Tough Conditions Require Tough Equipment

Tough Conditions Require Tough Equipment


When the application offers the type of conditions you wouldn’t go out in voluntarily on a bet, you need to think about using some severe service equipment. When the job in question is a natural for an electric motor, you have an easy and best answer. It’s spelled IEEE 841.

Siemens designates their motors for these jobs as RGZEESDX and rates them NEMA Premium. They exceed IEEE 841-2001 standards for energy efficiency, high performance, variable speed operation, rugged construction and long service life for the most demanding applications. They are the real deal.

They are ideal for use in chemical processing, mining, foundry, pulp and paper, waste management and petro-chemical applications.

Locations that are wet or contain corrosive atmospheres are tough on “normal” motors, so IEEE 841 is a natural answer.

Corrosives can be liquids, gases, or solids. They can affect not only the electrical insulation but the mechanical parts of the motor as well. Frequently called “mill and chemical duty,” the equipment may be fitted with corrosion-resistant epoxy enamel paint system; coating of the rotor and and stator surfaces; stainless steel hardware; bearing seals; and Class F/Class H insulation systems.

Other challenges to motor life expectancy include dust and dirt, fungi and other microorganisms and internal condensation. Devices such as bearing seals prevent contaminants from entering the motor and careful attention to insulation systems protect the motor when contaminants cannot be excluded.

Specific features of Siemens RGZEESDX include:

Frame and End Shields
Cast iron construction for exceptional structural integrity with condensation T-drains. Lifting eyebolts are included for all frames.

A unique offset rotor bar design provides improved efficiency while larger bars and end rings reduce resistance for lower rotor losses. Each die cast aluminum rotor assembly is precision balanced to ISO G1.0 for extended bearing life, and includes a high-strength carbon steel (C1045) shaft for maximum rotor performance.

Manufactured with premium C-5 electrical grade steel laminations and copper electrical magnet wire to lower losses for improved efficiencies. A unique stator core design lowers flux density while increasing cooling capacity. Large conductor cross section reduces resistance, also lowering stator losses.

Proprietary inverter-rated Class F non-hygroscopic insulation system with NEMA Class B temperature rise, provides an extra margin of thermal life. Varnish system application ensures maximum wire penetration to provide protection from moisture, corrosion and electrical shock. This insulation system meets or exceeds NEMA MG1-2003, Part 31 making all motors suitable for operation with variable frequency drives.

A bi-directional, non-sparking fan is locked and keyed to the shaft. Its low-inertia design reduces windage losses, improves airflow, reduces noise and provides dependable cooling. Cast iron fan covers are provided on all frame sizes.

Regreasable, oversized single shielded with cast iron inner caps. Alemite grease inlet fittings and automatic grease relief fittings for ease of routine maintenance. Inpro/Seal

A specially formulated, high temperature tested, polyurea based grease is used to provide more than four times the lubrication life of other polyurea greases. Seamless, grease filled lubrication pipes are included.
Oversized Conduit Box
Cast iron construction that is larger than industry standards, diagonally-split, neoprene gasketed and rotatable in 90° increments for quick and easy connections. Includes a ground lug and non-wicking, clearly and permanently marked leads.
Corrosion Resistance
Cast iron construction, zinc-plated hardware, epoxy enamel paint and embossed stainless steel nameplate resist rust and corrosion.
Performance Specifications of Siemens RGZEESDX IEEE 841 Electric Motors include:
  • 1 to 400 HP
  • 1.15 service factor, 40°C ambient
  • 3600, 1800, 1200 or 900 RPM
  • 3 phase, 60 Hz; 460 volt; 575 volt available
  • 143T through S449 frame
All Siemens motors are available with a wide variety of modifications to meet specific motor needs.
To learn more about IEEE 841 motors, other Siemens components, or about any other aspect of IBT’s broad range of electric motors and drives, please contact us



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