What it is and what it tells you
The Siemens 3UF7124-1BA01-0 is a SIRIUS current/voltage measuring module that monitors line-to-line voltages from 110 V to 690 V AC at 50 or 60 Hz. It reports current, voltage, frequency, and power consumption, with energy measurement accuracy of ±5 % under defined conditions (47–1260 A, cos φ 0.5–1, 25 °C). That's good enough for trending and submetering, not for utility billing.
Mounting and wiring – checklist
Direct-mount or stand-alone installation; any orientation works. The module is 145 mm wide, 147 mm high, 148 mm deep. Keep 30 mm clearance top and bottom, 0 mm left and right – flush-to-DIN end plates are fine. Terminals accept solid wire 0.5–4 mm² or two 0.5–2.5 mm²; AWG equivalents are 20–12 solid, 20–14 stranded. IP00 means open-style; keep it inside a panel or enclosure. Ambient operating range is –25 to +60 °C, storage and transport –40 to +80 °C. The altitude derating kicks in above 2 000 m: at 3 000 m limit ambient to +50 °C (no protective separation), at 4 000 m limit to +40 °C. Ignoring that derating voids the thermal protection curve.