What this part is and where it fits
The Siemens SIRIUS 3RT1016-2HB42-ZX95 is a power contactor in the compact S00 frame size, designed for switching motor loads in control panels. It mounts via screw or snap-on onto a 35 mm standard mounting rail per DIN EN 50022, making it a direct fit for any DIN-rail enclosure. The 24 V DC coil draws 2.3 W during both closing and holding, so the control transformer or power supply needs to budget for that steady-state load — no inrush spike beyond the closing transient. Rated for AC-3 duty at 4.5 kW on 400 V and 5.5 kW on 690 V, this contactor handles typical three-phase induction motors in that power band. The AC-4 rating of 8.5 A at 400 V covers plugging and inching applications where the contactor makes and breaks stalled-rotor current.
Key ratings and what they mean for fit
The spring-loaded terminals on the main current circuit accept 2x (0.25 to 2.5 mm²) solid or stranded wire, or 2x (24 to 14 AWG). That covers most panel wiring up to the 20 A fuse required for Type 2 coordination — no lug crimping needed. IP20 on the front and at the terminals means the contactor is protected against finger contact but not against moisture ingress — it belongs inside a sealed enclosure, not in a washdown zone. Operating temperature spans -25 to +60 °C, with pollution degree 3 (conductive pollution expected). That suits most industrial control rooms and switchgear cubicles without derating, though mounting side-by-side without spacing (allowed per the listing) will raise the local ambient — factor that into the thermal budget. Maximum operating altitude of 2 000 m covers the vast majority of installations; above that, dielectric strength and cooling derate per IEC 60947-1.
Lifecycle and sourcing posture
The SIRIUS platform has a published lifecycle roadmap, so the 3RT1016 family is a safe choice for designs that need to stay supportable through the next decade.
Integration notes for the panel builder
Width 45 mm, height 60 mm, depth 73 mm — the S00 footprint leaves room for auxiliary contact blocks or a solid-state overload relay on the same DIN rail segment. Side-by-side mounting is permitted, so you can gang multiple contactors without the 6 mm side clearance that larger frames require. Type 2 coordination requires a gL/gG 20 A fuse upstream; Type 1 coordination allows a 35 A fuse. The contactor itself has a mechanical endurance of 30 million operations, so it outlasts most load-side components in cyclic duty.