Siemens 6ES7307-1BA00-0AA0 Retrofit Power Supply Module

Siemens 6ES7307-1BA00-0AA0 Retrofit Power Supply Module: Legacy-Compatible Upgrade for S7-300 Systems

The Siemens 6ES7307-1BA00-0AA0 is a 24 VDC / 2 A regulated power supply module from the SIMATIC S7-300 PS307 series, designed to deliver stable, filtered DC power directly to the S7-300 backplane rail. As aging S7-300 installations approach end-of-life and OEM support windows close, the 6ES7307-1BA00-0AA0 has become one of the most sought-after retrofit and replacement components for engineers tasked with extending the operational life of legacy control systems in process manufacturing, utilities, and discrete automation environments.

NINERMAS maintains verified in-stock inventory of the 6ES7307-1BA00-0AA0 with a 12-month warranty on every unit shipped. Each module undergoes pre-shipment functional testing to confirm output voltage stability, inrush current behavior, and backplane connector integrity before dispatch.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

When planning a retrofit around the 6ES7307-1BA00-0AA0, the power supply module is rarely the only component under review. In a typical S7-300 control cabinet, the PS307 sits at Slot 1 of the UR1 or UR2 rack, feeding power to the CPU module — commonly a CPU 314, CPU 315-2 DP, or CPU 317-2 PN/DP — and to all downstream I/O modules installed in the same rack. Engineers must calculate the total current draw of every installed module: digital input modules such as the SM 321 (6ES7321-1BH02-0AA0), digital output modules such as the SM 322 (6ES7322-1BH01-0AA0), and analog I/O modules such as the SM 331 or SM 332 all contribute to the backplane load. If the aggregate load approaches or exceeds 2 A, an upgrade to the 6ES7307-1EA00-0AA0 (5 A variant) should be evaluated before committing to the 1BA00 replacement.

For systems that include a CP 342-5 PROFIBUS communication processor or a CP 343-1 Ethernet module, the additional current draw of these communication modules must be factored into the power budget. Similarly, if the rack includes an IM 360 or IM 361 interface module for multi-rack expansion, the power distribution across racks must be re-verified after any PS307 replacement. In multi-rack configurations, the slave rack’s own PS307 unit must be independently assessed — the 6ES7307-1BA00-0AA0 is not a shared power source across racks.

Terminal wiring during a PS307 swap is straightforward but must be executed carefully. The L1 and N AC input terminals, the PE protective earth terminal, and the 24 VDC / M output terminals must be re-landed with correct torque (typically 0.8–1.2 Nm) and verified for polarity before energizing. If the existing cabinet uses a signal isolator or a 24 VDC distribution block downstream of the PS307, those components should be inspected for contact wear and replaced if necessary to avoid introducing noise into the newly installed supply. A programming cable — such as the PC Adapter USB (6ES7972-0CB20-0XA0) — connected to the CPU’s MPI port allows immediate online diagnostics after power-up without requiring a full program download.

Where the legacy system includes an OP 7 or OP 17 HMI panel communicating over MPI, the HMI screen configuration and tag assignments remain unaffected by a PS307 replacement, since the power supply module carries no process data. However, if the retrofit is part of a broader migration from S7-300 to S7-1500 or a SIMATIC ET 200SP distributed I/O architecture, the HMI project will require re-engineering in TIA Portal to align with the new CPU’s data block structure and communication interface.

Downtime Control During System Migration

Replacing the 6ES7307-1BA00-0AA0 in a live production environment requires careful pre-planning to minimize unplanned downtime. The recommended approach is to schedule the swap during a planned maintenance window and to prepare a full CPU memory backup — using a SIMATIC Memory Card or an online upload via STEP 7 — before de-energizing the rack. This ensures that the user program, data blocks, and hardware configuration can be restored immediately if any issue arises during the power supply exchange.

Before removing the existing PS307, document the current terminal wiring with photographs and confirm that all field devices connected to the 24 VDC rail are safely de-energized or isolated. The physical swap of the 6ES7307-1BA00-0AA0 itself takes under five minutes once the rack is de-powered: release the bus connector, unscrew the module retaining screw, disconnect the AC input and DC output terminals, and reverse the process with the replacement unit. After re-energizing, the CPU should return to RUN mode automatically if the mode selector is in the RUN position and the program is intact in retentive memory.

For systems where continuous control is critical — such as those managing compressor control loops, boiler management sequences, or conveyor interlocks — a hot-standby strategy using a redundant 24 VDC supply in parallel (with diode decoupling) can eliminate downtime entirely during the PS307 replacement. NINERMAS can advise on compatible parallel supply configurations upon request. All replacement units are shipped with pre-shipment test documentation, reducing on-site commissioning time and supporting rapid return-to-service after installation.

Retrofit Support FAQ

Q1: Is the 6ES7307-1BA00-0AA0 a direct drop-in replacement for the 6ES7307-1BA01-0AA0 and 6ES7307-1BA80-0AA0?
In most cases, yes. The 1BA00, 1BA01, and 1BA80 hardware revisions share the same electrical ratings (24 VDC / 2 A output, 120/230 VAC input) and the same physical form factor. However, always verify the hardware revision label on the existing unit and cross-reference with the S7-300 system manual to confirm compatibility with your specific CPU and rack combination before installation.

Q2: Does the replacement unit require any software configuration in STEP 7 or TIA Portal?
No. The PS307 power supply module is a passive hardware component and does not appear as a configurable object in the STEP 7 hardware configuration or TIA Portal device tree. After physical installation, the CPU will recognize the restored power rail and resume normal operation without any software changes. A diagnostic buffer check via STEP 7 online mode is recommended to confirm no fault entries were generated during the swap.

Q3: What pre-shipment testing is performed on each 6ES7307-1BA00-0AA0 unit?
Every unit supplied by NINERMAS is tested for output voltage accuracy (24 VDC ±1%), output current capacity at rated load (2 A continuous), input voltage switching (120 V and 230 V modes), and backplane connector mechanical integrity. A test report is available upon request. All units are covered by a 12-month warranty from the date of shipment.

Q4: What is the typical lead time and stock availability?
NINERMAS maintains ready stock of the 6ES7307-1BA00-0AA0 to support urgent maintenance and planned retrofit projects. Standard orders are dispatched within 1–3 business days. For large-quantity procurement or long-term spare parts programs covering multiple S7-300 racks, please contact our sales team to discuss volume pricing and reserved stock arrangements.