The Siemens SITAS 4AM5542-5AD40 is an 800 VA control transformer — the mid-range workhorse for industrial control panels that have outgrown the 500 VA class. With a massive 3,400 VA short-time (S6) rating — over 4× the continuous rating — it handles the simultaneous pull-in of multiple large contactors, motor starters, and solenoid valves without voltage dip. The dual 2×115 V secondary can be series-wired for 230 V (3.48 A) or parallel-wired for 115 V (6.96 A), providing native compatibility with both IEC and NEMA control circuit standards. The EI 150/65 core in a 152 × 144 × 126 mm package at approximately 12.6 kg reflects the substantial magnetic capacity needed for reliable 800 VA continuous output. At 93% efficiency, it operates cooler and with lower lifetime energy cost than the smaller-frame SITAS models.

Key Features

• 800 VA continuous, 3,400 VA S6 — over 4× short-time capacity
• 400 V ±5% primary (380/400/420 V) — three taps for voltage matching
• Dual 2×115 V secondary — series (230 V) or parallel (115 V) configuration
• 93% efficiency — significant improvement over smaller-frame models
• EI 150/65 core — larger iron cross-section for high-power handling
• IP00, 152 × 144 × 126 mm, screw mounting, UL/CSA recognized

Technical Data

Applications

Medium-to-large machine control panels: motor control centers with multiple DOL starters, packaging machine control systems with numerous pneumatic solenoid banks, printing press auxiliary circuits, and CNC machine tool control cabinets. The 800 VA rating comfortably powers 10–15 contactor coils or a large distributed control relay network. For OEMs exporting to both IEC and NEMA markets, the dual secondary eliminates the need for separate transformer variants.