Siemens ep1434-2ba20

By Abdullah Zahid
13 min read
Siemens 6EP1434-2BA20 SITOP PSU300S 24V 10A DIN rail power supply for industrial control cabinet automation

Siemens 6EP1434-2BA20 SITOP PSU300S 24 V/10 A Stabilized Power Supply — Specifications, Alternatives, and Buying Guide

When a controls engineer is specifying or replacing the primary 24V DC power source in a 3-phase industrial cabinet, the decision usually comes down fast: does this unit handle the load, fit the rail space, and ship in time? The Siemens 6EP1434-2BA20 — officially the SITOP PSU300S 24 V/10 A stabilized power supply — converts 3-phase AC input (340–550V wide range) into regulated 24V DC at 10A continuous, delivering 240W in a compact 70 x 125 x 120 mm DIN rail package. With an MTBF of 500,000 hours at 40°C and field data showing 1,458,540 hours, this is one of the most specified switched-mode DIN rail power supplies in industrial automation worldwide.

If you have already confirmed this is the right part, check current pricing and availability at LeadTime.ca — ships worldwide.

Who Should Buy the 6EP1434-2BA20 — and Who Shouldn't

This model is the right choice for engineers and procurement professionals sourcing a 24V DC DIN rail power supply for a 3-phase industrial cabinet application. It is specifically appropriate when all of the following criteria are met:

  • Your cabinet receives 3-phase AC supply at 400–500V nominal (or anywhere in the wide-range 340–550V band)
  • Total continuous 24V DC load current does not exceed 10A (up to 12A is available at ambient temperatures up to 45°C)
  • DIN rail space permits a 70 mm wide, 125 mm high, 120 mm deep module on a standard EN 60715 35 mm rail
  • Your application requires integrated short-circuit proof output and overvoltage protection without a separate output fuse or relay
  • Safety certifications including cULus, CSA C22.2, and CB-Certificate are required for the project
  • An external 3-16A miniature circuit breaker on the AC input side is acceptable and can be installed by your electrical contractor

If your load exceeds 10A, your cabinet has only single-phase AC supply, or you need integrated redundancy or buffer hold-up, this is not the correct model. See the variant comparison table below — the SITOP PSU300S 24V/20A (6EP1434-2BA40) or a buffer module combination may be the right fit instead.

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What the 6EP1434-2BA20 Does in a Real Industrial System

The Siemens 6EP1434-2BA20 is a switched-mode stabilized power supply that takes 3-phase AC from a facility distribution panel — typically 400V at 50 Hz or 480V at 60 Hz, anywhere in the 340–550V wide-range band — and converts it to clean, regulated 24V DC for the control circuit. It is not a UPS, not a battery charger, and not a variable-voltage source. Its job is to sit permanently in the cabinet and deliver steady 24V DC to every downstream control device simultaneously: PLC CPU and I/O modules, solenoid valves, proximity sensors, indicator lamps, safety relays, and emergency stop chains.

At 240W output capacity, the 6EP1434-2BA20 is sized for mid-density control cabinets — a SIMATIC S7-1200 or S7-1500 rack with 15–20 I/O modules plus a handful of solenoid valves and field devices is well within its capability. Voltage regulation is tight: 0.1% on slow input fluctuations and 1% on fast ±15% input changes. The output potentiometer allows field adjustment between 24V and 28V if a higher rail voltage is needed for long cable runs or specific device requirements. The green LED status indicator and normally-open relay contact (rated 60V DC / 0.3A) provide a hardware-level power-good signal that can feed a PLC digital input or monitoring relay without any additional components.

Unlike simpler transformer-rectifier designs, the switched-mode topology means efficiency reaches 91% — important in cabinets where thermal management is a constraint. The unit is short-circuit proof by design, operating in constant-current mode at 13A typical (16A max RMS) during a fault, and recovering automatically once the fault clears. No manual reset fuse on the output side is required.

Typical System Architecture: Where This PSU Sits in the Signal Chain

The 6EP1434-2BA20 sits between the facility's 3-phase AC distribution and every 24V DC control device in the cabinet — it is the sole power conversion stage in a standard DIN rail automation rack.

  • Facility 3-phase AC panel (400–500V) feeds a 3-pole miniature circuit breaker (3–16A, characteristic C) mounted upstream of the PSU on the same DIN rail or in an adjacent compartment
  • The 6EP1434-2BA20 receives switched 3-phase AC through its L1, L2, L3 input terminals and outputs regulated 24V DC on its screw output terminals
  • The 24V DC output connects to a main distribution terminal block, from which individual branch circuits feed the PLC rack, safety relay modules, solenoid valve manifolds, and field sensors
  • The relay contact output (terminals 13–14) connects to a PLC digital input or panel monitoring relay to signal power-good status
  • Optional: A SITOP buffer module (6EP4134 series) can be inserted between the PSU output and the distribution block to provide hold-up time during brief AC line interruptions

Typical Applications and Deployment Scenarios

In automotive assembly, the 6EP1434-2BA20 powers the 24V backbone of press cell control cabinets — feeding safety zone scanners, safety relays, control pushbuttons, and emergency stop chains while the main machine drive runs on a separate power path. The compact footprint is especially valued in retrofit projects where existing cabinet real estate is limited and a failed legacy PSU needs a same-footprint replacement without major rewiring.

Food and beverage packaging lines use this model extensively to power filling machine and palletizer control circuits. The wide input range (340–550V) handles voltage variations common in large production facilities with fluctuating supply quality, and the 91% efficiency keeps cabinet temperatures manageable in environments where cooling is difficult.

In plastics injection molding and extrusion, the 6EP1434-2BA20 is frequently specified as the 24V source for a SIMATIC S7-1500 PLC with multiple distributed I/O racks, solenoid valve islands, and machine safety systems. The integrated short-circuit protection prevents a wiring fault on a single output branch from collapsing the entire 24V rail.

Mobile and off-road machine builders running a 3-phase onboard generator at 400V, 50 Hz also use this model — the operating temperature range of -25°C to +70°C and the wide input voltage tolerance accommodate the less-stable power quality typical of generator-fed systems in construction or agricultural equipment.

Application Typical Deployment
Automotive press cell control 24V power for safety relays, zone scanners, and E-stop chain in a 3-phase 400V facility
Food & beverage filling/palletizing line Primary 24V DC source for PLC I/O, solenoid valves, and conveyor controls in a stainless panel
Plastics injection molding cabinet SIMATIC S7-1500 rack plus distributed I/O and valve islands; single PSU at 10A continuous
Cabinet retrofit / PSU replacement Drop-in replacement for failed legacy DIN rail PSU; same 70 mm rail width, no rewiring required
Mobile machine with onboard generator 3-phase 400V generator feeds 6EP1434-2BA20; -25°C to +70°C range handles outdoor environments
Centralized automation rack 24V backbone for 8–12 modular control modules in a distributed manufacturing cell

Purchase-Decision Specifications at a Glance

Parameter Value
Input Voltage (Nominal / Wide Range) 400–500V AC 3-phase / 340–550V wide range
Input Frequency 47–63 Hz
Output Voltage 24V DC (adjustable 24–28V via potentiometer)
Output Current (Rated / Derated) 10A continuous / 12A up to +45°C; derates above +60°C at 5% per Kelvin
Output Power 240W
Short-Circuit Protection Constant current 13A typical, 16A max RMS; auto-recovery
Efficiency 91%
MTBF (at 40°C / Field Data) 500,000 hours / 1,458,540 hours field data
Dimensions (W x H x D) 70 x 125 x 120 mm
Operating Temperature -25°C to +70°C

Full technical specifications are available on the product page at LeadTime.ca.

SITOP PSU300S Variant Comparison: Which Current Rating Do You Actually Need?

Model Output Current Output Power Best Fit
6EP1434-1BA20 5A 120W Small control circuits; PLC only with basic relays; total load under 5A
6EP1434-2BA20 (this model) 10A (12A to +45°C) 240W Mid-density cabinets; S7-1200/S7-1500 with I/O modules, solenoids, sensors
6EP1434-2BA40 20A 480W High-density cabinets; load exceeds 10A; future expansion planned
SITOP PSU300S 24V/30A (larger variant) 30A 720W Large centralized rack; multiple sub-panels; highest current 3-phase option in family

If your 24V circuit load is comfortably below 10A continuous and your cabinet has 3-phase AC supply, the 6EP1434-2BA20 is the correct choice — check current availability and pricing at LeadTime.ca.

Expert Verdict: Reliability Record, Real Limits, and Procurement Reality

The 6EP1434-2BA20 earns its place as a default specification in Siemens-centric automation projects for a concrete reason: the combination of 500,000-hour MTBF at 40°C, integrated short-circuit proof output, and a field data figure of 1,458,540 hours means it rarely fails in service. For a controls engineer specifying a machine that will run for ten or more years, that track record eliminates a class of risk that lower-cost alternatives cannot match on paper. The 91% efficiency and wide input range (340–550V) also mean it handles real-world supply quality without nuisance trips in facilities with generator backup or variable grid voltage.

The honest limits are straightforward. This is a single-channel, non-redundant supply — if the 6EP1434-2BA20 fails, the 24V rail goes down until replacement. For applications requiring uninterrupted operation through brief AC outages or PSU failure, a buffer module (SITOP 6EP4134 series) or a dual-PSU topology with a selectivity module (6EP4137-2FF01) is required and cannot be avoided. The 10A output ceiling is also a hard constraint; if a machine design grows to include additional safety scanners, extra I/O modules, or a second solenoid valve island, the 6EP1434-2BA40 at 20A is the right next step — not a workaround on this model. Finally, the mandatory external 3-16A miniature circuit breaker on the AC input side is a real project cost that sometimes catches procurement off-guard; it is not included and must be specified and installed separately.

From a sourcing perspective, the 6EP1434-2BA20 is an active product with a delivery release from 2016 and a last-modified date of April 2025, confirming it is not being phased out. Typical market pricing falls in the $300–$500 USD range for single units, with volume discounts available at 5–10 units and negotiated pricing at 20 or more. Lead times at distributors reporting temporary stock constraints run 4–8 weeks for new orders; integrators managing downtime risk typically carry 1–2 spare units. If you are ordering for a build or confirming stock before committing to a delivery schedule, view current stock and pricing at LeadTime.ca.

For volume pricing or to confirm lead time before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

Wiring and Installation Overview

  • Install an external 3-pole miniature circuit breaker rated 3–16A (characteristic C) on the 3-phase AC input upstream of the PSU — this is mandatory and not included; the switch-on inrush current reaches 20A maximum, so the breaker must tolerate this transient without nuisance tripping
  • Connect L1, L2, L3 phase conductors to the AC input terminals following IEC 60757 color conventions (brown, black, grey); connect PE ground per local electrical codes
  • Wire the 24V DC output using 2.5 mm² (14 AWG) conductors for runs under 5 meters; use 4 mm² (12 AWG) for longer runs to minimize voltage drop at 10A
  • The relay contact output (terminals 13–14, rated 60V DC / 0.3A) closes when 24V output is stable — connect to a PLC digital input or monitoring relay to provide a hardware power-good signal
  • After mounting on EN 60715 35 mm DIN rail, verify a minimum 25 mm air gap above and below the unit for convection cooling; confirm the DIN latch is fully engaged before energizing

Compatible Modules and System Expansion Options

The 6EP1434-2BA20 is designed to work within the broader SITOP power supply ecosystem. The following modules extend its capability for applications requiring buffer hold-up, redundancy, or current expansion:

  • SITOP Buffer Module 6EP4134-0GB00 — Adds hold-up time to the 24V output during brief AC line interruptions; connects between the PSU output and the 24V distribution block
  • SITOP Selectivity Module 6EP4137-2FF01 — Enables dual-PSU hot-standby topology with automatic failover if the primary supply fails; required for true redundant power architecture
  • SITOP PSU300S 24V/20A (6EP1434-2BA40) — Parallel upgrade path when load growth exceeds 10A; same product family, same DIN rail class
  • Siemens 3RV2011-1DA10 or 3RV2711-1DD10 — Recommended miniature circuit breakers for AC input protection; sized for the 6EP1434-2BA20 inrush and rated current requirements

Wrong-Part Prevention Checklist Before You Order

Before placing an order for the 6EP1434-2BA20, verify every item on this checklist — each point represents a real ordering mistake that results in returns, project delays, or unsafe installations:

  1. Confirm your machine cabinet has 3-phase AC supply (not single-phase). This model is 3-phase; single-phase requires different SKU.
  2. Verify total 24V DC circuit current does not exceed 10A continuous (12A at higher temps; 150% overload 5s/min max). Sum all loads.
  3. Check space: DIN rail width must be minimum 70mm; height 225mm for standard mounting. Measure cabinet interior.
  4. Confirm external protection: Your electrical contractor must install a 3-16A miniature circuit breaker on the AC input (not included).
  5. Verify output voltage range acceptable: This unit adjusts 24-28V via potentiometer. If exact 24V ±0.5V required, verify trim pot range acceptable.
  6. Check site environmental: Operating range -25 to +70°C and humidity 5-95% (no condensation). Verify your facility climate control.
  7. Ensure galvanic isolation needed: This unit provides safety extra-low voltage (SELV) per EN 60950-1. Verify safety circuit design requires this.

If any item on this checklist raises a question about fit, contact the LeadTime.ca team before ordering — we can help confirm the correct SKU or identify the right alternative within the SITOP family.

Frequently Asked Questions

Does the 6EP1434-2BA20 require an external fuse or circuit breaker, and what size?

Yes — an external 3-pole miniature circuit breaker rated between 3A and 16A (characteristic C) is mandatory on the 3-phase AC input side. The unit has no built-in input fuse. The switch-on inrush current reaches 20A maximum (I²t 0.5 A²·s), so the breaker must be selected to tolerate this transient. Siemens 3RV2011-1DA10 or 3RV2711-1DD10 are commonly specified with this model for straightforward integration.

Can the 6EP1434-2BA20 be used in a redundant or backup power configuration?

Not on its own. The 6EP1434-2BA20 is a single-output, non-redundant supply. To achieve redundancy, a dual-PSU topology using two units plus the SITOP Selectivity Module 6EP4137-2FF01 is required for automatic hot-standby failover. For hold-up time during brief AC outages, the SITOP Buffer Module 6EP4134-0GB00 connects to the output. Neither module is integrated into this unit.

What happens if the 24V load exceeds 10A — does the unit shut down immediately?

The unit enters constant-current protection mode rather than shutting down immediately. Short-circuit current is limited to 13A typical (16A max RMS). An overload of up to 150% of rated output current (15A) is tolerated for a maximum of 5 seconds per minute. Sustained overloads beyond this threshold will cause the unit to reduce output. If your application regularly approaches or exceeds 10A, the 6EP1434-2BA40 at 20A is the correct upgrade path.

What is the correct procedure if the green LED fails to illuminate after energizing?

First, confirm the external AC circuit breaker is in the ON position and has not tripped. Measure 3-phase voltage at the PSU input terminals with a multimeter on AC setting to verify the supply is present and within the 340–550V range. If AC supply is confirmed but the LED remains dark, inspect all input screw terminal connections for loose wires. If all connections are verified and the LED is still not illuminated, the unit has an internal fault and requires replacement.

Is the 6EP1434-2BA20 approved for use in hazardous or classified locations?

No. The 6EP1434-2BA20 carries cULus, CSA C22.2, CB-Certificate, BIS, EAC, and UKCA certifications, but it does not hold ATEX, IECEx, UL HazLoc, FM, or Class 1 Division 2 approvals. It is not rated for use in hazardous classified locations. Applications in explosive atmospheres require a different product category entirely.

How does the output voltage adjustment potentiometer work, and what is the range?

The trim potentiometer is accessible on the face of the unit and adjusts the output voltage between 24V and 28V DC. Turning the pot clockwise increases the output voltage. This adjustment is useful when long cable runs create voltage drop that would otherwise reduce the rail voltage below device operating minimums. The potentiometer setting should be documented after commissioning to avoid undocumented drift if the unit is later adjusted by field personnel.

Why Order From LeadTime.ca

  • LeadTime.ca ships worldwide — whether you are sourcing from North America, Europe, Asia-Pacific, or anywhere else, orders are processed and fulfilled globally
  • Hard-to-find and temporarily out-of-stock Siemens parts can be sourced through distributor network access and regional warehouse inventory checks
  • Volume pricing is available for integrators and OEMs ordering 5 units or more — contact the team directly for a quote before committing to a build schedule
  • Fast response times for lead time confirmation — critical when a cabinet PSU failure is causing unplanned downtime and a spare is needed urgently
  • Authorized distribution with exact catalog number verification — no substitutions without buyer confirmation

At-a-Glance Summary

  • Model: Siemens 6EP1434-2BA20 — SITOP PSU300S 24 V/10 A stabilized power supply
  • Output: 24V DC at 10A continuous (240W); adjustable to 28V via onboard potentiometer
  • Input: 3-phase AC 340–550V wide range, 47–63 Hz — not compatible with single-phase supply
  • MTBF: 500,000 hours at 40°C; field data confirms 1,458,540 hours
  • Dimensions: 70 x 125 x 120 mm; mounts on EN 60715 35 mm DIN rail; weight 0.7 kg
  • Short-circuit protection: constant current 13A typical, 16A max RMS; auto-recovery, no manual reset required
  • Efficiency: 91%; operating temperature -25°C to +70°C
  • Certifications: cULus (UL 508, UL 62368-1 File E197259), CSA C22.2, CB-Certificate, BIS, EAC, UKCA — not ATEX or hazardous location rated
  • External AC protection mandatory: 3-16A miniature circuit breaker required; not included with unit
  • Typical market price: $300–$500 USD single unit; volume pricing available at 5+ units