The Siemens SITAS 4AM2342-5AT10 is the 400 V-input variant of the 25 VA class — the smallest step-down control transformer in the SITAS range. It converts 400 V AC three-phase-derived single-phase mains to 230 V AC for powering individual control relays, miniature timers, or a single PLC power supply module. Three primary taps (380 V, 400 V, 420 V) provide ±5% adjustment to match actual site voltage and optimize secondary regulation. The EI 60/20 core in a 78 × 62 × 79 mm footprint at 0.82 kg makes it the most space-efficient choice for auxiliary control power in compact machine panels.

Key Features

• 400 V to 230 V step-down — powers standard control devices from industrial mains
• ±5% primary taps (380/400/420 V) for site voltage matching
• Smallest SITAS step-down model: 78 × 62 × 79 mm, 0.82 kg
• 50/60 Hz operation, IP00 open-frame
• Screw/tab terminals, screws or DIN rail mounting
• UL/CSA recognized

Technical Data

Applications

Compact machine control panels: individual relay coil power, miniature timer supplies, PLC CPU module auxiliary power, and single-sensor isolation in distributed I/O boxes. The 25 VA rating suits applications where only one or two small control devices need dedicated transformer-fed power.