-frequency 2. The safety requirements of portable, auxiliary, and variable-frequency 3. Tables related were placed at
4、the back of this book, for easy reference. The standard is proposed by China Electrical Equipment Industry Association. The preparation and management of standard is under the supervision of the China Rotating Electrical Machine Standardization or damaged insulation; or loose connections; or aged fl
5、exible components and outer cover parts. 5 Structure 5.1 General principles 5.1.1 The electrical components of motor are specially approved models and specifications. They should be tested along with the motor. All rotating parts should operate safely (including at over-speed). Components that are n
6、ot connected to rotating parts and would not affect electrical or mechanical safety may be taken as a separate part of the motor, and can be supplied separately. 5.1.2 With the exception of waterproof motors (e.g. motors for underwater use) and those free of water accumulation inside, all motors sho
7、uld have appropriate dewatering measures to prevent accumulated water inside, which would reduce the clearance and creepage distance between windings/naked charged parts and ground. The air vents on the motor can also perform dewatering functions. When arranging water-discharge holes, their diameter
8、s should be no smaller than 3mm and conform to the requirements of 7.6. 5.1.3 If motor is an integral part of other equipment, the functions of motor bedplate and outer cover (inclusive of junction box) can be performed by the equipment. GB 14711-2006 3 5.1.4 As to natural air-cooling motor, if buil
9、t-in overheat protector is required, it should conform to GB/T 13002. 5.1.5 With the exception of open-type motors, it must be ensured that contact with the panel or covering of naked charged parts (AC30V , DC50V) is avoided. The panel or covering may only be opened with tool or keys. 5.2 Outer cove
10、r 5.2.1 The materials of any component on the outer cover should be able to endure high temperatures and mechanical stress that may occur during normal working conditions, and should not incur fire or electric shock due to bending, creep, or deformation. 5.2.2 Outer cover protection grading should c
11、onform to GB/T 4942.1-2001. 5.3 Non-metallic structures 5.3.1 Insulation structures for supporting and fixing current-carrying components should have good resistance to inflammation, heat, electric tracking, moisture, and adequate dielectric strength and mechanical strength. 5.3.2 Non-metallic outer
12、 cover, windshield, and junction box should be able to endure humidity, grease, inflammation, and temperature variation. They should be able to withstand the impact test as in 7.8.3, the ageing test as in 7.11, the heat deformation test as in 7.12, and the burning test as in 7.13. 5.3.3 The patch bo
13、ard and non-metallic junction box should be able to endure the temperatures no lower than that specified in Table 1. 5.4 Junction box (for motors 750V) and wiring devices 5.4.1 Junction box can be an independent component fixed on the exterior of motor, or serve, partially or wholly, as a part on th
14、e motor housing. 5.4.2 Junction box should have appropriate volume in order to contain wiring devices, meeting the clearance and creepage distance requirements of 5.8, and be able to withstand the impulse voltage test as in 7.5.2. 5.4.3 If made from metal, the junction box should have the thickness
15、as specified in Table 2, and conform to the test requirements of 7.8.4. 5.4.4 Non-metallic junction box should conform to 5.3.2. 5.4.5 The fixing between junction box and motor housing should be separate from the fixing between junction box and its cover. 5.4.6 The protection grade of junction box o
16、n small motor should be no less than IP44. 5.4.7 If wire conduit is used, it should be: a) No smaller than the sizes specified in Table 3, in consistence with the rated current marked on the motor; b) Placed in a flat, large enough area, to meet the requirements of bushing and locknut, unless the op
17、ening on the junction box is suitable for wire to pass through and bushing need not be used to protect wire insulation. 5.5 Conduit bushing and equivalent tapped hole 5.5.1 Straight pipe or Taper pipe thread seal can be used for the tapped hole of conduit, with the screwing length no smaller than 3.
18、5 pitches. The number of inlet tapped-hole should be specified in product standard description. The inlet holes should be equipped with insulation conduit and be sealed with rubber or similar material at the factory. 5.5.2 Conduit bushing for a separately-cast junction box and tapped hole for fixing
19、 rigid metal conduit should have enough mechanical strength and be tested as per 7.8.5. 5.6 Supply cord 5.6.1 If the motor is equipped with supply cord, or for the purpose of easy connection to other equipment, flexible cables that extend outside the bedplate (housing) are supplied along with necess
20、ary plugs, the cord and plugs should conform to product standard or relevant standard of the equipment. 5.6.2 Unless grounding is not required, there should be one earth lead among the cords. The earth lead (including the terminal) should bear a different color or symbol for easy distinction. 5.6.3
21、The supply cord should have a rated voltage no smaller than the motors maximum working voltage. Its current-carrying capacity should at least be equal to load current multiplied by usage coefficient or full load rated current multiplied by 125%, whichever is the greater. The insulation of cord shoul
22、d be able to withstand the power-frequency voltage test related to this circuit. 5.6.4 Unless there are measures to eliminate the possible tensile force or the supply cord is not exposed, insulation layer and clamps should be available where the cord extends out, in order to prevent external force p
23、assing onto the wires inside and avoid twisting or displacement of cords. 5.6.5 Unless there are other protective measures, it must be ensured that cords do not withdraw into the motor. 5.6.6 Clamps: cord clamps should be made of insulating material. If metal is present, there should be insulating l
24、ining. GB 14711-2006 4 5.6.7 Cord clamps should be examined for reliability and be able to withstand the tension and torsion tests as in 7.9. 5.6.8 Cord should not be forced through the inlet opening so as to damage the insulation. 5.6.9 The loose cables/cords in the junction box that are to be conn
25、ected on site should be no shorter than 150mm in free length. 5.7 Lead wire 5.7.1 Lead wire types and sizes Lead wire should have appropriate current-carrying capacity and length. Lead wires on coils or of similar purpose should conform to the following requirements: a) The lead wire for connecting
26、to power supply should be no smaller than 0.75mm 2in cross-sectional area; b) The lead wires inside the motor, such as those which connect to internal components or power supply cords or patch board, can be smaller than 0.75mm 2but should be no smaller than 0.30mm 2 . 5.7.2 Lead wire insulation 5.7.
27、2.1 As for windings lead or brush holder lead, which is soft and cannot be positioned to ensure proper clearance, insulated conductor should be used or thermal- and moisture-resistant material should be used to wrap up continuously between two support points. The material can be insulating pad, insu
28、lating hose or other appropriate means. 5.7.2.2 The models and specifications of lead should fit the working voltage of motor. If instantaneous high tension may occur on any component during normal operation, the lead should have good insulating capability towards the high tension. 5.7.2.3 Lead shou
29、ld conform to relevant standard, with thermal withstanding grade no less than the insulation grade of the motor. 5.7.3 Lead protection 5.7.3.1 Internal lead (wire) should be properly fixed with windings. Two or more leads (wires) of the same alignment should be bound together. It should not be place
30、d on the pointed or sharp edge of parts and stay away from movable parts. 5.7.3.2 The connections of internal leads (wire) should be insulated with bushings and tapes and properly fixed, to prevent accident due to loose bushing or loose weld. The connections should be able to withstand the dielectri
31、c test as specified in 7.5. Lead (wire) and wire terminal should be joined with cold weld. 5.7.3.3 Proper measures should be available to ensure wire terminals stay in their original position when connector bolts/nuts come loose. Open connector and lock washer should not be the only means. 5.7.3.4 W
32、hen stranded- lead (wire) is connected to terminal, it should stay in certain position, to avoid grounding or short circuit. 5.7.3.5 When internal lead (wire) goes through motor bedplate, insulators or other means should be used to ensure insulation at the bores. Insulators should be smooth, without
33、 burrs or sharp edge. Lead that passes through the external cooling chamber of hermetic motor should be protected with metallic cable conduit or similar pipes. 5.8 Clearance and creepage distance of low voltage motors (for requirements on high voltage motors, see Chapter 9 of this standard) 5.8.1 Th
34、e clearance and creepage distance as described below should be no smaller than that specified in Table 4. Otherwise, they should conform to 5.8.25.8.5. a) Along the insulation material surface and through the air; b) Between naked charged parts of different voltages or between different polarity; c)
35、 Between naked charged parts (including electromagnetic wire) and parts that are grounded (or may be grounded). 5.8.2 With the exception of low voltage motors, clearance and creepage distance should conform to relevant articles in this standard. 5.8.3 As far as the stationary parts (e.g. brush holde
36、r) of brushed motors are concerned, due to carbon soot accumulated (eg. on the insulation of the bush holder) between commutator and slip ring, the clearance and creepage distance should be greater than that specified in Table 4 by 50% at least. Otherwise, appropriate spacers, rings or similar devic
37、es should be provided. 5.8.4 The requirement of 5.8.3 on increased clearance and creepage distance is not applicable to motors with frame size greater than H90. 5.8.5 As to the rotor windings and centrifugal switches of wound-rotor motors, the clearance and creepage distance may be smaller than that
38、 specified in Table 4, but it must be ensured that no bad consequence would occur. 5.8.6 It must be ensured that wire connectors, including pressure-type connection (quick connection), do not twist or move, in order to keep clearance and creepage distance no smaller than that specified in 5.8.1. Unless clearance and creepage distance remain unchanged when connectors deviate in a range of 30, or the connector screws are insulated, it is not necessary to take additional measures to prevent connector turning.
