The Siemens SITAS 4AM3442-8JD40 is a 100VA single-phase control transformer with a three-tap primary accepting 400V, 385V, or 245V AC supply voltages. Its dual 115V secondary windings can be wired in series for 230V at 0.435A or in parallel for 115V at 0.87A, providing flexibility for control circuits designed for either voltage standard. The EI 84/42 laminated core delivers 86% efficiency with Class B insulation rated for 40°C ambient operation.

Three-Tap Primary for Multi-Region Deployment

The discrete tap selection — 400V, 385V, and 245V — allows a single transformer model to accommodate different line-to-line and line-to-neutral supply configurations without stocking multiple single-voltage variants. This simplifies procurement for machine builders exporting equipment to regions with different industrial supply voltages. The tap terminals are clearly marked on the transformer faceplate for unambiguous field connection.

Dual 115V Secondary: Series or Parallel Operation

Connecting the two 115V secondary windings in series produces a 230V output at 0.435A for control circuits following IEC standard voltage conventions. Parallel connection delivers 115V at 0.87A — double the current — for markets where 115V control is standard. The 310VA S6 short-time rating (3.1× the continuous rating) provides ample surge capacity for contactor pull-in and solenoid actuation.