Safety requirements of small power motors
1 Scope
This standard specifies the general safety requirements of small power motors.
This standard is applicable to the small power motors specified in GB/T 5171.1 (hereinafter referred to as “motors”), and other similar motors also may be implemented by making reference thereto.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 755 Rotating electrical machines - Rating and performance
GB/T 1971 Rotating electrical machines - Terminal markings and direction of rotation
GB/T 2423.3 Environmental testing - Part 2: Testing method - Test Cab: Damp heat, steady state
GB/T 2423.4 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle)
GB/T 2423.55 Environmental testing for electric and electronic products - Part 2: Test methods - Test Eh: Hammer tests
GB/T 2900.25 Electrotechnical terminology - Rotating electrical machines
GB/T 2900.27 Electrotechnical terminology - Small-power motor
GB/T 3667.1-2016 AC motor capacitors - Part 1: General - Performance, testing and rating - Safety requirements - Guide for installation and operation
GB/T 3667.2-2016 AC motor capacitors - Part 2: Motor start capacitors
GB/T 4207 Method for the determination of the proof and the comparative tracking indices of solid insulating materials
GB 4343.1 Electromagnetic compatibility requirements for household appliances, electric tools and similar apparatus - Part 1: Emission
GB 4706.1 Household and similar electrical appliances - Safety - Part 1: General requirements
GB/T 4942 Degrees of protection provided by the integral design of rotating electrical machines (IP code) - Classification
GB/T 5169.5 Fire hazard testing for electric and electronic products - Part 5: Test flames - Needle test method - Apparatus confirmatory arrangement and guidance
GB/T 5169.11 Fire hazard testing for electric and electronic products - Part 11: Glowing/hot-wire based test methods - Glow-wire flammability test method for end-products (GWEPT)
GB/T 5169.16 Fire hazard testing for electric and electronic products - Part 16: Test flames - 50 W horizontal and vertical flame test methods
GB/T 5169.21 Fire hazard testing for electric and electronic products - Part 21: Abnormal heat - Ball pressure test method
GB/T 5171.1 Small power motors - Part 1: General technical requirements
GB/T 5171.21 Small power motors - Part 21: General test methods
GB/T 5171.22 Small-power motors - Part 22: Test methods for permanent magnet brushless DC motors
GB/T 9651 Test procedures for single-phase induction motor
GB/T 9816.1-2013 Thermal-links - Part 1: Requirements and application guide
GB/T 12113-2003 Methods of measurement of touch current and protective conductor current
GB/T 12665 Requirements of damp-heat testing of electrical machine for service in general environmental condition
GB/T 14536.1 Automatic electrical controls for household and similar use - Part 1: General requirements
GB/T 14536.3-2008 Automatic electrical controls for household and similar use - Particular requirements for thermal motor protectors
GB/T 16842 Protection of persons and equipment by enclosures - Probe for verification
GB/T 17626.2 Electromagnetic compatibility - Testing and measurement techniques - Electrostatic discharge immunity test
GB/T 17626.4 Electromagnetic compatibility - Testing and measurement techniques - Electrical fast transient/burst immunity test
GB/T 17626.5 Electromagnetic compatibility - Testing and measurement techniques - Surge immunity test
GB/T 17948.1 Rotating electrical machines - Functional evaluation of insulation systems - Test procedures for wire-wound windings - Thermal evaluation and classification
GB/T 17948.2 Functional evaluation of insulation systems for rotating electrical machines - Test procedures for wire-wound windings - Classification of changes and insulation component substitutions
JB/T 6742 The commutator of small power motors
JB/T 9547-2011 Specification for centrifugal starting switch use of single-phase motor
JB/T 13609 Specification for electronic starting switcher used for single-phase motors
IEC 60384-14: 2016 Fixed capacitors for use in electronic equipment - Part 14: Sectional specification - Fixed capacitors for electromagnetic interference suppression and connection to the supply mains
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2900.25, GB/T 2900.27, GB 4706.1 and GB/T 5171.1, as well as the following, apply.
3.1
creepage distance
minimum path distance along the surface of insulating material between two conductive parts or between a conductive part and the accessible surface
3.2
clearance
minimum spatial distance between two conductive parts or between a conductive part and the accessible surface
3.3
enclosure
accessible motor surface, including the surface of such parts as motor junction boxes, but excluding accessible parts
3.4
component
special accessories for motor
Example: centrifugal switch, capacitor, thermal protector, etc.
3.5
insulator
part used to insulate and support a conductor
3.6
diameter of motor
diameter measured on the excircle of the motor stator housing, but excluding the dimensions of radiation rib, junction box and welding seam of the motor
3.7
pollution degree
numeral characterization of the expected pollution degree of the micro-environment
Note: Pollution degree 1: No pollution, or only dry non-conductive pollution exists, which has no effect.
Pollution degree 2: Normally only non-conductive pollution occurs. Occasional temporary conductive pollution caused by condensation must be expected.
Pollution degree 3: Conductive pollution or dry non-conductive pollution that becomes conductive due to condensation occurs.
Pollution degree 4: Persistent conductive pollution is caused, for instance, by conductive dust or by rain or snow.
3.8
basic insulation
insulation applied to live parts to provide basic protection against electric shock
3.9
supplementary insulation
independent insulation other than basic insulation, which is applied to protect against electric shock in case of failure of basic insulation
3.10
double insulation
insulation system consisting of basic insulation and supplementary insulation
3.11
reinforced insulation
single insulation applied to live parts which provides electric shock protection level equivalent to double insulation under conditions specified hereof
3.12
functional insulation
insulation provided between live parts with different potentials only for the inherent function of motor
3.13
maximum loss point
operating point where the maximum loss occurs when the motor runs from no load to the rated load point
3.14
working voltage
maximum voltage withstood by the considered part when motor runs normally at the rated voltage
Note 1: The effects of different positions of controller and switchgear are considered.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Marking and instructions
5 Frame and enclosure
6 Mechanical assembly and parts
7 Corrosion resistance
8 Electrical connection
9 Connectors
10 Internal wiring
11 Electrical insulation support
12 Evaluation of insulation structure
13 Brush holder
14 Non-metal parts
15 Clearance and creepage distance
16 Grounding
17 Temperature rise test
18 Abnormal test
19 Durability test
20 Insulation resistance and electrical strength
21 Leakage current at working temperature
22 Damp heat test
23 Start
24 Components
25 Electromagnetic compatibility
26 Other requirements
27 Inspection rules
Annex A (Normative) Centrifugal switch
Annex B (Normative) Motor-run capacitor
Annex C (Normative) Motor-start capacitor
Annex D (Normative) Motor thermal protector
Annex E (Normative) Thermal link
Bibliography
Figure 1 Measuring circuit for leakage current of single-phase motor at working temperature
Figure 2 Measuring circuit for leakage current of three-phase motor at working temperature
Table 1 Tensile test of cord
Table 2 Cross-sectional area of wire to be connected by wiring terminal
Table 3 Torque test
Table 4 Minimum heat resistance temperature of lead wires for internal wiring
Table 5 Minimum clearance of motor
Table 6 Minimum creepage distance for basic insulation
Table 7 Temperature rise test limit
Table 8 Maximum allowable winding temperature in abnormal test
Table 9 Durability test time
Table 10 Voltage value on megohmmeter
Table 11 Overspeed test conditions
Table 12 Enclosure port
Table 13 DC power input/output ports
Table 14 AC power input/output ports
Table 15 AC power input port
Table 16 Inspection items