This presentation reviews procedures that explain how to identify unmarked leads of three-phase motors with one or two windings.

As with most tasks, there are many ways to terminate motor leads and each one has a following who believe it is the best method. Here we will discuss some of these procedures and outline a few of the advantages and disadvantages of each.

The markings on the external leads of a motor sometimes become defaced or are removed, which makes it necessary to identify and mark them before the motor can be properly connected to the line. This article will address lead identification of three-phase motors with 9 leads, based on the premise that none of the leads are marked. If some of the leads are marked, the process is the same, but may require fewer steps.

Si algunos están marcados, el procedimiento es el mismo, pero se requerirán  menos pasos Algunas veces, los cables de salida de los motores no se encuentran  iden-tificadoso sus marcas no  son legibles, por lo que se hace necesario  marcarlos para poder  conectar el motor adecua-damente  a la línea de alimentación. Este artículo se ocupará de cómo identificar los cables de los motores eléctricos con 9 cables de salida y se  basa en la premisa de que ninguno de los  cables se encuentra marcado. Si alguno de ellos estuviera identificado,el procedimiento es el mismo, pero se requerirán menos pasos.

When a customer calls and orders a motor, he usually specifies only the hp/kW rating, rpm, frame, enclosure and voltage rating. That leaves at least one critical area where the electrician can go wrong: The starting method and number of leads. As manufacturers produce more motors with 12 leads to increase versatility and reduce inventory requirements, there is an increased chance of error by the end user.

When repairing motors, we often take the lead wire ampacity charts for granted, without giving much thought to how they were developed. Who figured out how much current is acceptable for a specific lead wire, and why are there different ratings for different types of insulation? This article will cover some often-overlooked facts about ampacity.