Siemens 6EP1336-3BA00-8AA0 Retrofit Power Supply

Siemens 6EP1336-3BA00-8AA0 Retrofit Power Supply: Legacy System Compatible Upgrade

The Siemens 6EP1336-3BA00-8AA0 is a ruggedized SITOP series DC power supply module engineered for demanding industrial environments. As aging automation infrastructure reaches end-of-life, this unit serves as a proven retrofit-compatible replacement for obsolete or discontinued power supply modules across SIMATIC S7-300, S7-400, and equivalent legacy control platforms. NINERMAS maintains verified stock of the 6EP1336-3BA00-8AA0 with full pre-shipment functional testing and a 12-month warranty, enabling maintenance teams to execute controlled replacements without extended procurement lead times.

The 6EP1336-3BA00-8AA0 delivers a regulated 24 V DC output with wide-range AC input tolerance, making it directly compatible with existing terminal wiring in most legacy control cabinets. Its compact DIN-rail mounting footprint matches the mechanical envelope of earlier SITOP PSU100S and PSU200M variants, reducing the need for panel modifications during retrofit. Engineers replacing end-of-life units such as the 6EP1333-3BA00 or 6EP1334-3BA00 will find the 6EP1336-3BA00-8AA0 a functionally equivalent successor with enhanced thermal tolerance suited to harsh-environment installations.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

Replacing a power supply module in a live control cabinet requires systematic planning to protect both personnel and the integrity of the running process. When the 6EP1336-3BA00-8AA0 is selected as the replacement unit, the first step is to audit the total DC load connected to the existing supply. This includes all SIMATIC S7-300 CPU modules, SM 321/SM 322 digital I/O modules, SM 331/SM 334 analog I/O modules, CP 343-1 PROFINET communication processors, and any 24 V DC field devices powered from the same bus. Summing the nameplate current draw of each connected module against the output current rating of the 6EP1336-3BA00-8AA0 confirms whether the replacement unit is correctly sized or whether a supplementary SITOP PSU100S buffer module is required to handle transient inrush during CPU restart cycles.

Terminal wiring is the next critical checkpoint. The 6EP1336-3BA00-8AA0 uses screw-type terminals with the same pitch and labeling convention as earlier SITOP variants, so existing wire ferrules and cable markers can typically be reused without modification. Engineers should photograph the existing terminal layout before disconnection and verify that the L+, M, and PE assignments match the replacement unit’s terminal diagram. Where the original installation used a 6EP1332-1SH31 or similar single-phase input variant, the wide-range input of the 6EP1336-3BA00-8AA0 accommodates both 120 V and 230 V AC supplies without jumper changes, simplifying cross-site standardization.

Backplane and rack considerations are equally important. In S7-300 configurations, the power supply slots on a UR1 or UR2 universal rack must be verified for mechanical compatibility. The 6EP1336-3BA00-8AA0 does not occupy a backplane slot in the traditional sense — it feeds the DC bus rail — but its physical width must be confirmed against available panel space, particularly in compact cabinets where ET 200M distributed I/O stations or IM 153-2 interface modules are mounted in close proximity. Where space is constrained, the absence of a fan in the 6EP1336-3BA00-8AA0’s convection-cooled design is an advantage, eliminating a common failure point and reducing maintenance intervals.

For systems incorporating a SIMATIC HMI panel such as a TP700 Comfort or MP277, the 24 V DC supply to the HMI must be traced and confirmed as either shared with or independent from the PLC supply bus. If shared, the replacement power supply must be sized to cover the combined load. HMI screen configurations and tag connections do not require modification during a power supply swap, but the HMI should be powered down before the supply is disconnected to prevent file system corruption on the panel’s internal storage. After the 6EP1336-3BA00-8AA0 is installed and energized, the HMI should be restarted and all process screens verified for correct tag communication before the system is returned to automatic mode.

Signal isolators and intrinsic safety barriers installed in the same cabinet — such as those used with 4–20 mA analog loops feeding SM 331 analog input modules — should be checked for supply voltage sensitivity. Most DIN-rail signal conditioners accept 24 V DC ±15%, which is well within the regulation tolerance of the 6EP1336-3BA00-8AA0. Where PROFIBUS DP segments are present, the RS-485 repeater or OLM optical link module powering the segment should be confirmed as separately fused to isolate any fault on the field bus from the main PLC supply. Programming cables such as the PC Adapter USB A2 or MPI/DP adapter used for S7-300 online diagnostics should be disconnected before the supply is replaced to avoid communication errors during the changeover.

Downtime Control During System Migration

Minimizing unplanned downtime during a power supply replacement begins with pre-staging the 6EP1336-3BA00-8AA0 and verifying its output voltage on the bench before the maintenance window opens. NINERMAS ships each unit with a pre-shipment functional test report confirming output voltage, ripple, and overload response, which allows the site engineer to proceed directly to installation without incoming inspection delays.

A structured changeover sequence protects the existing PLC program and field device states. The recommended approach is to place the S7-300 CPU in STOP mode via the SIMATIC Manager or TIA Portal online connection, record the current process values and alarm states from the HMI historian, and then de-energize the cabinet in a controlled sequence — field devices first, then the PLC rack, then the power supply input. This sequence prevents voltage transients from propagating through the DC bus during disconnection. After the 6EP1336-3BA00-8AA0 is installed and the input supply restored, the output voltage should be measured at the DC bus terminals before the PLC rack is re-energized, confirming correct polarity and voltage level.

Once the PLC is powered and the CPU transitions to RUN mode, the program logic resumes from the last saved state in retentive memory. No program download is required for a like-for-like power supply replacement. The site engineer should monitor the CPU diagnostic buffer in SIMATIC Manager for any startup faults, verify that all I/O modules report green status LEDs, and confirm that the PROFINET or PROFIBUS communication links to remote I/O stations and drives have re-established before releasing the system to production. Total controlled changeover time for an experienced engineer is typically 30–60 minutes, making the 6EP1336-3BA00-8AA0 replacement feasible within a standard planned maintenance window.

Retrofit Support FAQ

Q1: Is the 6EP1336-3BA00-8AA0 a direct replacement for the 6EP1334-3BA00?
Yes. The 6EP1336-3BA00-8AA0 is functionally and mechanically compatible with the 6EP1334-3BA00 and other same-series SITOP predecessors. Verify the output current rating against your total DC load before installation. Terminal wiring and DIN-rail mounting are identical.

Q2: What commissioning checks are required after installation?
Measure DC output voltage at the bus terminals under no-load and full-load conditions. Confirm upstream MCB rating is appropriate for the input current draw. Verify earthing continuity from the PE terminal to the cabinet earth bar. Check all connected I/O modules and communication processors for correct status indication before returning the CPU to RUN mode.

Q3: Does NINERMAS provide pre-shipment testing and warranty coverage?
Yes. Every 6EP1336-3BA00-8AA0 unit shipped by NINERMAS undergoes functional output testing prior to dispatch. A 12-month warranty is provided from the shipment date, covering manufacturing defects and functional failures under normal operating conditions. Expedited shipping options are available for urgent maintenance requirements.

Q4: What is the typical lead time and stock availability?
NINERMAS maintains in-stock inventory of the 6EP1336-3BA00-8AA0 to support urgent spare parts requirements. Standard orders are processed and dispatched within 1–3 business days. For large-quantity or long-term spare parts program requirements, contact our sales team to discuss reserved stock arrangements and scheduled delivery programs.