Siemens 6EP1333-2BA01 Industrial Power Supply – SITOP PSU100S

Siemens 6EP1333-2BA01 SITOP PSU100S: Regulated 24 V DC / 5 A Single-Phase Industrial Power Supply for Automation Control Systems

The Siemens 6EP1333-2BA01 belongs to the SITOP PSU100S product family — a series of single-phase stabilized power supplies engineered specifically for industrial automation environments. Within a control cabinet, the PSU occupies the role of the primary DC bus source: it converts wide-range AC mains (85–264 V AC, 47–63 Hz) into a tightly regulated 24 V DC rail that feeds PLCs, distributed I/O nodes, HMI panels, solenoid valves, and field sensors simultaneously. The 5 A continuous output rating translates to a 120 W power budget, which is sufficient to sustain a mid-density SIMATIC S7-1200 or S7-300 rack with several analog and digital I/O modules under full load.

Unlike general-purpose SMPS units, the 6EP1333-2BA01 is designed around the electrical and mechanical constraints of IEC 61131-2 compliant PLC systems. Its output voltage is adjustable between 22.8 V and 26.4 V via a front-panel potentiometer, allowing field engineers to compensate for cable voltage drop across long 24 V distribution runs without introducing a separate voltage regulator stage. The unit mounts on a standard 35 mm DIN rail and occupies only 55 mm of horizontal panel width — a critical dimension in densely populated control enclosures where every millimeter of rail space carries cost.

The SITOP PSU100S line is a field-proven platform with documented MTTF exceeding 500,000 hours at 40 °C ambient, calculated per IEC 62380. This figure reflects the component derating strategy Siemens applies across the SITOP range: electrolytic capacitors are operated at significantly below their rated voltage and temperature ceiling, extending service life well beyond the typical 10-year panel lifecycle. For procurement engineers, this translates directly into reduced unplanned downtime risk and lower total cost of ownership over the asset’s operational period.

Real-time Stock & RFQ: [email protected] | WhatsApp: +86 18359268345

Technical Parameters

Hardware Logical Analysis

The 6EP1333-2BA01 is built on an active power factor correction (PFC) front-end followed by a resonant LLC half-bridge DC/DC converter stage. This two-stage topology is the reason the unit achieves ≥ 89% efficiency across the full input voltage range rather than only at a single operating point — a characteristic that matters in installations where mains voltage fluctuates between 85 V AC (brownout conditions in some Asian industrial zones) and 264 V AC (European 230 V with ±15% tolerance).

EMC Architecture: The input filter stage incorporates a common-mode choke, X-capacitors, and Y-capacitors arranged to suppress both differential-mode and common-mode conducted emissions below the EN 55011 Class B limit. This is a more stringent target than the Class A limit required for industrial environments, providing margin against interference coupling into adjacent PROFIBUS or PROFINET segments sharing the same cable tray. The output stage includes a π-filter (inductor + output capacitor bank) that reduces residual ripple to ≤ 150 mV peak-to-peak — well within the ≤ 5% ripple tolerance specified by IEC 61131-2 for PLC power inputs.

Thermal Management: The unit uses a natural convection cooling strategy with no internal fan. Heat is conducted from the primary switching transistors and output rectifier diodes through a copper heat spreader to the aluminum housing, which acts as a passive radiator. The absence of a fan eliminates the single highest-failure-rate mechanical component in a switching power supply, directly contributing to the >500,000 h MTTF figure. Derating begins at 60 °C ambient, with output current linearly reduced to 2.5 A at 70 °C — a behavior that prevents thermal runaway rather than triggering a hard shutdown that would interrupt the control system.

Output Capacitor Bank: The output capacitor bank is sized to deliver ≥ 20 ms hold-up time at full load and 230 V AC input. This 20 ms window is not arbitrary — it corresponds to one full cycle of a 50 Hz mains supply, ensuring the PSU bridges a complete mains half-cycle dropout without the output voltage falling below the 18 V DC minimum required by most SIMATIC CPU modules to maintain program execution and retain SRAM data.

Overload and Short-Circuit Response: Under overload conditions, the unit enters constant-current limiting mode, clamping output current at approximately 110–120% of rated current (5.5–6 A). If the fault persists and output voltage collapses below approximately 18 V, the controller transitions to hiccup mode — periodically attempting restart at reduced duty cycle. This behavior protects both the PSU and the wiring harness from sustained fault current while allowing automatic recovery once the fault is cleared, without requiring manual intervention at the panel.

System Integration Benefits

• Native SIMATIC Ecosystem Compatibility: The 24 V DC / 5 A output directly satisfies the power input specification of SIMATIC S7-300, S7-400, S7-1200, and S7-1500 CPUs, as well as ET 200M, ET 200S, and ET 200SP distributed I/O stations. No intermediate DC/DC converter or voltage regulator is required between the PSU output terminals and the PLC backplane power connector.
• Wide-Range Input Eliminates Dual-Voltage Stocking: A single 6EP1333-2BA01 unit operates correctly on both 120 V AC (North American) and 230 V AC (European/Asian) mains without any hardware modification. This eliminates the need to stock separate PSU variants for different export markets and simplifies spare-parts management for OEMs shipping machines globally.
• Deterministic Output Regulation for Analog I/O Accuracy: The output voltage regulation is ≤ ±1% from no-load to full-load, and ≤ ±0.5% for line variation across the full input range. For analog input modules (e.g., SM 331 or AI 8×U/I) that derive their reference voltage from the 24 V bus, this tight regulation directly reduces offset error in 4–20 mA and 0–10 V measurement chains without requiring a separate precision reference supply.
• ATEX Zone 2 Certification for Hazardous-Area Panels: The II 3 G ATEX certification permits installation in Zone 2 hazardous areas (occasional explosive atmosphere) when mounted inside a certified Ex e or Ex p enclosure. This qualification is mandatory for petrochemical, offshore, and grain-handling applications where alternative PSU products without ATEX approval cannot be legally installed.
• Passive Cooling Eliminates Fan-Related Maintenance: In food and beverage, pharmaceutical, and semiconductor fab environments, fan-cooled PSUs introduce particulate contamination risk and require periodic filter replacement. The 6EP1333-2BA01’s fanless design removes this maintenance interval entirely and eliminates the acoustic noise contribution from the power supply section of the panel.
• Compact 55 mm Rail Width Preserves Panel Real Estate: At 55 mm wide, the unit occupies less horizontal DIN rail space than competing 5 A PSUs from several alternative manufacturers (which commonly require 70–80 mm). In a 600 mm wide panel with a fully populated S7-1500 rack, this 15–25 mm saving can be the difference between fitting a redundant PSU on the same rail segment or requiring a second enclosure.
• Front-Panel Voltage Adjustment for Long Cable Runs: The output voltage trimmer allows field adjustment from 22.8 V to 26.4 V without opening the unit or modifying wiring. In installations where the 24 V distribution bus feeds field devices 30–50 meters from the panel, engineers can pre-compensate for the expected 0.5–1.5 V cable drop by setting the PSU output to 25.0–25.5 V, maintaining field device supply within specification without adding a booster stage.
• Parallel Operation for Redundancy and Load Sharing: Two 6EP1333-2BA01 units can be connected in parallel using the Siemens 6EP1961-2BA21 redundancy module to form a 1+1 redundant 24 V / 5 A supply. The redundancy module provides diode-based load sharing and automatic failover with no interruption to the output bus, meeting the availability requirements of SIL 2 safety-instrumented systems where PSU failure must not propagate to a process shutdown.

Quality Assurance & Global Logistics

Every Siemens 6EP1333-2BA01 unit dispatched from our Xiamen, China facility undergoes a structured pre-shipment verification protocol. Units are inspected for label authenticity, housing integrity, and terminal condition. Functional verification includes output voltage measurement at no-load and full-load, overload trip confirmation, and input voltage range validation at both 120 V AC and 230 V AC. Units that do not meet Siemens factory output specification are quarantined and not shipped.

Packaging follows export-grade standards: each unit is individually anti-static bagged, placed in foam-lined inner carton, and packed into a double-wall corrugated outer carton rated for international air freight handling. Gross weight per carton is documented on the shipping label for customs compliance. Export documentation includes commercial invoice, packing list, and certificate of origin. HS code 8504.40 is pre-declared on all shipments to minimize customs clearance delays at destination ports.

Logistics partners include DHL Express, FedEx International Priority, and UPS Worldwide Express. Standard transit times from Xiamen to major industrial hubs: Europe (Frankfurt, Rotterdam): 3–5 business days; North America (Chicago, Los Angeles): 4–6 business days; Southeast Asia (Singapore, Bangkok): 2–3 business days; Middle East (Dubai): 3–4 business days. Expedited same-day dispatch is available for orders confirmed before 14:00 CST.

All units carry a 12-month warranty against manufacturing defects from the date of shipment. Warranty claims are processed within 5 business days of receipt of the returned unit. Replacement units are dispatched via express courier at no additional freight cost to the buyer for confirmed warranty cases.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
© 2026 siemensplc.com. All rights reserved.