When the time comes to replace an electric motor, or add another one, there are two main categories to choose from: General Purpose and Severe Duty Electric Motors. Choose correctly and you’ll have the most effective motor at the most cost-efficient price. Make the wrong call and someone up the chain will be very unhappy.
Here are some things to help you decide.
General Purpose Motors are generally less expensive. In fact, research has shown that they are usually in the neighborhood of 25% less. Sound good? It should. Especially if your motor is to be are used in fairly clean conditions and everyday applications such as pumps, fans, compressors, conveyors, etc.
General Purpose Motors can be either ODP or TEFC, and are regulated to ensure they meet NEMA’s premium efficiency regulations. They typically have ball bearings (or roller bearings for high radial load belted applications) and can range from having a frame that is made out of flat rolled steel, cast aluminum, or cast iron.
For most applications, a General Purpose Motor will fit the bill. You really don’t need a Severe Duty Electric Motor and getting one would be money down the drain.
But what if your application is far from ordinary, and very, very far from lab-like conditions? Then, what would happen to the initial cost savings of a General Purpose Motor?
If your application has even minor airborne contamination or undue mechanical stress, chances are a General Purpose Motor will fail, and its lifespan will be shortened considerably.
In tough, rugged applications and environments such as chemical processing, mining, foundry, pulp and paper, and waste management applications, a Severe Duty Motor is a must. And well worth every extra cent. They are built to protect against contamination, moisture, vibration and demanding duty cycles.
We have found that Siemens SD100 Severe Duty Motors (now called Simotics Electric Motors) are an industry workhorse and can handle extremely challenging environments without breaking a sweat. Baldor Electric Motors also has an extensive line of motors built to handle harsh industrial applications. We at HECO are a stocking distributor for both lines.
For the harshest industrial settings such as: paper & pulp, steel mills, cement & aggregate plants, power generation, you may need something even more robust. In those cases, an IEEE841 Motor can make sense. A good place to start is by looking at Siemens SD100 IEEE841 severe duty severe duty motors. Siemens Electric Motors have been designed to even exceed the IEEE 841-2001 standards for the petroleum and chemical industries.
If your motor operates in a clean environment with little undue mechanical stress, a Severe Duty Motor is probably overkill and a waste of money. If your motor is outside, subject to contamination, falling objects or nearby vibration, you’ll be dollars ahead by investing a little more now in a Severe Duty Motor.
Still not sure?
HECO can help you with any questions you may have about whether a General Purpose or Severe Duty Motor is best suited to your needs. We’ll begin by asking “Why?” Why do you need a motor? How will it be used? Where? Only after asking a lot of questions will we provide an answer. To learn more about what our “All Systems Go” approach can mean to you, please contact:
Justin Hatfield, VP of Operations
About the author:
Justin Hatfield is Vice President of Operations of HECO, Inc. He is responsible for Electric Motor & Drive Sales, Electric Motor & Generator Repairs, and Predictive Services. Justin was instrumental in developing HECO MAPPS (Motor And Powertrain Performance Systems) which focuses on “why” you have a motor problem instead of simply “What” product or service should be recommended.