Product Overview

The Siemens 6EP1332-2BA20​ is the entry-capacity member of Siemens’ SITOP PSU100S family—a 60 W, 24 V DC / 2.5 A primary-switched stabilized power supply built for DIN-rail mounting in industrial control cabinets where a compact, cost-effective, and certification-heavy 24 V rail is needed to feed PLC I/O, analog transmitters, valve positioners, encoder electronics, and DCS aux loads. Rated for single-phase 120/230 V AC auto-ranging input (50/60 Hz, TN/TT networks per VDE 0100 / IEC 364-3), the Siemens 6EP1332-2BA20​ delivers a floating (SELV) +24 V DC output that is short-circuit-proof, no-load-proof, and adjustable from 22.8 V to 28 V via an on-board potentiometer—handy when the cabinet’s 24 V rail needs to be nudged up to compensate for cable volt-drop across a long marshalling run to a field junction box.Positioned as the “light-duty workhorse” of the SITOP lineup, the Siemens 6EP1332-2BA20​ sits below the PSU300S (which adds selective fuse monitoring and wider-range input) and the newer PSU6200 (IO-Link enabled), but for the vast majority of S7-300/400 cabinets, ET 200 distributed nodes, SICOMP aux supplies, and Teleperm M / SPPA-T3000 24 V aux rails, 60 W is exactly the right size: enough for 8–12 analog transmitters plus a handful of DI/DO modules, without over-speccing the cabinet depth or the branch MCB budget. The unit is IP20, Protection Class I, 35 mm DIN-rail form factor, with screw terminals accepting 0.5–2.5 mm² conductors, a green “24 V OK” LED, and a normally-open relay contact (60 V DC / 0.3 A) that can drive a PLC DI or a cabinet alarm beacon when the output falls out of regulation—an often-underused but valuable feature for predictive maintenance.Certifications are where the Siemens 6EP1332-2BA20​ punches above its price: CE, UL 508 / CSA C22.2, cULus, DNV GL (maritime), and ATEX / IECEx Ex nA nC IIC T4 Gc for Zone 2 / Division 2 hazardous-area installations when mounted inside an IP54+ enclosure. Combined with >180 000 hour MTBF, –25 °C to +60 °C operating range (derated above +60 °C to +70 °C), and 85 % typical efficiency at rated load, the 6EP1332-2BA20 is the unit-spec default for EPCs who need one 24 V supply SKU to cover general-purpose cabinets, skid-mounted panels, and light process enclosures without opening a separate hazardous-area BOM line.

Technical Specifications

Main Features and Advantages

60 W compact footprint with 85 % efficiency.​ The Siemens 6EP1332-2BA20​ is sized for the “one-slot” feeling on a 35 mm DIN rail—narrow enough that three of them fit side-by-side in a 200 mm wide micro-cabinet, yet 60 W is enough to run a typical S7-314 CPU + 16-DI + 16-DO + 4 analog transmitters without breathing hard. At ~85 % efficiency the unit dissipates only about 10 W at full load, keeping the cabinet’s internal ambient from ratcheting up—important in sealed enclosures on skid packages where the only cooling is convection through the vent strips.Adjustable 22.8–28 V output via on-board potentiometer.​ While most plants run PSU100S at the default 24.0 V, the trim pot on the Siemens 6EP1332-2BA20​ exists for a reason: a cabinet feeding 4–20 mA transmitters on a long home-run to a tank farm may drop 0.8 V across the marshalling and field cable. Rather than upsizing the cable, bump the PSU to 25.5 V at the source—the transmitter still sees ≥23.6 V at the tail, keeping it in its 24 V ±10 % operating window. The pot is a small slotted brass screw accessible through the front vent; Siemens warns (and the Siemens 6EP1332-2BA20​ labeling echoes) not to adjust it in explosive-atmosphere conditions, but for normal cabinets it’s a five-second tweak with a screwdriver.Green LED + relay-contact “24 V OK” signal.​ A detail many plants under-use: the front green LED is obvious, but the hidden value is the NO relay contact rated 60 V DC / 0.3 A. Wire that contact to a spare DI on the PLC, or to a cabinet-alarm annunciator, and the PLC can detect “PSU lost regulation” before the 24 V rail collapses far enough to drop I/O. In a cabinet where the Siemens 6EP1332-2BA20​ feeds safety-relevant loops (ESD valve solenoids, fire-pump start permissives), that relay contact becomes part of the monthly proof-test checklist—if the DI doesn’t see “24V OK” at power-up, the tech knows the PSU is limping before the valves start misbehaving.150 % overload for 5 seconds per minute + parallel capability.​ The Siemens 6EP1332-2BA20​ is specified to deliver 3.75 A (150 % of 2.5 A) for 5 s out of every 60 s—designed for inrush scenarios like capacitive loads on analog transmitters all powering up together, or a small motorized damper actuator that briefly draws 3 A on stall. For applications needing a bit more headroom without jumping to the 5 A sibling, two 6EP1332-2BA20 units can be paralleled (up to 2 units) for current sharing, giving 5 A total with rudimentary redundancy. It’s not a true redundant topology (no decoupling diodes built in; Siemens recommends external OR-ing if N+1 is required), but for non-safety skids it’s a cost-effective way to get 5 A from two 60 W units instead of one 120 W.Short-circuit proof with constant-current characteristic.​ On a sustained short (tech drops a screwdriver across the 24 V terminals—yes, it happens), the Siemens 6EP1332-2BA20​ folds back to a constant ~3.4 A, then into hiccup until the fault clears. Typical short-circuit delivery is ~9 A for 100 ms at startup or 800 ms during run, then current-limits. This protects both the PSU and the wiring (the recommended branch protection is a 3 A C-curve MCB per IEC 898, with an internal T 3.15 A / 250 V input fuse that is not user-replaceable—so the MCB is the serviceable element). For cabinets where “someone will eventually short something” is a given, this behavior keeps the PSU alive through the tech’s mistake.Certification breadth for a 60 W unit.​ The Siemens 6EP1332-2BA20​ carries ATEX / IECEx Ex nA nC IIC T4 Gc (Zone 2 / Div 2) when installed inside an IP54+ enclosure, plus DNV GL for marine/offshore topsides, plus UL 508 and CSA for North American panels. For EPCs doing multi-region projects, specifying the 6EP1332-2BA20 means one BOM line works in a German chemical plant, a Gulf Coast refinery skid, and a North Sea platform utility cabinet without splitting into regional variants. That’s why the model shows up in so many standard “cabinet-builder kits” from the big system integrators.