Do you know what motor you should use when operating in a harsh, heavy or severe duty environment? At minimum, you should be using a Total Enclosed Fan Cooled (TEFC) Severe Duty (SD) motor. But, where do you turn when a standard severe duty motor just isn’t enough? One option worth exploring is an IEEE-841 motor.
Who created the standard?
The acronym IEEE stands for the Institute of Electrical and Electronics Engineers. The IEEE serves as a leading authority and developer of industrial standards in areas such as telecommunication, electric power and consumer electronics.
Why was the standard created?
The IEEE-841 standard was created to address the special requirements of the continuous process of the Petroleum & Chemical Industry and to improve the reliability, efficiency and performance of severe duty motors in their applications. It’s worth noting that other manufacturing sectors, such as the Pulp & Paper Industry, have widely adopted the standard as well.
What does the standard specify?
The IEEE Standards Association states that the "standard applies to premium efficiency, totally enclosed fan-cooled (TEFC), horizontal and vertical, single-speed, squirrel cage polyphase induction motors, up to and including 370kW (500 hp), and 4000 V in National Electrical Manufactures Association (NEMA) frame sizes 143T and larger, for petroleum, chemical, and other severe-duty applications (commonly referred to as premium-efficiency severe-duty motors). Excluded from the scope of this standard are motors with sleeve bearings and additional specific features required for explosion-proof motors.”
Notable IEEE-841 Specifications
- 5 Year warranty
- Usual Service Conditions: i.e. ambient temperature (-25°C to + 40°C), full voltage starting, severe duty, application in Class I Division 2 areas & max altitude level
- NEMA frame assignments (143T and larger)
- Includes T & TS shaft extensions
- Cast Iron construction
- Single voltage (200V, 230V, 460V, 575V); Dual voltage is only acceptable for 2300V & 4000V ratings.
- Synchronous speed ratings (60Hz = 900, 1200, 1800 & 3600 RPM).
- TEFC (TENV) enclosure & IP55
- NEMA Design B torque/current characteristics and starting capabilities
- Minimum Class F insulation system
- Form wound, sealed insulation for 2300V and above
- Max 200°C surface temperature & non-sparking fan
- Unfiltered vibration not to exceed 0.08 in/s (3600, 1800 & 1200 RPM)
- Unfiltered vibration not to exceed 0.06 in/s (900 RPM)
- Unfiltered axial vibration not to exceed 0.06 in/s
- Corrosion Resistance to frame, endshields, fan covers & terminal housings
- Internal Corrosion Resistance to stator, rotor and shaft surfaces
- Testing Information: Winding resistance, no load current, voltage, speed and 5 unfiltered vibration readings are supplied with each individual motor.
Many manufacturers make IEEE-841 motors such as Siemens, GE, ABB, Marathon, Etc. All must meet the requirements of the specification for any motor they sell as an IEEE-841 motor. However, beyond the specific required items in the specification, manufacturers will have different features and testing that they do above and beyond the specification. These will vary from manufacturer to manufacturer.
If you’re looking for a reliable motor that helps reduce downtime, has low noise levels, includes a corrosion resistant enclosure and is extremely interchangeable – an IEEE-841 motor might just be the solution you’ve been searching for.
HECO - All Systems Go
About the author:
Nolan Crowley is a Territory Development Manager for HECO - All Systems Go in the Greater Cincinnati & Ohio River Valley area. Nolan is focused on helping customers solve problems and increase reliability. He has over 10 years of experience in the electric motor and rotating equipment industry.