Arc-Flash Solutions


SEL combines light-sensing technology with fast overcurrent protection to provide high-speed arc-flash detection (AFD).


SEL arc-flash detection technology significantly decreases the time it takes a relay to trip in response to an arc fault, which reduces hazardous arc-flash incident energy. SEL combines light-sensing technology with fast overcurrent protection to provide high-speed arc-flash detection (AFD). Combining these technologies allows high-speed tripping during arc-flash events without overtripping for external faults.


SEL's cost-effective arc-flash detection technology reduces arc-flash-related equipment damage for standard and arc-resistant switchgear in medium- and low-voltage applications. Arc-flash detection comes standard in the SEL-849 Motor Management Relay and is available as an option for the SEL-710-5 Motor Protection Relay as well as the SEL-751 and SEL-751A Feeder Protection Relays.


Combine the power of SEL's MotorMAX® smart motor control center solution with the safety of our integrated, secure arc-flash protection for improved plant safety and performance. MotorMAX® is a smart, centralized motor control system that gives you the information to make informed decisions about your processes. And the SEL-849 motor management relay in MotorMAX® uniquely integrates arc-flash detection at no additional cost, providing overcurrent supervised arc-flash mitigation, which reduces incident energy in the affected area and reduces hazardous working conditions for personnel. In an arc-flash event, MotorMAX® can shorten out-of-service time, reduce equipment damage, and allow you to get back into service quickly.

Reduced Damage to Switchgear—With arc-flash hazard protection, equipment damage is minimized during an arc-flash event, returning affected equipment to service faster and maximizing power system availability.

Coordinated Protection—Use SEL Mirrored Bits communications or IEC 61850 GOOSE messaging to coordinate upstream protection if a fault occurs. In some situations, it is necessary to send a transfer trip signal to an upstream breaker relay to clear an arc fault.

Flexible Installation—Install into new switchgear or motor control centers. Retrofit into existing equipment with optional mounting kits. Upgrade your SEL-751 Relays with a field-installable arc-flash detection upgrade kit.

Substation Ethernet—The SEL-751A withstands electrostatic air discharge of 15 kV and communicates via Modbus TCP, DNP3 LAN/WAN, Telnet, FTP, and IEC 61850.

Quality, Reliability, and Service—SEL products operate in a temperature range of –40º to +85ºC and are backed by our ten-year, worldwide warranty.


High-Speed Detection—Arc-flash light sensing and overcurrent protection detect arc-flash hazards and send a trip signal to the breaker in as fast as 2 ms.

MotorMAX® Arc-Flash Protection

To validate the arc-flash detection performance of the SEL MotorMAX® smart motor control center solution, a series of tests were performed at a high current laboratory. This video shows the difference in arc flash intensity for the same test condition with and without SEL arc flash detection.

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