Allen-Bradley 810-A20A Magnetic Overload Relay

Allen-Bradley 810-A20A Magnetic Overload Relay is a magnetically operated motor protection device from Rockwell Automation’s Bulletin 810 family, designed to work with a compatible motor starter to safeguard motors from overload conditions. The 810-A20A is part of the classic 810 series and is specified with a maximum voltage rating up to 600 V, with some historical listings noting a 600 VDC capability and a continuous current rating around 130 A, making it suitable for larger motor loads in industrial control panels. As a dedicated overload protection relay, it provides magnetic tripping to interrupt the circuit when an overload is detected, helping to prevent motor damage and extend equipment life. Typical applications include incorporation into motor control circuits where robust, field-replaceable protection is desired in manufacturing or process environments, often alongside contactors and other protection components in assembled starters. This model represents a vintage yet enduring solution in Allen-Bradley’s motor protection lineup, offering the reliability of a long‑standing overload relay design for users seeking a proven protective device within legacy or retrofit control systems.