Contactor relay, size S00, 4 NO, 24 VDC — panel fit and switching capacity
The Siemens 3RH2140-1BM40-ZW97 is a size S00 contactor relay with four normally-open instantaneous contacts and a 24 VDC coil rated at 4 W closing and holding power. It mounts via screw or snap-on onto a 35 mm DIN rail, occupying 45 mm of panel width at 73 mm depth. The DC switching capacity is specified per voltage: 10 A at 24 V, 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, and 0.26 A at 600 V. For AC circuits the relay handles 10 A at 230 V and 400 V, 3 A at 400 V, and 1 A at 690 V. The arcing time runs 10 to 15 ms, and the mechanical service life is rated at 30 million operating cycles. Pollution degree 3 per IEC 60947-1 means the contactor relay is rated for industrial environments where conductive pollution occurs or dry non-conductive pollution may become conductive due to condensation. The surge voltage resistance is 6 kV, confirming suitability for 400 V line-to-line circuits with adequate clearance.
Mounting and clearance — DIN-rail integration
Mounting position is flexible: the relay can be rotated ±180° on a vertical surface and tilted forward or backward by ±22.5°. Required clearances to adjacent components: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm at the side. These clearances must be maintained for proper arc quenching and heat dissipation. Wire termination accepts 2 × (0.5 to 1.5 mm²), 2 × (0.75 to 2.5 mm²), or 2 × 4 mm² solid or stranded conductors; AWG equivalents are 2 × (20 to 16), 2 × (18 to 14), or 2 × 12. The fastening method is screw and snap-on onto 35 mm DIN rail.