What it is and what it does
The Siemens 3RT1025-3AP06-ZW98 is a SIRIUS power contactor in the S0 frame size, with three normally-open main contacts and screw-type terminals for the main current circuit. Rated operational current hits 10 A under AC-12 duty, which covers resistive loads like heaters or lighting banks — the typical non-inductive switching application for this contactor. For motor reversing or plugging duty (AC-4), it's rated 15.5 A at 400 V — that's the figure that governs stop-the-line cycle life on a conveyor or spindle drive. Auxiliary and control circuits use spring-loaded terminals, while the main power path lands on screw clamps — a hybrid termination scheme that speeds panel wiring on the control side without sacrificing high-current pull-down torque on the mains.
Mounting and integration — DIN rail fit
Fastens by screw or snap-on onto 35 mm standard mounting rail per DIN EN 50022, and side-by-side mounting is permitted — no mandatory gap between contactors on the rail. Dimensions are 65 mm wide, 85 mm tall, 91 mm deep, which puts it in the S0 footprint — fits the same gland-plate cutout as any S0 contactor in the SIRIUS family. Degree of pollution 3 means it's rated for industrial environments where conductive dust or occasional condensation is present — no extra conformal coating required inside a standard IP54 panel.
Termination and wiring
Main circuit screw terminals accept 2x (0.25–2.5 mm²) solid, 2x (1–2.5 mm²) stranded, 2x (2.5–6 mm²), or max 2x 10 mm² — covers common motor and heater cable sizes up to about 8 AWG. Auxiliary contact spring terminals accept 2x (24–14 AWG) — no screwdriver torque required on the control side, which shaves a few seconds per termination on a multi-contactor panel. Type 2 coordination (the stricter standard for motor starter protection) requires a 25 A gL/gG fuse upstream; Type 1 coordination allows a 63 A fuse.