Electricity and Control September 2022

DRIVES, MOTORS + SWITCHGEAR

Fast startup for asynchronous motors Johannes Happe, Product Manager Contactron, Phoenix Contact Electronics GmbH, Bad Pyrmont, Germany

Johannes Happe, Phoenix Contact Electronics.

Asynchronous motors are often supplied with overdimensioned frequency converters.This costs money and often time as well. In simple applications with just a few functions, a speed starter is ideal because, as the name suggests, its outstanding features include fast installation and startup.

Safe shutdown up to SIL 3 and PL e Thenewspeedstarter fromPhoenixContact’s Contactron product family provides a device class between motor starters and frequency converters. The compact solution, which offers intuitive operation, includes all the necessary functions – integrated in a single housing: direct start of asynchronous motors, reversing start, full motor protection, different speed settings, soft start and soft stop of the motor, and safe stop with safe torque off.

The new speed starters provide a device class between motor starters and frequency converters, to enable simple motor tasks.

I ndustrial plants usually incorporate a large number of electric motors. Most of the motors perform simple tasks: they need to transport objects or liquids from one place to another or execute the corresponding processing steps. Many such tasks are performed in logistics centres and on machines and systems. There are different ways of starting and operating a motor. These days, frequency converters (FCs) are used for most applications – especially if different speeds or soft starts are required. Frequency converters are complex devices that handle numerous functions, but they are often overdimensioned. At present, the applica tions where they are most commonly used typically involve simple tasks that require only two fixed speeds and/or a ramp function with a soft start and soft stop of the motor.

The device offers a number of advantages for the user, especially safe shutdown up to safety level SIL 3, PL e, and Cat. 4 with the built-in safe torque off (STO) functionality. The compact housing dimensions with an overall width of just 35 mm provide space savings in the control cabinet. In addition, easy wiring and an intuitive operation concept allow for quick installation and startup. Hence, the speed starter from the Contactron product family provides a cost-effective solution that includes all the necessary func tions for various speeds and soft start. In the most common applications, it must be possible to shut down rotating and moving parts safely via an emer gency stop switch, if parts become jammed, for example, or if there is an emergency situation. However, a fault must not result in the loss of safety, which is why the machine or system must have a redundant design. This can be achieved directly with the Contactron series speed starter. An additional contactor is therefore not required for safe shutdown of the motor. There is also the option on the con troller side to perform a two-channel shutdown via connec tions STO+ and STO-. The Contactron speed starter thus achieves safety categories SIL 3, PL e, and Cat. 4, all in a small installation space. Quick startup When constructing machinery and systems, time is a cost factor: the easier and quicker it is to install the application, the lower the financial outlay for the machine manufacturer and the more competitive the solution will be. The speed starters from Phoenix Contact enable startup to be com pleted in less than a minute. To get the motor running, the user needs only to wire the load input and output, and ap-

The Contactron speed starter and its main functions.

10 Electricity + Control SEPTEMBER 2022