The Siemens 3RH2921-1DA02 Lateral Auxiliary Contact Block is a high-quality industrial accessory designed to expand the auxiliary contact capabilities of Siemens contactors and contactor relays. As part of the trusted Siemens SIRIUS 3RH29 Series, the 3RH2921-1DA02 provides an efficient and space-saving solution for adding additional control, monitoring, signaling, and interlocking functions within industrial automation systems. Featuring a 2 Normally Closed (2NC) contact configuration, this auxiliary contact block is ideal for safety interlocking circuits, fault indication systems, shutdown controls, and advanced automation applications.
The Siemens 3RH2921-1DA02 Auxiliary Contact Block is specifically engineered for side mounting on compatible Siemens contactors and relays. Its lateral mounting design allows installation on either the left or right side of the device, maximizing panel space while maintaining easy access for wiring and maintenance. This compact and modular construction enables engineers and panel builders to expand control functionality without redesigning existing control systems.
In industrial automation environments, auxiliary contacts are essential for providing status feedback, electrical interlocking, PLC communication, alarm signaling, and safety monitoring. The 3RH2921-1DA02 enhances these capabilities by offering two additional normally closed contacts that can be integrated into control circuits for monitoring equipment status, preventing unintended operation, and implementing fail-safe logic functions. The dual NC configuration is particularly valuable in applications where equipment shutdown and safety interlocking are critical requirements.
One of the major advantages of the Siemens 3RH2921-1DA02 is its 2NC contact arrangement, which allows users to create multiple interlocking paths within a control system. These contacts can be used for emergency stop circuits, fault monitoring systems, motor protection logic, machine safety functions, and control circuit supervision. By expanding the available auxiliary contacts, the device helps improve overall system safety and operational reliability.
The auxiliary contact block utilizes reliable screw terminal connections, ensuring secure electrical wiring and long-term performance even in demanding industrial environments. Screw terminals remain a preferred connection method for industrial control systems because they provide excellent mechanical stability, vibration resistance, and ease of maintenance. This design ensures dependable contact performance throughout the service life of the equipment.
Designed according to Siemens' modular SIRIUS platform concept, the 3RH2921-1DA02 Auxiliary Contact Block is compatible with a wide range of Siemens 3RT contactors and 3RH contactor relays. This compatibility allows system designers to standardize components across multiple projects while reducing inventory requirements and simplifying maintenance procedures. The modular architecture also enables quick upgrades and control circuit expansion without major modifications.
The Siemens SIRIUS 3RH2921-1DA02 is manufactured to meet stringent industrial quality standards and offers exceptional durability. It is engineered for high mechanical endurance and dependable switching performance, making it suitable for continuous operation in manufacturing facilities, machine building applications, process industries, infrastructure projects, HVAC systems, water treatment plants, and motor control centers.
Its compact dimensions make the 3RH2921-1DA02 an excellent choice for modern control panels where space optimization is essential. Despite its small footprint, the auxiliary contact block delivers robust performance and seamless integration into Siemens control systems. The snap-on installation mechanism further reduces assembly time and simplifies replacement procedures during maintenance operations.
Industrial automation professionals rely on the Siemens 3RH2921-1DA02 Lateral Auxiliary Contact Block for applications involving safety interlocking, fault signaling, PLC monitoring, machine protection, motor control circuits, and process automation systems. The dual normally closed contacts provide enhanced control flexibility while maintaining the reliability expected from Siemens industrial products.
At SBsmart.in, we supply genuine Siemens industrial automation components trusted by engineers, OEMs, panel builders, electrical contractors, and maintenance professionals across industries. When you choose the Siemens 3RH2921-1DA02 Auxiliary Contact Block, you receive an authentic Siemens accessory designed for dependable performance, easy installation, and long-term operational reliability.
Whether you are upgrading an existing control panel, expanding a motor control center, or designing a new automation system, the Siemens 3RH2921-1DA02 provides a practical and cost-effective solution for increasing auxiliary contact capacity while maintaining Siemens-quality engineering standards.
| Specification | Details |
|---|---|
| Product Name | Lateral Auxiliary Contact Block |
| Manufacturer | Siemens |
| Series | SIRIUS 3RH29 |
| Model Number | 3RH2921-1DA02 |
| SKU | 3RH2921-1DA02 |
| Product Type | Auxiliary Contact Block |
| Mounting Position | Left or Right Side Mounting |
| Contact Configuration | 2NC (2 Normally Closed) |
| Number of Contacts | 2 |
| Contact Type | Auxiliary Contacts |
| Terminal Type | Screw Terminals |
| Mounting Method | Snap-On |
| Compatible Devices | Siemens 3RT Contactors & 3RH Relays |
| Rated Insulation Voltage (Ui) | 690 V |
| Rated Impulse Withstand Voltage (Uimp) | 6 kV |
| Width | Approx. 10 mm |
| Height | Approx. 57 mm |
| Depth | Approx. 66 mm |
| Mechanical Endurance | Up to 10 Million Operations |
| Operating Temperature | -25°C to +60°C |
| Storage Temperature | -55°C to +80°C |
| Standards Compliance | IEC 60947-4-1, IEC 60947-5-1 |
| Application | Interlocking, Monitoring & Control Expansion |
| Product Family | Siemens SIRIUS Accessories |
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