IEEE Std 841:2021 pdf free download – IEEE Standard for Petroleum andChemical lndustry – Premium-Efficiency, Severe-Duty,Totally Enclosed Squirrel Cagelnduction Motors from 0.75 kW to 370 kW(1 hp to 500 hp)
1.1 Scope
This standard applies to premium-efficiency totally enclosed fan-cooled (TEFC) and totally enclosed non-ventilated (TENV), horizontal and vertical, single-speed, squirrel cage polyphase induction motors,0.75 kWto 370 kW (1 hp to 500 hp), and up to 4000 V nominal, in National Electrical Manufacturers Association(NEMA)frame sizes 143Tand larger, for petroleum, chemical, and other severe-duty applications(commonlyreferred to as premium-efficiency severe-duty motors).Excluded from the scope of this standard are motorswith sleeve bearings and additional specific features required for explosion-proof motors.
1.2 Purpose
The purpose of this standard is to define a specification that deals with mechanical and electrical performance,electrical insulation systems,corrosion protection， and electrical and mechanical testing for severe-dutytotally enclosed squirrel cage polyphase induction motors,0.75 kW to 370kW (1 hp to 500 hp), for petroleum,chemical, and other severe-duty applications (commonly referred to as premium-efficiency severe-dutymotors). Many of the specified materials and components in this standard stem from experience with severelycorrosive atmospheres and the necessity for safe, quiet, reliable, premium-efficiency motors.
14.1 Introduction
This clause is included to assist purchasers, end users, specifiers, and manufacturers of IEEE 841 motorscovered by this standard to provide guidance in what is considered the core technical features of an “IEEEStd841-2021″motor, and allowable options.”IEEE Std 841-2021″motors are what is intended to be standardizedor stocking inventory. This clause is also intended to provide guidance as to options that when applied tomotors otherwise built to this standard would result in a motor that would be marked with the phrase “IEEEStd 841-2021 Features”(i.e., custom motors manufactured for a specific application).These are not intendedto provide the means of standardizing or stocking inventory of custom manufactured “IEEE Std 841-2021Features”motors, but to provide guidance on options that preclude a motor from having an“IEEE Std 841-2021″ compliant label. Lastly, the motor needs to be marked or labeled in such a manner that reflects “IEEEStd 841-202l Features” to minimize the potential confusion with a fully compliant “IEEE Std 841-2021″motor.
A motor labeled “IEEE Std 841-2021” will meet the standard without exception and all of the core technicalfeatures in 14.2.Most manufacturers make these motors up to 500 hp which makes them in many cases off theshelf and interchangeable. In addition, motors that are manufactured to order meeting this standard withoutexception and with any of the allowable options in 14.3 can be labeled a “IEEE Std 841-2021″motor.
A motor labeled “IEEE Std 841-2021 Features” is built to this standard, but has any of the characteristics)features in 14.4.
NOTE—Vertical motors purchased in combination with pumps (vertical overhung and vertically suspendedtypcs) specified in accordance with API Std 610[B3] may have more stringent thrust-bearing loading definitionand life requirements than specified in item c) and item d) of 7.1.For vertical overhung and vertically suspendedapplications, both the motor and the pump impose radial and thrust loading on the motor bearings.The maximumradial and thrust loading that occurs during start-up and end-of-pump-curve operation can be severe and difficultto predict, and conservatism in bearing specification is recommended.