The Siemens 6EP1961-2BA11 is a SITOP buffer module that takes a 24 V DC input (22-30 V range) and delivers four controlled DC voltage outputs, each at Vin minus roughly 0.2 V. Rated efficiency hits 97 %, which means minimal heat loss in the enclosure — important when you're stacking modules in a confined DIN-rail row and relying on natural convection cooling over the -25 to +60 °C operating range. The four outputs each have a screw terminal accepting 0.5-4 mm² wire. An integrated current limitation trips at 1.5× the set value (typ. 100 ms), while an overcurrent protection circuit switches off after roughly 5 seconds at 1.0-1.5× set current. A non-electrically isolated remote reset input (24 V, high above 15 V) lets a PLC or safety relay re-enable the outputs after a fault clears.
The enclosure measures 72 mm wide, 80 mm high, and 72 mm deep — a compact footprint that occupies three standard DIN-rail TE (1 TE = 18 mm). Mounting height is listed at 180 mm, which accounts for the required clearance above and below for wiring and airflow. IP20 rated, so it's intended for dry indoor cabinets only — no washdown, no dust ingress protection. The screw terminals on the input side accept 0.5-16 mm² (for the +24 V) and 0.5-4 mm² (for the 0 V), which covers most control-circuit wiring sizes up to about 6 AWG.
Safety certifications stack up: UL-Recognized per UL 2367 (File E328600), cULus-Listed per UL 508 and CSA C22.2 No. 107.1 (File E197259), plus CE, EAC, and shipbuilding approvals from DNV GL and ABS. Emissions meet EN 55022 Class B (residential/commercial limits), immunity meets EN 61000-6-2 (industrial environment). Safety construction follows EN 60950-1 and EN 50178. MTBF is 755,915 hours at 40 °C — roughly 86 years of continuous operation. Storage and transport temperature range is -40 to +85 °C.