Identifying unmarked leads in three-phase motors is a common task for service center technicians. This article provides one way to assign lead numbers for a 12-lead machine with unmarked leads.

Have you ever been out at a restaurant or sports bar to meet up with some friends and colleagues to have an adult beverage or two when suddenly someone leans on the table ever so slightly and liquid spills everywhere? What just happened? The small space between the table leg and the floor has just created a big consequence. While it’s not too difficult to solve if you have some napkins and a few coasters, it does, however, illustrate the results of a soft foot and how a very small space can lead to a much larger consequence.

A tilted or improperly sized oil standpipe can allow oil to migrate upward along the pipe’s wall when the motor is in operation, leading to leakage, loss of lubrication and potential bearing damage. This issue can be overlooked during assembly or inspection, but a few simple checks can prevent costly problems. 

Often when we are dealing with three-phase squirrel cage motors we ask ourselves “Is there a standard or a rule of thumb for this motor characteristic?” The 10 characteristics that follow apply to conditions associated with motor starting as well as steady state operation. Examples are provided for each of the characteristics.

A menudo, cuando trabajamos con motores trifásicos jaula de ardilla, nos preguntamos: "¿Existe una norma o regla general para esta característica del motor?". Las siguientes 10 características aplican tanto al arranque del motor como al funcionamiento en estado estacionario.

This recording provides an overview of common different thrust bearing arrangements, with end play guidance tips for each.

Concentric to lap winding conversions are common practice in many EASA service centers. For most stators, this change is feasible and can be made with little difficulty. In some cases, however, it can be quite challenging and result in undesired outcomes due to reduction in copper or insulation.

Las conversiones de devanados concéntricos a imbricados son una práctica común en muchos centros de servicio de EASA y en la mayoría de los estatores, este cambio es factible y se puede realizar sin dificultad. Sin embargo, en algunos casos, puede resultar muy complicado y generar resultados no deseados debido a la reducción del cobre o la pared de aislamiento.

The video provides a comprehensive guide on performing a single-phase rotor test on a three-phase squirrel cage motor to check for open rotor bars.

From the manufacturer’s perspective, a random-wound, 2300-volt motor represents a substantial reduction in manufacturing cost. For the service center, the challenge is to successfully rewind them while providing a reliable repair. Here are some techniques which will enhance your success rate.