Siemens 6EP1334-1LB00 Replacement for SITOP PSU100L

Product Overview

Siemens 6EP1334-1LB00 Replacement for SITOP PSU100L: Smooth Transition from Legacy Power Infrastructure

The Siemens 6EP1334-1LB00 is a high-reliability DIN rail-mounted stabilized power supply from the SITOP PSU100L series, delivering a regulated 24 VDC output at 10 A from a wide-range AC input (120–230 VAC, 50/60 Hz). Designed for demanding industrial environments, this unit is a direct replacement or upgrade solution for aging or discontinued SITOP power supply modules deployed across Siemens S7-300, S7-400, ET 200 distributed I/O stations, PROFIBUS-DP networks, and legacy control cabinet installations.

For facilities running older Siemens automation infrastructure — including first-generation SITOP SMART, SITOP modular, or third-party 24 VDC rail supplies — the 6EP1334-1LB00 offers a mechanically and electrically compatible upgrade path. Its compact 70 mm DIN rail footprint, standard terminal block wiring, and universal AC input make it a practical drop-in replacement in most existing control cabinet layouts without requiring panel redesign or rewiring of field devices.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful migration from an aging 24 VDC power infrastructure to the 6EP1334-1LB00 typically involves coordinating several interdependent components within the same control cabinet or automation system. When replacing a failed or end-of-life power supply in a Siemens S7-300 rack, engineers often simultaneously audit the CPU 315-2 DP (6ES7315-2AH14-0AB0) or CPU 314C-2 DP for firmware currency, since power supply replacement is a natural maintenance window for broader system health checks.

In distributed I/O architectures using ET 200S or ET 200M stations connected via PROFIBUS-DP, the 6EP1334-1LB00 supplies stable 24 VDC bus power to interface modules such as the IM 151-1 (6ES7151-1AA06-0AB0) and associated digital input/output modules. Ensuring the replacement PSU meets the aggregate current draw of all installed I/O modules — including SM 321 digital input modules and SM 322 digital output modules — is a critical pre-installation step.

For systems incorporating PROFIBUS-DP communication processors such as the CP 342-5 (6GK7342-5DA02-0XE0), the 6EP1334-1LB00 provides the clean, regulated 24 VDC supply required to maintain deterministic bus cycle times. Voltage ripple and transient response specifications of the PSU100L series are engineered to prevent communication timeouts on PROFIBUS segments running at 1.5 Mbit/s or 12 Mbit/s.

Control cabinets undergoing partial modernization — for example, retaining an existing Siemens OP 277 HMI panel or TP 177B touch panel while replacing the power supply — benefit from the PSU100L’s stable output, which eliminates HMI brownout events caused by aging capacitors in legacy supplies. Similarly, SITOP UPS1600 (6EP4134-3AB00-0AY0) DC-UPS modules can be paired directly with the 6EP1334-1LB00 to provide buffered power during mains interruptions, protecting CPU memory and open communication sessions.

In retrofit projects involving Siemens MICROMASTER 440 or SINAMICS G120 variable frequency drives, the 24 VDC control circuit supply — often sourced from a dedicated DIN rail PSU — is a common failure point. Replacing the aging supply with the 6EP1334-1LB00 restores stable control voltage to the drive’s CU240E-2 control unit and associated BOP-2 operator panel, without requiring changes to the drive parameterization or motor wiring.

For legacy installations using Siemens S5-115U or S5-135U PLCs being migrated to S7-300 architecture, the 6EP1334-1LB00 serves as the standardized 24 VDC supply for the new rack, replacing proprietary S5-era power modules. The migration typically also involves installing a STEP 7 to TIA Portal project conversion and updating field wiring from S5 I/O terminal assignments to S7 SM module pinouts — all of which can proceed without interrupting the PSU installation.

Retrofit Guidance FAQ

Q: Can I wire the 6EP1334-1LB00 directly to my existing terminal block without rewiring field devices?
A: Yes. The PSU100L uses standard screw terminals at the same pitch as most legacy 24 VDC DIN rail supplies. Output polarity (L+/M) and PE connections follow IEC 60364 conventions. No field device rewiring is required if the existing supply was also 24 VDC / 10 A.

Q: Is the 6EP1334-1LB00 compatible with PROFIBUS-DP and PROFINET systems?
A: Yes. As a standalone 24 VDC supply, it provides bus power to any PROFIBUS-DP or PROFINET device requiring 24 VDC auxiliary supply, including IM modules, CP modules, and I/O stations. It does not participate in the communication protocol itself.

Q: Will this PSU fit in the same DIN rail slot as my current supply?
A: The 6EP1334-1LB00 occupies approximately 70 mm of DIN rail width. Verify your cabinet’s available rail space. In most S7-300 and ET 200 cabinet layouts, this is a direct mechanical fit. If the legacy supply was wider, a blank cover plate may be used to fill the gap.

Q: Do I need to modify my PLC program after replacing the power supply?
A: No. The 6EP1334-1LB00 is a passive power component. It does not appear in the hardware configuration (HW Config) in STEP 7 or TIA Portal, and replacing it requires no program changes, OB modifications, or hardware reconfiguration downloads.

Q: What happens to my CPU memory during the PSU swap?
A: A cold power cycle will occur. Ensure your CPU has a valid memory card (MMC or SD card) with the current project loaded. If using a SITOP UPS module, it can buffer the 24 VDC supply during the swap to maintain CPU state. Otherwise, plan for a controlled shutdown and restart sequence.

Q: Can this unit replace third-party 24 VDC / 10 A DIN rail supplies from other manufacturers?
A: Yes, provided the third-party supply used standard 35 mm DIN rail mounting, screw terminals, and 24 VDC / 10 A output. The 6EP1334-1LB00’s wide-range AC input (120–230 VAC) also accommodates installations in regions with different mains voltages.

Warranty Assurance

Every Siemens 6EP1334-1LB00 shipped by TOPNLMS is covered by a 12-month warranty from the date of delivery. Prior to shipment, each unit undergoes functional output voltage verification, load regulation testing, and visual inspection for physical integrity. Units are packed in anti-static, shock-resistant packaging suitable for international air and sea freight.

In the event of a warranty claim, TOPNLMS provides a replacement dispatch within 3–5 business days upon confirmation of the defect. Our technical support team is available to assist with installation verification, compatibility questions, and commissioning guidance. We maintain stock of the 6EP1334-1LB00 and related SITOP series components to support urgent replacement requirements with minimal lead time.

For volume procurement, OEM integration projects, or MRO (Maintenance, Repair & Operations) contracts requiring scheduled delivery, please contact our sales team directly to discuss pricing, lead times, and documentation requirements including test reports and certificates of conformity.