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Articles in Industry Publications

Conversión de Aluminio a Cobre: Lo que Necesita Saber

  • December 2023
  • Number of views: 2530
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Webinar recording

¿Recibió un motor antiguo bobinado con alambre de aluminio? Este webinario explicará como realizar la conversión adecuada de alambre de aluminio a alambre de cobre en máquinas de CA y CC, incluyendo ejemplos para el rebobinado de estatores y campos shunt.

Interpoles and Compensating Windings in DC Machines – What Do They Do?

  • December 2023
  • Number of views: 3486
Article

Unlike their AC counterparts, DC machines do not have rotating magnetic fields. Rather, there are fixed magnetic field axes for the field (direct axis) and armature (quadrature axis). Even though the armature is rotating, the magnetic field axis in the armature is fixed thanks to commutation, which allows the direction of current in an armature conductor to change as it passes from the region under one main field pole to the next.

Interpolos y Devanados de Compensación - ¿Qué es lo que hacen?

  • December 2023
  • Number of views: 2116
Article

A diferencia de sus homólogos de CA, las máquinas de CC no tienen campos magnéticos rotativos. Más bien, existen ejes de campo magnético fijos para el campo (eje directo) y la armadura (eje en cuadratura). Aunque la armadura esté girando, el eje del campo magnético de la armadura está fijo gracias a la conmutación, lo que permite que la dirección de la corriente en un conductor de la armadura cambie a medida que pasa debajo de un polo de campo principal al siguiente.

How to Measure Magnet Wire

  • March 2023
  • Number of views: 3341
Video

This video shows one step in collecting motor winding data: how to measure magnet wire.

Mitigating Risk with Insulation Systems

  • September 2021
  • Number of views: 12651
Article

Relevant standards including IEC 60085 and IEEE 1 have similar definitions for electrical insulating materials (EIM) and electrical insulation systems (EIS). As with any system, there is an interaction between the materials used, and the insulation system developers take great care to ensure that this interaction does not lead to undesirable outcomes.

Mitigando El Riesgo En Los Sistemas De Aislamiento

  • September 2021
  • Number of views: 11674
Article

Diferentes normas relevantes incluyendo la IEC 60085 y la IEEE 1 definen de forma similar los materiales electro aislantes (EIM) y los sistemas de aislamiento eléctrico (EIS). Como en cualquier sistema, existe una interacción entre los materiales usados y los diseñadores de los sistemas de aislamiento cuidan todos los detalles para evitar que esta interacción produzca resultados indeseados.

DC Machine Data Sheet

  • December 2020
  • Number of views: 14239
Form/Worksheet

EASA's DC Machine Data Sheet provides all the fields necessary on a simple one-page form to accurately record all the details about the machine being repaired.

DC Motor Electrical Procedures

  • April 2020
  • Number of views: 11563
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DC Machine Inspection Report

  • August 2016
  • Number of views: 17470
Form/Worksheet

A convenient incoming inspection report for basic DC motor conditions and test values.

DC Machine As-Received Connection Form (2-, 4- and 6-Pole DC Machines)

  • August 2016
  • Number of views: 12437
Form/Worksheet

This inspection report helps record a DC motor's connection as it enters the service center. It is intended for use with 2-, 4- and 6-pole DC machines.

What’s new in the IEEE 43 insulation resistance testing standard?

  • April 2016
  • Number of views: 23766
Article

The Institute of Electrical and Electronics Engineers (IEEE) standard for insulation resistance testing of motor and generator windings that was published in 2002 has been revised. The 2013 edition was published in March 2014. This article examines the changes to the standard.

¿Qué hay de nuevo en la norma para pruebas de resistencia de aislamiento IEEE 43?

  • April 2016
  • Number of views: 37361
Article

La norma para realizar las pruebas de resistencia de aislamiento en los devanados de motores y generadores del Instituto de Ingenieros Eléctricos y Electrónicos (IEEE), publicada en el 2002 ha sido revisada. La edición del 2013 fue publicada en Marzo del 2014. Este artículo examina los cambios al estándar.

Keeping it cool: A look at causes of motor overheating

  • March 2015
  • Number of views: 15550
Article

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.

Considerations when working with compound wound DC fields

  • December 2014
  • Number of views: 7402
Article

Occasionally a customer wants a spare DC machine, and you find a replacement that is almost – but not quite – identical. Often, either the original or the spare is compound wound. The customer then asks: “What do the series fields do?” and “Can we just isolate the series leads?”  There are a couple of considerations, but the answer is that “it depends.”

DC shunt field rewinding wire size considerations

  • January 2014
  • Number of views: 6803
Article

When rewinding the shunt fields of a DC machine, it is important to avoid making changes that could negatively impact performance. The recommended practice is to maintain the manufacturer’s winding configuration during the repair. That is, the field circuit connection, turns per coil, mean or average length of turn (MLT) and wire size should not be changed. However, service centers do sometimes encounter issues around wire size availability. The purpose of this article is to provide some guidance for making wire size substitutions when the original size is unavailable.

Aluminum-to-copper magnet wire winding conversions: Considerations for deciding whether wire area should be reduced

  • December 2011
  • Number of views: 15314
Article

Although aluminum magnet wire theoretically can be converted to copper magnet wire of about 5/8 of the original wire area, in some cases this is not advisable. In others, it may result in a change in the magnetic strength of a coil or winding. In this article we will address the most common aluminum-to-copper magnet wire conversions as well as how to deal with whether the wire area should be reduced. Topics discussed include:

  • AC motor windings
  • Shunt fields
  • Series fields and interpoles
  • Transformer windings

Follow these procedures to reduce problems when rewinding field coils

  • April 2008
  • Number of views: 7017
Article

When rewinding field coils, there are a couple of common problems that make life difficult for the service center. One problem occurs when the newly rewound set of shunt fields is returned to the service center, roasted again. What causes this, and whether we can improve our winding procedure, has been the subject of much discussion. We all realize that something caused that first failure. If the subsequent failure looks a lot like it - the shunt fields were charred in both cases then it seems logical that the underlying cause could be the same. Sometimes it is. Let's look at why the coil is burnt. Well sure, it got too hot. But why? Is it because the shunts are energized when the machine is otherwise shut down? If so, the fields can be automatically de-energized after "x" minutes of machine inactivity. Installing a timed relay in the controls will avoid future problems. It may be that the customer is able to trace the problem to a new operator, who needs more training.

Trickle heating is a practical option to prevent condensation

  • April 2006
  • Number of views: 11038
Article

Trickle heating is another very practical option to heat AC stator windings or DC field windings while they are not energized.

Training Film 21: Testing DC Machines

  • June 1987
  • Number of views: 14659
Video

Training Film 19: Layer-Winding DC Field Coils

  • June 1985
  • Number of views: 8988
Video

Covers all necessary steps for layer-winding DC field coils, how to layer-wind a shunt field coil, how to reinsulate an interpole field coil, and how to install large field coils in the frame.

Training Film 18: Random-Winding DC Field Coils

  • June 1984
  • Number of views: 8709
Video

Illustrates procedures for manufacturing random-wound interpole and main field coils for DC machines. Covers everything from removing old coils and taking data to installing and connecting new coils, including how to construct winding forms and jigs, how to shape coils to conform with the curvature of the field frame and how to insulate field coils. Both “wet” and “dry” winding techniques are illustrated.