Siemens 3RT2026-1AG20 Power Contactor – Obsolete SIRIUS Spare Part

Technical Dossier

Product Details And Specifications

Siemens 3RT2026-1AG20 Power Contactor – Obsolete SIRIUS Spare Part

When a Siemens 3RT2026-1AG20 contactor fails in a legacy motor control center, the immediate question is not where to find a replacement — it is whether the entire control panel must be redesigned. For facilities running SIRIUS-based motor starters integrated into older Siemens S7-300 or S5-series automation architectures, a single failed contactor can cascade into a production stoppage that forces a capital expenditure decision: source the original part, or fund a full panel re-engineering project that routinely exceeds six figures. DriveKNMS maintains RFQ-reviewed sourcing status of the 3RT2026-1AG20 specifically to eliminate that forced choice. This is not a generic substitute. It is the original Siemens SIRIUS contactor, sourced and held for exactly this scenario.

RFQ support for obsolete parts: Send the model number, required quantity and destination so DriveKNMS can confirm sourcing options before quotation.

Technical Specifications

Solving the Discontinued Hardware Crisis

The 3RT2026-1AG20 was a standard building block in Siemens SIRIUS motor starter assemblies deployed across manufacturing, water treatment, and process industries throughout the 1990s and 2000s. These assemblies were frequently integrated with Siemens S7-300 PLCs, older ET 200 distributed I/O stations, and in some installations, legacy S5-series controllers. The contactor's 110 V AC coil voltage is a specification that does not map cleanly onto current-generation SIRIUS 3RT2 variants without auxiliary transformer modifications — a change that requires panel re-certification in most jurisdictions.

For plant engineering teams, the arithmetic is straightforward. A single motor control center panel containing 12 to 20 of these contactors represents an asset that, if forced into full replacement, carries a re-engineering, procurement, installation, and re-commissioning cost that typically ranges from USD 80,000 to USD 300,000 depending on panel complexity and local labor rates. Sourcing original 3RT2026-1AG20 units at current spare part pricing extends that asset's operational life by 5 to 10 years at a fraction of that cost.

Condition & Reliability Assurance

Every 3RT2026-1AG20 unit processed through DriveKNMS undergoes a structured 5-step inspection protocol before it is offered for sale:

• Step 1 – Electrolytic Capacitor Assessment: Any auxiliary electronics are inspected for capacitor aging, swelling, or electrolyte leakage — a primary failure mode in parts that have been in storage or light service for extended periods.
• Step 2 – Coil Resistance Verification: Coil resistance is measured and compared against published Siemens specifications to confirm the 110 V AC coil is within tolerance and will operate reliably at rated voltage.
• Step 3 – Contact Condition Inspection: Main power contacts and auxiliary contacts are inspected for erosion, pitting, and contact gap integrity. Units with contact wear beyond acceptable limits are rejected.
• Step 4 – Pin and Terminal Corrosion Check: All screw terminals and connection points are inspected for oxidation and corrosion. Terminal threads are verified for full engagement capability.
• Step 5 – Mechanical Operation Test: The contactor is actuated manually and electrically to confirm full armature travel, positive contact closure, and spring return function.

Units that do not pass all five steps are not offered for sale. Condition grade (new surplus, tested serviceable, or refurbished) is disclosed at the time of quotation.

Key Features for System Maintenance

How do I know the unit is genuine Siemens and not a counterfeit?
All units are inspected for Siemens markings, date codes, and construction consistency. We do not source from unverified secondary markets. Provenance documentation is available on request for critical applications.

Should I buy more than one unit?
For any system with more than three of these contactors installed, maintaining a minimum of two spare units is a standard risk management practice. The cost of a second spare is negligible relative to the cost of an unplanned production stoppage while a replacement is sourced. For systems where this contactor is in continuous heavy-duty cycling service, a higher buffer is warranted.