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Vertical motors differ from horizontal motors in numerous ways, yet some view them as “just a horizontal motor turned on end.” The obvious differences are the (usually) thrust bearings, with arrangements varying from single- to three-thrust bearings with different orientations suited for specific load, rpm and applications. Less obvious differences are in the ventilation arrangements, shaft stiffness, degrees of protection and runout tolerances. This recording will cover those topics.

Regardless of the method used to detect winding temperature, the total, or hot spot, temperature is the real limit; and the lower it is, the better. Don’t let excessive heat kill your motors before their time.

This webinar recording discusses:

• Temperature rise (Method of detection, Insulation class, Enclosure, Service Factor)
• Increasing winding life (Insulation class, Cooling system, Winding redesign)

Although the earliest practical DC motor was built by Moritz Jacobi in 1834, it was over the next 40 years that men like Thomas Davenport, Emil Stohrer and George Westinghouse brought DC machines into industrial use.  It’s inspiring to realize that work-ing DC motors have been around for over 160 years. For the past century, DC machines over 30 or 40 kW have been cooled in the same manner – by mounting a squirrel cage blower directly over the commutator.

The evolution of electric motor design as it pertains to cooling methods provides insights about better ways to cool machines in service. The array of methods engineers have devised to solve the same problems are fascinating yet reassuring because many things remain unchanged even after a century of progress. This article discusses how motors are cooled and how heat dissipation can be improved for applications that fall outside the normal operating conditions defined by the National Electrical Manufacturers Association (NEMA) Standard MG 1.

We know that excessive temperature and moisture are the largest contributors to bearing and winding failures. Understanding the source of the increased temperature will help us to correct the problem and improve the machine’s life expectancy.

Whether an old or new design, lowering temperatures is based on the same principles. I've often commented on how fortunate we are to work on such a variety of electric motor designs. One day, you are working on a new design some designer has recently created, and the next day you are repairing a motor that could be in a museum. It's fascinating to see the different ways engineers have devised to do the same thing, and yet reassuring to see how many things remain unchanged even after a century of electric motors. One aspect of electric motors that could be placed in both categories is the way an electric motor is cooled. This article takes a look at how motors are cooled and how we can improve cooling for some of the special applications we encounter.

Frecuentemente escuchamos decir a nuestros miembros, que uno de sus clientes le ha informado que un motor que había sido reparado, ahora se calienta. Nosotros siempre les preguntamos ¿Qué tan caliente? y por lo general responden “Bueno, no puedo mantener mi mano sobre él”.

Vamos a pensar un minuto en esta respuesta. La mano del ser humano típico, puede soportar una temperatura entre 60-65°C (140-150°F), dependi-endo de las callosidades, el dolor que pueda tolerar, cuantas personas estén observando, etc. ... la temperatura es el enemigo número 1 de los motores eléctricos. Para optimizar la vida útil y el buen funcionamiento de los motores, se debe tener cuidado con el diseño, la aplicación y el mantenimiento de estas máquinas. Teniendo en cuenta todo lo anterior, no se considera seguro tocar con la mano la superfcie de un motor para saber si está muy caliente. En vez de esto, lo mejor es utilizar un termómetro.