Technical Specifications
| Parameter | Value |
|---|---|
| Product Model | 6EP1961-2BA21 |
| Manufacturer | Siemens |
| Product Type | SITOP PSE200U 10 A Selectivity Module (4-Channel) |
| Input Voltage | 24 V DC (range 22–30 V DC) |
| Input Current | 40 A (max, at 24 V DC) |
| Number of Output Channels | 4 |
| Output per Channel | 24 V DC, up to 10 A (≤60 °C) |
| Output Voltage Formula | Vin – approx. 0.2 V |
| Adjustable Current Threshold | 3–10 A per channel (potentiometer) |
| Efficiency | ~99 % |
| Power Dissipation (rated) | ~10 W |
| Overload Capacity (input) | 35 V (momentary) |
| Channel Turn-On | Simultaneous or staggered via DIP (25 ms / 100 ms delay options) |
| Tripping Behavior | – Overcurrent shutdown: 1.0–1.5 × setting, ~5 s → off – Current limit: 1.5 × setting, ~100 ms – Immediate disconnect: Iout > setting & Vin < 15 V |
| Diagnostics per Channel | Tri-color LED (green = on, yellow = manually off, red = overcurrent off) |
| Signaling | Common signaling contact (changeover, 0.1 A / 24 V DC) |
| Electrical Connection | Screw terminals (0.5–16 mm² input +24 V; 0.5–4 mm² others) |
| Dimensions (W×H×D) | 72 × 80 × 72 mm |
| Mounting | DIN rail (TS 35), mounting height 180 mm |
| Spacing Required | 50 mm top/bottom, 0 mm sides |
| Protection Rating | IP20 |
| Operating Temp | –25 °C to +60 °C (natural convection) |
| Certifications | CE, UKCA, UL 2367, UL 508, EAC, CB, ABS, DNV |
| Weight | 0.22 kg |
| Origin | Austria (typical Siemens Amberg/AT production) |
Main Features and Advantages
Selective-island protection: The core value of the Siemens 6EP1961-2BA21 is that a fault on channel 3 doesn’t drag channels 1/2/4 down with it. In a typical S7-1500 cabinet where a single 20 A PSU feeds CPU, ET 200SP slices, PROFINET switches, and a valve terminal bank, a shorted solenoid on the valve branch would—without selectivity—either blow the PSU’s own overload or nuisance-trip a shared MCB, killing CPU and PROFINET in the process. The Siemens 6EP1961-2BA21 partitions those loads across four 10 A channels so the valve short only kills the valve branch; CPU and network stay up, and the HMI can still log the fault because its 24 V feed is on a different channel of the same Siemens 6EP1961-2BA21.
Adjustable 3–10 A threshold per channel: Every channel on the Siemens 6EP1961-2BA21 has its own front potentiometer. This matters because “10 A channel” doesn’t mean you want it fused at 10 A—a valve island with 8 × 0.7 A solenoids peaks around 5.6 A steady but can inrush higher on simultaneous shift; a sensor cluster with 30 × M12 prox devices maybe only draws 1.8 A total. Setting the Siemens 6EP1961-2BA21 channel pot to ~6 A for the valve island and ~3 A for the sensor cluster means a stalled solenoid trips in seconds, not instantly (the module does 1.0–1.5 × setting ≈ 5 s shutdown, 1.5 × setting ≈ 100 ms current limit), while a dead-short still gets the fast-limit. This dual-slope behavior is what “selectivity” actually means in 24 V DC distribution.
Tri-color LED per channel: Each of the four channels on the Siemens 6EP1961-2BA21 carries a three-state LED—green = output enabled, yellow = manually disabled (via remote-reset terminal or power-cycle logic), red = tripped by overcurrent. During a night-shift fault walkdown, a maintainer sees red on Ch2, knows exactly which branch to hunt, and doesn’t have to guess which of four blade fuses blew. That diagnostic clarity is why the Siemens 6EP1961-2BA21 displaces traditional fuse-holder strips in Siemens-native panels.
Common signaling contact + DIP staggered start: The Siemens 6EP1961-2BA21 offers a floating changeover contact (0.1 A / 24 V DC) that closes/pulls on any channel fault—wire it to a spare S7 DI and the HMI can show “24 V Branch Fault – Check PSE200U” without per-channel wiring. The DIP switch on the Siemens 6EP1961-2BA21 also selects how channels come up after 24 V restore: simultaneous, or staggered 25 ms / 100 ms delays. Staggered matters on big capacitor-input loads (long sensor homeruns, multiple switching regulators downstream)—simultaneous turn-on can create a cumulative inrush spike that falsely trips the Siemens 6EP1961-2BA21 thresholds or stresses the upstream PSU. Dialing “staggered” on the Siemens 6EP1961-2BA21 spreads that inrush across 100 ms.
Ultra-low drop, fanless, compact: Vin – 0.2 V at full load means the Siemens 6EP1961-2BA21 burns only ~10 W dissipation for a 4×10 A = 40 A throughput—99% efficient. No fan, no heatsink fins protruding, 72 mm wide, 0.22 kg. In a dense S7-1500 or S7-1200 panel where DIN real estate is fought over between PSU, breaker, PSE200U, BUFFER, REDUNDANCY, ET 200, and the CPU itself, the Siemens 6EP1961-2BA21 doesn’t punish the layout.
Certification breadth: UL 2367 (the 24 V DC control-circuit breaker standard) and UL 508, plus ABS/DNV marine, mean the Siemens 6EP1961-2BA21 clears both NFPA 79 machine panels and offshore skid BOMs. Panel builders doing multi-market machines (EU + NA + SEA) can standardize on the Siemens 6EP1961-2BA21 and not carry regional variants.
