The Siemens 6ES7307-1EA80-0AA0 is a S7-300 series power supply module that delivers a rated output current of 5 A, with a rated range of 0 to 5 A. It accepts two AC input voltage ranges: 93 to 132 V (120 V nominal) and 187 to 264 V (230 V nominal), at a line frequency of 47 to 63 Hz. This is the power supply that feeds the S7-300 backplane and any connected I/O modules — the one that keeps the rack alive. Mounts directly onto the S7 rail, so it snaps into the standard S7-300 rack without extra brackets. The 5 A rating means it can power a moderately loaded rack — think a CPU plus a handful of digital and analog I/O modules. If your BOM calls for more than 5 A total backplane draw, you need a higher-rated supply or a second unit.
It auto-selects between the two ranges (93–132 V and 187–264 V) via a selector switch on the device. If your panel is wired for 120 V, set it to the low range; for 230 V, the high range. Miss that switch and the supply either won't start or lets the magic smoke out. The internal fuse is a T 3.15 A/250 V, not user-accessible — if it blows, the unit is scrap. Galvanic isolation is rated as safety extra-low voltage (SELV) output per EN 60950-1 and EN 50178, with creepage distances and clearances greater than 5 mm. That means the 24 VDC output is isolated from the mains, which is standard for PLC power supplies but worth noting if you're feeding sensitive analog circuits — the isolation keeps line noise off the backplane. IP20 protection class means it's for use inside a closed control cabinet only — no washdown, no dust ingress protection.
Carries CE marking, UL listing (UL 508, File E143289), CSA approval (CSA C22.2 No. 142), and EAC approval. No ATEX, IECEx, DNV GL, FM, or UL hazardous location approvals — so not rated for explosive atmospheres or marine environments. The recommended feeder protection is a miniature circuit breaker: 10 A characteristic C or 6 A characteristic D.
Output connections: L+ and M each have three screw terminals for the same wire range — the three terminals per pole let you daisy-chain the 24 VDC to multiple modules without a separate distribution block. The I²t value is a maximum of 1.8 A²·s — that's the energy let-through before the internal fuse opens. Not something you size by, but useful if you're calculating coordination with the upstream breaker. Typical no-load current draw is 0.3 mA; maximum is 3.5 mA.