The Siemens SITAS 4AM4042-5AN00 is a 250VA safety isolating control transformer converting a 400V primary supply to a 24V secondary at 10.4A. It is designed for European industrial panels where 24VDC control circuits are powered from the 400V three-phase mains via a transformer and rectifier, providing SELV-level safety for PLCs, relays, and HMI components.

Electrical Performance

Built on the EI 96/58 laminated core with 89% efficiency, it delivers an 850VA short-time (S6) rating — 3.4× the continuous rating — to handle high-inrush loads without voltage sag. Primary taps at 380V, 400V, and 420V (±5%) accommodate grid voltage variation across different sites. The II0 vector group ensures galvanic isolation between primary and secondary.

Control Circuit Integration

The 10.4A secondary current supports extensive control circuits with multiple contactor coils, relay banks, PLC I/O modules, and HMI panels. Combined with a rectifier, it forms a reliable 24VDC power supply backbone for machine control systems.

Construction & Certifications

IP00 open-frame, 98×106×118mm, 4.6kg. Screw or DIN rail mounting with screw-type and tab terminals. Certified to EN 61558-2-2 and EN 61558-2-6 with CE, cRUus, and EAC approvals. Class B insulation for 40°C ambient.