Allen-Bradley X42405 R.H. Thermal Overload Relay

Allen-Bradley X42405 R.H. Thermal Overload Relay is a size-3, right-hand overload accessory for Allen-Bradley contactors. Labeled Type B3, this unit provides thermal overload protection in motor-control circuits by monitoring current and interrupting the circuit when an overheating condition is detected, helping safeguard motors from damage in standard starter configurations. This is a legacy component and has been discontinued by the manufacturer, according to distributor listings, so it is typically encountered in existing installations or in stock for maintenance of compatible assemblies rather than as a current catalog item. The relay is designed to mate with compatible Allen-Bradley size-3 contactors, enabling integrated protection without modifying the control scheme. Because of its right-hand orientation and compact form, the X42405 is most commonly found in older control panels where exact X-series parts are required to preserve fit and wiring layout. If evaluating replacements, confirm that any alternative overload relay matches the same size-3 footprint and Type B3 designation to ensure proper mounting and electrical compatibility with the original starter.