ABB  07KT97H3 – Industrial Control Relay Module for Process Automation

The ABB  07KT97H3 is a compact relay module designed primarily for signal isolation and switching in industrial automation systems. It’s commonly used in applications where discrete signals need to be reliably transferred between control systems and field devices—especially in environments prone to electrical noise or ground loop issues. From my experience, this module shows up most often in retrofit projects involving older S7-300 PLC setups, where compatibility with existing I/O racks matters.

Key Features

• Signal Isolation: Provides galvanic isolation between input and output circuits, which helps prevent interference from affecting sensitive controllers.
• Modular Design: Fits standard ABB  S7-300 rail mounting systems, making integration straightforward if you’re already using that ecosystem.
• Relay Outputs: Equipped with mechanical relay contacts capable of switching both AC and DC loads—useful when interfacing with legacy equipment that doesn’t play well with solid-state outputs.
• DIN-Rail Mountable: One thing I appreciate is how easily it installs alongside other modules without requiring custom brackets or additional space.
• Status Indication: LED indicators for operation status help during commissioning and troubleshooting—small but meaningful when debugging at 2 a.m. on-site.

Technical Specifications

Application Fields

This module tends to appear in wastewater treatment plants, HVAC control panels, and older manufacturing lines still running ABB  S7-300 PLCs. In many cases, engineers use it to interface low-power logic outputs with higher-load devices like contactors, solenoid valves, or alarm horns. You might notice that some users deploy it as part of safety interlock circuits where physical contact separation is required by local standards.

Advantages & Value

While not flashy, the value here lies in reliability and drop-in compatibility. If your plant already uses ABB  hardware, sourcing an OEM module like the 07KT97H3 can reduce configuration time and minimize documentation changes. Spare parts inventory stays simpler too. It’s not the fastest or smartest relay out there, but in critical applications where “it just works” matters more than features, it seems to be a solid choice.

Installation & Maintenance

Install in a clean, well-ventilated control cabinet meeting IP54 or better protection. Avoid placing near high-heat sources like drives or transformers—relay life drops noticeably above 60°C. Wiring should follow standard industrial practices: use ferrules, label all conductors, and keep power and signal lines separated. There’s no firmware to update, but periodic visual checks for discoloration or loose terminals are recommended. Calibration isn’t needed, though functional testing every 6–12 months helps catch early wear.

Quality & Certifications

The module carries CE and UL recognition, and complies with relevant EN and IEC standards for industrial control equipment (e.g., EN 61010). RoHS compliance confirms restricted substance limits are met. Siemens typically backs these components with a 1-year manufacturer warranty—aligned with our own 365-day coverage policy.

Our Order Placement Process and Guarantees

We keep common Siemens spares like the 07KT97H3 in stock whenever possible. Delivery usually takes about one week if available. Worst-case scenario—if we need to source it—it won’t take longer than a month. Payment is split: 50% upfront to secure the order, and the balance before shipment. We ship via FedEx, UPS, or DHL depending on destination and urgency. All units are tested before dispatch, and we’ll provide tracking details promptly.