Standarder 803970

Solo disponible en BuenasTareas
  • Páginas : 10 (2270 palabras )
  • Descarga(s) : 0
  • Publicado : 17 de agosto de 2012
Leer documento completo
Vista previa del texto
Standards
International standardisation work in the field of electrical engineering is well developed. There are two organisations: IEC (International Electrotecnical Commission) and CENELEC (Comité Européen de Normalisation Electrotechnique). IEC works on global scale while CENELEC concentrates on regional work in Western Europe. The International Standardisation Organisation ISO also hasparticular interest in electric motors. The IEC has some 45 member countries; CENELEC has 17. The aim of CENELEC is to remove obstacles to technical trade in Western Europe due to differences in regulations and standards. Existing IEC publications are generally used as a basis, but additions can be made. New national standards are increasingly identical to or largely based on Europeans standards issuedby CENELEC. The offered motor shall at the time of delivery comply with all the relevant standards and specifications, in particular the following:
Title General requirements for rotating electrical machines Fixing dimensions and assignment of rated output with IM B 3 Standard IEC 34-1 IEC 85 IEC 72

Terminal markings and direction of rotation of IEC 34-8 rotating electrical machines Types ofconstruction of rotating electrical machines Method of cooling rotating electrical machinery Degrees of protection by enclosures for rotating electrical machinery Vibration severity of electrical machines Parallel shaft extensions for electrical machines Noise emission limits Starting performance IEC standard voltages IEC 34-7 IEC 34-6 IEC 34-5 IEC 34-14, ISO 2373 IEC 72 IEC 34-9 IEC 34-12 IEC 38Methods for determining losses and efficiency IEC 34-2 of rotating electrical machinery from test

1 Tolerances 1.1 Electrical data The following tolerances according to IEC 34-1 are permitted:
Table I. Electrical tolerances
Performance characteristic indirect calculation Efficiency direct method Power factor Permissible tolerance - 15% of (1-η) PN ≤ 50 kW - 10% of (1-η) PN > 50 kW - 15% of(1-η) Notes

.

min 0.02 max 0.07

Slip Starting current Starting torque Pull-up torque Pull-out torque Moment of inertia Noise level

at rated load operating temperature in the planned starting circuit

±

20% ατ ΠN ≥ 1 kW
without restriction downwards

+ 20% + 10% for frame size 56 - 160 - 15% and + 25% - 15 % - 10% ±

with the applications of the tolerance TK/TN at least 1.610%
sound pressure level

+ 3 dB(A)

These tolerances are permissible for the values assured for three-phase asynchronous motors, taking the necessary manufacturing tolerances and material variations of the raw materials used, into account. 1.2 Mechanical parameters
Table II. Mechanical fit or tolerances
Mechanical dimension Largest width of motor (without terminal box) Overall length ofmotor Overall height (lower edge foot, housing or flange to highest point of motor) Fit or tolerance + 2% + 1% + 2%

2 Frame sizes In the IEC-publication 72-1 (1991) frame sizes and the most essential fixing dimensions are fixed and co-ordinated to the individual frame size.

Table III. Frame size

Thread A/mm 71-14 80-19 90S24 90L24 100L28 112M28 132S38 112 125 140 140 160 190 216 B/mm 90100 100 125 140 140 140 C/mm 45 50 56 56 63 70 89 D/mm 14 19 24 24 28 28 38 E/mm 30 40 50 50 60 60 80 F/mm 5 6 8 8 8 8 10 G/mm 11 15.5 20 20 24 24 33 H/mm 71 80 90 90 100 112 132 M6 M8 M8 M8 M10 M10 M10

132M38 160M42 160L42 180M48 180L48 200M55 200L55

216 254 254 279 279 318 318

178 210 254 241 279 267 305

89 108 108 121 121 133 133

38 42 42 48 48 55 55

80 110 110 110 110 110110

10 12 12 14 14 16 16

33 37 37 42.5 42.5 49 49

132 160 160 180 180 200 200

M10 M12 M12 M12 M12 M16 M16

3 Types of duty Various types of duty have been defined in terms of how the load, and thus the output of the motor, varies with time. The rated output for each type of duty is determined in a load test which the motor must undergo without the temperature limits laid down in IEC...
tracking img