Schmersal SRB-NA-R-C.35/CH2A-24V Safety Relay – Obsolete SRB Series Spare Part

Technical Dossier

Product Details And Specifications

Schmersal SRB-NA-R-C.35/CH2A-24V Safety Relay – Obsolete SRB Series Spare Part

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 Schmersal SRB series was widely deployed across European and Asian manufacturing facilities throughout the 1990s and 2000s. These modules were integrated into press brakes, injection molding machines, robotic cells, and automated conveyor systems — environments where the safety architecture was engineered around specific relay logic that cannot be replicated by a modern safety PLC without a full system redesign.

When the SRB-NA-R-C.35/CH2A-24V fails, plant engineers face a binary choice: locate an original replacement unit, or initiate a capital project to re-engineer the safety circuit. The latter path requires new hardware procurement, software validation, third-party safety assessment, and extended production shutdown. For facilities operating on thin margins or managing aging asset portfolios, this is not a viable short-term option.

Condition & Reliability Assurance

Discontinued components sourced from secondary markets carry inherent risk. DriveKNMS applies a structured 5-step quality assurance process to every SRB series unit before dispatch review:

• Step 1 – Visual Inspection: Full external examination for physical damage, pin corrosion, and housing integrity.
• Step 2 – Electrolytic Capacitor Assessment: Aging electrolytic capacitors are a primary failure mode in legacy relay modules. Each unit is evaluated for capacitor condition and swelling.
• Step 3 – Contact Resistance Measurement: Relay contact resistance is measured to confirm switching performance within specification.
• Step 4 – Firmware & Configuration Verification: Where applicable, firmware version and DIP switch configuration are documented and confirmed against known SRB-NA-R-C.35/CH2A-24V factory settings.
• Step 5 – Pin and Terminal Inspection: All input/output terminals are inspected for oxidation, deformation, and continuity.

Units that do not pass all five stages are not offered for sale. Condition grade (New / Refurbished-Grade-A) is disclosed on every order confirmation.

Key Features for System Maintenance

• Drop-in replacement: The SRB-NA-R-C.35/CH2A-24V installs directly into existing SRB base sockets without modification to wiring or panel layout.
• No reprogramming required: Safety relay logic is hardware-defined. Replacing this module does not require PLC reprogramming, safety software re-validation, or changes to the machine's safety category rating.
• Avoids engineering reconstruction costs: A verified original replacement eliminates the need for a safety engineer to redesign the circuit, saving weeks of project time and tens of thousands in consulting fees.
• Preserves existing safety certification: Substituting an original-spec module maintains the machine's existing safety category compliance. Introducing a non-equivalent replacement may invalidate the machine's CE marking or ISO 13849 performance level assessment.

Q: How do I confirm the unit is genuine and not counterfeit?
A: All Schmersal units supplied by DriveKNMS are sourced from traceable industrial channels. Each unit ships with documentation of its source condition and QA inspection record. We do not source from unverified brokers.

Q: Can this module be used as a direct replacement without a safety re-assessment?
A: Replacing a failed module with an identical original-specification unit is generally considered a like-for-like maintenance action and does not trigger a mandatory safety re-assessment under most regulatory frameworks. However, your facility's safety officer should confirm this against your local machinery directive requirements.