Design Alone Is Insufficient to Meet API 541 Fifth Edition Requirements for Reliability: Key Components for Achieving Service Life Conditions

The fifth edition of American Petroleum Institute (API) 541 [2] extended the uninterrupted continuous operation of motors covered by the standard from three to five years and the service life of machines from 20 to 25 years. The standard recognizes that uninterrupted operation for this time period involves factors beyond the vendor’s control. This article provides design, manufacturing, application, and monitoring aspects that will assist the end user in achieving these new service condition requirements. This article discusses the importance of lubrication, ways to maintain low vibration levels from start-up and during operation, accessories to protect vital machine components, the selection of the proper enclosure for an application, stator winding connections, and the proper use of space heaters in the field.