It mounts directly onto a contactor (fastening method: contactor mounting) and protects against overload and phase failure by tripping the contactor coil when the motor current exceeds the set threshold for too long. That covers most pump, fan, and conveyor applications without nuisance tripping.
Size S00 footprint: 45 mm wide, 87 mm tall, 78 mm deep. Mounting clearances are tight — zero clearance upwards, forwards, and backwards, 6 mm at the side. That means you can pack relays side-by-side on the DIN rail without extra spacing, but leave the 6 mm side gap for airflow and wiring access. Main circuit terminals accept solid or finely stranded wire: 2× (0.5…1.5 mm²) and 2× (0.75…2.5 mm²), plus AWG equivalents 2× (20…16) and 2× (18…14). Auxiliary/control circuit terminals take 2× (0.5…1.5 mm²) and 2× (0.75…2.5 mm²) or AWG 2× (20…16) and 2× (18…14). All screw-type — no special tooling needed.
The built-in auxiliary contacts (normally open and normally closed) are rated for switching: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V, plus 0.22 A at 110 V or 125 V, and 0.11 A at 220 V. These are the contact ratings for the signal circuit that feeds the contactor coil or a PLC input — keep the load within these limits to avoid welding the contacts.