Detail of GB 10068-2000

Introduction of GB 10068-2000

1 Scope This standard specifies the factory acceptance vibration test procedures and vibration limits for certain electrical machines under specified conditions, when uncoupled from any load or prime mover. It is applicable to d.c. and three-phase a.c. machines, with shaft heights 56 mm and higher and a rated output below 50 MW, at operational speeds from 600r/min up to and including 6000 r/min. For vertical and flange-mounted machines, this standard is only applicable to those capable of measuring in the free suspension state. This standard is not applicable to machines mounted in situ, three-phase commutator motors, single-phase machines, three-phase machines operated on single-phase systems, vertical waterpower generators, turbine generators or series-wound d.c. machines. Note: For machines measured in situ refer to applicable parts of ISO 10816-1 (foundation document). 2 Normative References The following normative documents contain provisions which, through reference in this standard, constitute provisions of this standard. At time of publication, the editions indicated were valid. All the standards will be revised, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of the following standards are applicable. GB 755-2000 Rotating Electrical Machines-Rating and Performance (idt IEC 60034-1:1996) GB/T 2298 1991 Mechanical Vibration and Shock—Terminology (neq ISO 2041:1990) GB 11348.1-1989 Mechanical Vibration of Non-Reciprocating Machines--Measurements on Rotating Shafts and Evaluation Criteria--Part 1: General Guidelines (ISO/DIS 7919-1) ISO 2954:1975 Mechanical Vibration of Rotating and Reciprocating Machinery-Requirements for Instruments for Measuring Vibration Severity ISO 8821:1989 Mechanical Vibration-Balancing-Shaft and Fitment Key Convention ISO 10816-1:1995 Mechanical Vibration-Evaluation of Machine Vibration by Measurements on Non-rotating parts-Part 1: General Guidelines ISO/DIS 10817-1 Rotating Shaft Vibration Measurement System Part 1 Transmission of Relative and Absolute Signals Vibrated by Rotating Shaft Radiation 3 Terms and Definitions For the purposes of this document, the terms and definitions given in the normative references listed in GB/T 2298 and Chapter 2 apply. 4 Measurement Quantities 4.1 General Measurement quantities are the vibration velocity at the machine bearings and the relative shaft vibration displacement within or near to the machine bearings. 4.2 Vibration magnitude The criterion for the vibration magnitude at the machine bearings shall be the vibration velocity in millimetres per second in the frequency range. The greatest value, determined at the prescribed measurement positions, according to this standard, characterizes the vibration magnitude of the machine (see ISO 10816-1). Induction motors (especially of two pole type) frequently show vibration beating at twice slip frequency. In these cases, the decisive vibration magnitude shall be determined from the relationship:

Contents of GB 10068-2000

Foreword I 1 Scope 2 Normative References 3 Terms and Definitions 4 Measurement Quantities 5 Measurement Equipment 6 Machine Mounting 7 Conditions of Measurement 8 Limits of Bearing Housing Vibration 9 Limits of Relative Shaft Vibration Bibliography