American Petroleum Institute

Brushless Synchronous Machines - 500 kVA and Larger - Second Edition
 N STD 546

Annotation

1.1 Scope

1.1.1 This standard covers the minimum requirements for form-wound and bar-wound brushless synchronous machines in petroleum related industry service. This standard includes synchronous motors and generators with two different rotor designs:

a. The conventional salient-pole rotor with solid or laminated poles.

b. The cylindrical rotor with solid or laminated construction.

Note 1: A round bullet (•) at the beginning of a paragraph indicates that either a decision is required or further information is to be provided by the purchaser. This information should be indicated on the data sheets (see Appendix A); otherwise it should be stated in the quotation request or in the order.

Note 2: A square bullet ( ) at the beginning of the paragraph indicates additional requirements for special-purpose machines are: motors that drive high-inertia loads, vertical machines that support high-thrust loads, part of a complete train requiring vibration sensitivity criteria, operate in abnormally hostile environments, or are critical unspared equipment.

Note 3: This standard may be applied to adjustable speed motors with appropriate attention to the specific requirements of such applications. For adjustable speed applications, proper selection of the motor and drive is required to avoid the following conditions:

a. Motor rms current exceeding the continuous sinusoidal nameplate rating due to excessive voltage harmonics or improper volts/hertz levels.

b. Excessive winding temperature due to insufficient cooling, excessive torque levels, improper volts/hertz levels and increased losses due to harmonics.