DC-input power supply with NEC Class 2 output
The Siemens 6EP3322-6SB10-0AY0 is a SITOP PSU6200 power supply that accepts a DC input from 110 to 300 V and delivers a rated output of 4 A, with a maximum of 5 A. The output is NEC Class 2 compliant per UL 1310, meaning it's limited in power and current — suitable for powering field devices, sensors, and PLC I/O in dry, indoor panels where the Class 2 rating avoids the need for metallic conduit or other overcurrent protection measures downstream. Rated range is 0 to 4 A, but above +55 °C ambient the unit derates at 2% per K up to +70 °C — so at 60 °C you lose about 10% headroom, leaving roughly 3.6 A usable. The internal fuse protection handles fault clearing without an external MCB in most cases, though the feeder recommendation calls for a 10 A B-curve or 6 A C-curve breaker upstream.
Snaps onto DIN rail EN 60715 35×7.5/15. The 20 mm clearance required above and below is for natural convection cooling — don't box it in tight.
MTBF at 40 °C is 2,566,680 hours — roughly 293 years — which is a calculated figure under ideal conditions, but it tells you the design is solid for continuous-duty applications like a brewery line or a conveyor system running 24/7.