The Siemens 4AM6542-5AT10-0FA0 is a 2.5 kVA single-phase control transformer from the SITAS series, designed to step 400 V mains down to 230 V for industrial control circuits. The three-tap primary — selectable between 380 V, 400 V, and 420 V — accommodates regional voltage variations without compromising secondary accuracy, an advantage when panels are deployed across different facilities or countries with slightly different grid levels.

Electrical Performance

With a continuous rating of 2.5 kVA and a short-time surge capacity of 13.3 kVA under S6 duty, this transformer handles the high inrush demands of contactor coils, solenoid valves, and relay banks without voltage sag. Low switch-on inrush current reduces nuisance tripping of upstream circuit protection. Efficiency reaches approximately 96% at full load, with a relative short-circuit voltage of 1.6% ensuring stable secondary voltage under varying load conditions.

Construction and Compliance

Built on an EI 192/110 laminated core with electrically isolated windings, the unit operates with a 40 K temperature rise under Class B (130°C) insulation. It complies with EN 61558-2-1, EN 61558-2-2, and EN 61558-2-4, and is UL/CSA recognized for global deployment. The IP00 open-style design with screw/tab terminals is intended for installation within control cabinets, mounted via screw fixing on a chassis plate. Dimensions are 180 × 194 × 178 mm (H×W×D) with a net weight of approximately 28 kg.

Related Products in the SITAS Series

The 4AM6542-5AT10-0FA1 offers the same 400 V to 230 V rating with cage-clamp terminals for tool-free wiring. For other input voltages, the 4AM6542-5FT10-0FA0 (500 V), 4AM6542-8DD40-0FA0 (525/500/480 V multi-tap), and 4AM6542-5MT10-0FA0 (690 V) provide the same 2.5 kVA platform with different primary configurations.