Allen-Bradley 800MR-A4A USNT Motor Overload Relay

Allen-Bradley 800MR-A4A USNT Motor Overload Relay is a compact overload protection device in the 800MR family, designed to be used with compatible Allen-Bradley motor starters to guard motors in industrial control panels. The A4A suffix denotes this particular variant, and the USNT listing confirms its acceptance for use in US market installations under applicable safety standards. As a dedicated overload relay, it sits in series with the motor starter circuit to monitor current conditions and trip to disconnect the motor when an overload event is detected, helping prevent motor damage, electrical fires, and unplanned downtime. The model number 800MR-A4A identifies the exact configuration for ordering and cross-compatibility with compatible pushbutton/starter assemblies within the Allen-Bradley ecosystem. Typical applications include conveyors, pumps, fans, and other equipment where motors require reliable protection within a starter that uses Allen-Bradley components. For procurement and installation, verify compatibility with your existing 800MR pushbutton assemblies and ensure the USNT listing applies to your local code requirements; exact electrical ratings and mounting configurations are specified in the official product documentation from Rockwell Automation and in distributor catalogs.