System Optimizes Performance of Low-Voltage Motor Management

Schweitzer Engineering Laboratories, Inc. (SEL) has introduced a comprehensive, centralized control system that monitors, controls and protects low-voltage motor control systems. Scalable to any size motor control center (MCC), motorMAX™ is a turnkey system that ships to customers fully configured, tested and ready for immediate assembly into MCCs. High-speed arc-flash mitigation technology comes standard in the motorMAX. The system detects arc-flash events and trips upstream breakers to protect personnel.

“We have leveraged SEL’s time-proven power system protection technology to bring smart motor controls to a whole new level,” said Scott Manson, P.E., Engineering Services technology director. “With motorMAX, SEL has completely eliminated programmable logic controllers (PLCs) and as a result has greatly simplified motor management.”

“Arc-flash detection and mitigation are effective methods for reducing incident energies in old MCC gear,” said Manson. “motorMAX is a low-cost alternative to replacing existing MCC line-ups while still allowing users to keep up with modern safety requirements.”

Another safety feature of the motorMAX is its remote human-machine interface (HMI), which allows operators to control motors from a safe distance. The HMI displays warnings, alarms and status indication signals to maintenance and process personnel. To assist in troubleshooting and diagnosing fault events, the system automatically collects time-synchronized Sequence of Events (SOE) records and COMTRADE oscillography in the SEL-849 Motor Management Relay, a standard component of the system. Time synchronization between the relays is accomplished via the Simple Network Time Protocol (SNTP). A standard Modbus® interface allows process control systems remote status and control of MCCs. A typical round-trip time for controlling a motor contactor is 100 ms and can be faster.

“motorMAX customers don’t need to enter any relay or controller settings because all devices come pre-configured and tested,” Manson said. “That saves our customers hundreds of hours of engineering labor for a typical MCC and translates into better quality and lower risk for MCC purchasers.”