Power Supply Sizing and Fit
The Siemens 6EP1333-2BA01 is a SITOP power supply rated for 5 A continuous output, with a rated range of 0 to 6 A up to +45 °C. That means at typical 25 °C ambient you get the full 5 A, and you can draw up to 6 A if the cabinet stays under +45 °C — useful for intermittent loads or a short-term peak during startup. The input accepts 85 to 264 VAC (47 to 63 Hz), covering both 120 V and 230 V line supplies globally. Output is safety extra-low voltage (SELV) per EN 60950-1 and EN 50178, so it's suitable for powering 24 VDC control circuits, PLCs, sensors, and relays without additional isolation. The 50 mm width (Top: 50 mm, Bottom: 50 mm) fits standard DIN-rail enclosures — snaps onto 35x7.5/15 mm rail per EN 60715. Approvals include cULus (UL 508, CSA C22.2 No. 107.1), cCSAus (UL 60950-1, CSA C22.2 No. 60950-1, UL 1604), CE, EAC, and DNV GL — so it's accepted for industrial control panels, machinery, and marine applications. IP20 protection means it's intended for clean, dry indoor cabinets only.
The internal fuse is a T 3.15 A/250 V (not user-accessible). The recommended upstream protection is a miniature circuit breaker from 6 A characteristic C. MTBF at 40 °C is listed at 1,694,714 hours — roughly 193 years continuous, so field reliability is high. If you need a second-source or higher-current sibling, the 6EP1336-3BA00 is a 10 A unit in the same SITOP family — same DIN-rail footprint but wider (70 mm vs 50 mm). The 6EP1333-2BA01 is the 5 A narrow version; panel cutouts and wiring will differ.
Wiring and Connections
Output terminals: L+, M — two screw terminals each, same wire range. That gives you a daisy-chain point for distributing 24 VDC to multiple loads without an extra terminal block. The output voltage is set via a selector switch on the device (initial value set by switch). No potentiometer trim — it's a fixed tap, so confirm the voltage before powering the bus. Galvanic isolation between input and output is safety extra-low voltage (SELV) rated — output is floating relative to earth. This simplifies grounding in mixed-voltage panels: you can reference the 24 VDC common to PE or leave it floating, depending on your PLC and sensor requirements.