IEEE Std 334:2006 pdf free download

IEEE Std 334:2006 pdf free download.IEEE Standard for Qualifying Continuous Duty Class 1E Motors for Nuclear Power Generating Stations.
4.1 General
The primary role of qualification is to provide reasonable assurance that Class I E motors can perform their specified safety functions and that no failure mechanisms exist that can lead to a common-cause failure under the postulated service conditions.
Motors exhibit aging mechanisms in their insulation systems. For this reason, the following shall apply:
a) For motors located in a mild environment and having no significant aging mechanism, a qualified life is not required. Where seismic qualification is required for motors located in a mild Plant environment, age conditioning is required only when significant aging mechanisms exist. A maintenancedsurveillance program based on the vendor’s recommendations, supplemented with operating experience, should provide adequate assurance that the motor will perform its intended safety function.
b) Degradation over time, followed by exposure to environmental extremes of temperature. vibration, and, if applicable, chemical spray and submergence resulting from a design.hasis. event condition, can precipitate common-cause failures of Class ll motors. For this reason, for motors subject to harsh environment with significant aging mechanisms, an insulation system qualified life shall be established in accordance with this standard. The qualified life determination must consider degradation of the insulation system’s capability prior to and during service. In establishing a qualified life, a qualified condition must also be established. This qualified condition is the state of degradation for which successful performance during a subsequent design basis event was demonstrated.
Seals, gaskets, and other nonmetallic components used in the manufacture of motors may have significant aging mechanisms and shall be evaluated.
Wear and aging mechanisms also exist for bearings and lubrication. This standard sets forth requirements to define replacement and maintenance intervals that consider the manufacturer’s recommendations and are based on actual service and operating conditions.
For all qualification programs, the result shall provide documentation demonstrating the motor’s adequacy to perform its safety function(s). The documentation shall be in a form that allows verification by competent personnel.
The principles of this standard also should be applied to modified or refurbished motors.
The methods for qualifying motors are described in 4.2.1 through 4.2.4.