The Siemens 5SL4314-7 is a SENTRON miniature circuit breaker (MCB) with a 3-pole, C-curve trip characteristic rated at 0.3 A at 400 V AC.
At 0.3 A, this is a low-current branch breaker, not a main feeder device. Rated current derates with ambient temperature: 0.3 A at 30 °C, 0.28 A at 40 °C and 45 °C, and 0.26 A at 55 °C. If the panel runs hot, the breaker will carry less before tripping — factor the actual enclosure temperature into the load calculation.
Snap-on DIN-rail mounting, any position. Installation depth 70 mm; overall depth 76 mm — leaves clearance for wiring behind the DIN rail. Sealable with a lead seal to prevent tampering. Touch protection on the terminals is standard for safe handling during commissioning.