Contact ratings and coil
The Siemens 3TX7130-0DD03 is a surface-mounted open power relay from the 3TX71 series, with a DPDT contact arrangement rated for 40 A at 48 V DC and 1/3 hp at 120 V AC. The coil pulls in at 48 V DC — verify your control bus can hold that without sag under load, especially if it's sharing a supply with contactors or solenoids in the same panel. Dielectric strength: 1,500 Vrms between contacts; 2,200 Vrms between coil and contact and between poles.
Durability and fit
Electrical endurance: 100,000 operations under load; mechanical endurance: 1,000,000 cycles. The relay mounts on a surface (panel or chassis) rather than a DIN rail — factor in the mounting plate and wiring access when integrating into an existing enclosure.