Motor soft starters: Less space on control panels, other installations

By Control Engineering Staff February 27, 2007
ABB’s new PSR model soft starters are extremely compact in applications, saving space on control boards for machine builders.

Wichita Falls, TX ABB’s new PSR model soft starters offer users a full set of knob-adjustable functions for starting and stopping 3 to 45 A, three-phase motors, up to 600 V ac all in a compact package that easily mounts in small control panels and equipment enclosures. The idea of soft starting motors is popular with end users who want to improve equipment design reliability by eliminating the stress on drive train components typical with full voltage starting methods. Applications where drive train reliability is critical include pumps, fans, mixers, and crushers. Reduced voltage starting is important in conveyor applications where any initial start-up jolt would break fragile product or create a safety hazard; in people movers like escalator, elevators, and moving walkways.

“This smaller size provides cost savings for custom panel and industrial equipment designs, both as a product, and in the real estate it frees up to panel builders for other uses,” says Lorenz Eggenschwiler, product marketing, ABB Low Voltage Products & Systems. “The PSR offers a very small footprint solution for machine designers where installation space must be reduced.”

The PSR range includes three physical sizes, with widths from 1.77-2.13 in. (45-54 mm), covers rated currents from 3 to 45 A, up to 600 V ac, and is available for control voltages of 24 V dc or 100-240 V ac. All sizes include a “run” signal relay, while sizes from 25 to 45 A add a signal relay for “TOR” or full voltage. These can be attached to an automation control system to provide closed-loop control or operator indication. The wider operating voltage range of the PSR also “provides a reduction in the cost of back-up inventory required to support multiple OEM equipment manufacturing applications,” says Eggenschwiler; “less inventory, but more range.” It also can reduce inventory needed for maintenance-critical, 100% uptime, municipal- and process-control applications, he adds.

The new soft starter family has a clearly marked front panel with knob adjustments for the three operational settings (no programming is required). The connection terminals are clearly marked and an installation diagram is included to allow easy, fast, positive mounting and connection. The enclosure can be DIN-rail or screw mounted. FieldBusPlug accessories are available for several protocols, including Profibus DP and DeviceNet. The PSR soft starter range has been tested and approved for UL and CCC, includes the CE logo, and meets RoHS directives.

Learn more about soft-starting benefits in the Control Engineering article (with diagram): ” Starting, Stopping Motors Softly .”

—Control Engineering Daily News Desk
Edited by Mark T. Hoske , editor in chief