The Siemens 3RB1016-2PB0 is a solid-state overload relay rated for 1.5...6.0 A, class 20, in the size S00 frame. It mounts directly onto a contactor and uses screw terminals. The manual-automatic reset mode gives the commissioning engineer a choice: manual reset for fault investigation on a line, or automatic reset for remote or unattended installations where a momentary overload trip can self-clear.
The 1.5...6.0 A range covers small motor loads — fractional-horsepower pumps, fans, conveyors — where a bimetal relay would drift with ambient temperature. Solid-state construction eliminates that drift, so the trip curve stays repeatable across the panel's internal temperature rise. Class 20 means the relay allows a 600% overload for up to 20 seconds before tripping, which matches standard NEMA motor starting profiles for general-purpose induction motors. The size S00 footprint is the smallest Siemens contactor-mount frame; it fits directly onto S00 contactors without a separate adapter plate, saving DIN-rail space in a crowded enclosure.