Facebook Twitter LinkedIn YouTube Menu Search Arrow Right Arrow Left Arrow Down Arrow Up Home Arrow Next Arrow Previous RSS Icon Calendar Icon Warning Icon

Filter the results

  • Enter one or more words to find resources containing any of the words entered
  • Enter words or phrases between " " to find exact match

Resource categories

Resource Library

Stator Rewinds: When Things Get Tight

  • March 2024
  • Number of views: 1134
  • Article rating: 3.0
Webinar recording

When preparing to rewind random or form-wound status, sometimes there just doesn’t seem to be enough room in the stator slot for the desired conductor area and insulation quantities. This presentation looks at balancing stator copper losses against insulation reliability.

Why “White Coils” are a “Red Flag”

The importance of preventing the ingress of air during global vacuum pressure impregnation of form-coil windings

  • September 2022
  • Number of views: 2550
  • Article rating: 3.3
Article

The goal of vacuum pressure impregnation is complete saturation of a winding with insulating resin. As resin penetrates the insulating materials, it causes them to darken. If some insulation is a lighter shade, the coil or jumper is not fully saturated. The winding is not properly protected, and if the problem is not addressed, it is likely to cause premature failure of the unit. This could result in costly warranty work, or at a minimum, will be a failure to provide your customers with the quality they expect and deserve.

Porqué las "Bobinas Bancas" son una "Señal de Alarma"

La importancia de prevenir el ingreso de aire durante la impregnación global por vacío y presión de los bobinados preformados

  • September 2022
  • Number of views: 1844
  • Article rating: No rating
Article

El objetivo de la impregnación por vacío y presión (VPI) es saturar completamente un devanado con resina aislante. A medida que la resina penetra en los materiales aislantes, los oscurece y al drenar la resina VPI del devanado, todo el aislamiento de las cabezas queda oscuro en un tono uniforme. El aislamiento de la conexión también debe quedar oscuro de forma pareja. Si algún aislamiento muestra un tono más claro, la bobina o el puente no han quedado completamente saturados y el devanado no está debidamente protegido. Si no se soluciona el problema, es probable que esto provoque un fallo prematuro en el equipo. Esto podría generar una garantía costosa o, como mínimo, la reparación no brindará a sus clientes la calidad que esperan y merecen.

AC Stator Form Coil Data Sheet

  • February 2021
  • Number of views: 7502
  • Article rating: 3.5
Form/Worksheet

This handy form provides fields to record all of the details needed to document and/or order replacement coils for an AC form-wound machine. The form also includes detailed descriptions/definitions of the data to be recorded in each field. 

Controlling Stator Copper Losses in Formed Coil Rewinds

  • May 2020
  • Number of views: 10588
  • Article rating: No rating
FREE for Members of EASA
Webinar recording

This webinar recording looks at several aspects of winding design to prevent increased temperature rise and decreased efficiency.

Consideraciones para convertir bobinados de alambre redondo a pletina (solera)

  • December 2019
  • Number of views: 8971
  • Article rating: No rating
Article

Con el aumento continuo de los tamaños de los motores CA y la obvia superioridad de los devanados con bobinas preformadas (pletina o solera), un área en la que podemos ayudar a mejorar la confiabilidad de los motores de nuestros clientes es rediseñando estos motores grandes de alambre redondo para que acepten bobinas preformadas. La mayoría de los reparadores estarían de acuerdo en que las máquinas de alambre redondo por arriba de 600 hp (450 kW) deberían rediseñarse con bobinas preformadas. Así mismo, aquellas con tensiones nominales superiores a 2 kV serían más confiables con bobinas de pletina.

Nadie quiere rebobinar un motor con 60 #14 AWG (62- 1.6 mm). Con la abundancia de proveedores especializados en laminaciones de estatores, el costo y la practicidad para convertir motores de alambre redondo a pletina está al alcance de casi todos los centros de servicio. Las laminaciones para reemplazar el núcleo pueden ser troqueladas o cortadas con láser o agua y entregadas en tiempos muy razonables.

Magnetic Wedges

  • February 2019
  • Number of views: 13769
  • Article rating: 5.0
Webinar recording

An increasing number of manufacturers are using magnetic wedges in their form-wound machines. When a winder fails to replace magnetic wedges in kind, the winding temperature rise can increase by 20°C, and the magnetizing current can increase by 20% or more.

Surge test levels for form wound stators

  • December 2016
  • Number of views: 5975
  • Article rating: 3.0
Article

The question of surge test voltage levels used for testing the turns insulation of form wound stators comes up often. And, why wouldn’t it? Many service centers have several good coil suppliers in their qualified supplier lists and quite a few customers who own form wound motors. It’s not unlikely that each of the coil suppliers and each of the customers could be specifying different test levels. What’s more, most authoritative standards or guides available provide a range of test levels. This is because not all insulation systems are designed to have the same surge withstand capability. Also, the turn insulation properties of one particular system can vary widely depending on the extent of processing complete at the time of test.

Niveles para la prueba de impulso en estatores de pletina

  • December 2016
  • Number of views: 5835
  • Article rating: No rating
Article

La pregunta sobre los niveles de tensión utilizados en la prueba de impulso para comprobar el aislamiento entre espiras de los estatores de pletina surge muy a menudo. ¿Y por qué nos la hacemos? Muchos centros de servicio tienen buenos fabricantes de bobinas en sus listados de proveedores calificados y varios clientes que poseen motores de pletina. No es improbable que cada fabricante de bobinas y cada cliente puedan especificar niveles de prueba diferentes. Aún más, la mayoría de las normas o guías disponibles proporcionan un rango de niveles de prueba. Esto es debido a que no todos los sistemas de aislamiento están diseñados con la misma capacidad para soportar impulsos. Además, las propiedades del aislamiento entre espiras de un sistema en particular pueden variar ampliamente, dependiendo del grado de procesamiento alcanzado al momento de la prueba.

Benefits of the AC hi-pot for new form coil stator windings

  • August 2013
  • Number of views: 7034
  • Article rating: No rating
Article

The October 2012 Currents article titled "How to properly test AC stator and wound rotor windings" provides a thorough explanation on the proper application of insulation resistance, winding resistance, surge testing and high potential testing for stators and wound rotors. The article emphasizes that NEMA MG 1-2011 specifies AC and DC high potential (hi-pot) test levels for new windings and does not recommend repeated application of the high potential test. This is reinforced in EASA's Recommended Practice for the Repair of Rotating Electrical Apparatus (ANSI/EASA AR100-2010) which calls for reduced voltage levels for repeated tests should they be required. This article is intended to provide additional information on the high potential test performed on new windings. Specifically, it addresses the advantages of AC high potential testing for new, form coil stator windings. Topics discussed include: A real-world example Destructive test? Sizing the AC test set Example calculation Bibliographic references to additional reference materials

Getting The Most From Your Electric Motors

Getting The Most From Your Electric Motors - coverThis 40-page booklet provides great advice for obtaining the longest, most efficient and cost-effective operation from general and definite purpose electric motors.

This booklet covers topics such as:

  • Installation, startup and baseline information
  • Operational monitoring and maintenance
  • Motor and baseline installation data
  • How to read a motor nameplate
  • Motor storage recommendations

LEARN MORE AND DOWNLOAD MÁS INFORMACIÓN Y DESCARGAR BUY PRINTED COPIES

READ MORE ABOUT THE FEATURES AND BENEFITS

EASA/AEMT Rewind Study

EASA Rewind Study cover

The Effect of Repair/Rewinding on Premium Efficiency/IE3 Motors
Tests prove Premium Efficiency/IE3 Motors can be rewound without degrading efficiency.

DOWNLOAD THE FULL RESULTS

ANSI/EASA AR100-2020

ANSI/EASA AR100-2015 cover

Recommended Practice for the Repair of Rotating Electrical Apparatus
This is a must-have guide to the repair of rotating electrical machines. Its purpose is to establish recommended practices in each step of the rotating electrical apparatus rewinding and rebuilding processes.

DOWNLOAD - ENGLISH

DESCARGAR - ESPAÑOL

EASA Technical Manual

EASA Technical Manual cover

Revised September 2022
The EASA Technical Manual is the association's definitive and most complete publication. It's available FREE to members in an online format. Members can also download PDFs of the entire manual or individual sections.

VIEW & DOWNLOAD