Detail of GB 10068-2008

Introduction of GB 10068-2008

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 120r/min up to and including 15000 r/min. 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, turbonator with capacity larger than 20MW and magnetic bearing machine or series-wound machines. Note: For machines measured in situ refer to applicable parts of ISO 10816-1 and ISO 7919. 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 755-2008 Rotating Electrical Machines-Rating and Performance (IEC 60034-1: 2004, IDT) GB/T 997 Rotating Electrical Machines-Classification of Types of Construction Mounting Arrangements and Terminal Box Position of (IM Code) (GB/T 997-2008, IEC60034-7: 2001, IDT) ISO 2954 Mechanical Vibration of Rotating and Reciprocating Machinery-Requirements for Instruments for Measuring Vibration Severity ISO 7919-1 Mechanical vibration of non-reciprocating machines-Measurements on rotating shafts and evaluation criteria-Part 1: General guidelines ISO 8821 Mechanical Vibration-Balancing-Shaft and Fitment Key Convention ISO 10816-1 Mechanical Vibration-Evaluation of Machine Vibration by Measurements on Non-rotating parts-Part 1: General Guidelines ISO 10816-3 Mechanical vibration - Evaluation of machine vibration by measurements on non-rotating parts-Part 3: Industrial machines with nominal power above 15 kW and nominal speeds between 120 r/min and 15000 r/min when measured in situ ISO 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 Clause 2 apply. 4 Measurement Quantities 4.1 General Measurement quantities are the vibration displacement, speed and acceleration at the machine bearings and the relative shaft vibration displacement within or near to the machine bearings. 4.2 Vibration strength The criteria for the vibration strength at the machine bearings are root mean square value of vibration displacement (μm), vibration speed and vibration acceleration. The greatest value, determined at the prescribed measurement positions, according to this standard, characterizes the vibration strength of the machine. Induction motors (especially of two pole type) frequently show vibration beating at twice slip frequency. In these cases, the decisive vibration strength shall be determined from the relationship:

Contents of GB 10068-2008

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