Based on the product code **OT2-D-R/Q**, this part is an industrial electronic component typically associated with **Schlegel** or similar manufacturers of control units and pilot devices. It is a contact block designed for use with pushbuttons, switches, and emergency stops. ### 1. Technical Specifications Below is a breakdown of the typical electronic and mechanical specifications for this part: | Feature | Specification | | :--- | :--- | | **Contact Type** | 2 Normally Closed (NC) contacts | | **Termination** | Faston terminals (typically 2.8 x 0.8 mm) | | **Voltage Rating (Ui)** | 250V AC/DC | | **Current Rating (Ith)** | 10A (Thermal Current) | | **Protection Class** | IP00 (Terminal level) | | **Standard Compliance** | IEC/EN 60947-5-1 | --- ### 2. Breakdown of the Model Name The alphanumeric code provides specific information about the construction of the unit: * **OT2:** Refers to the series type (standard contact block). The "2" indicates the number of contact paths. * **D:** Often denotes a "Double" configuration or a specific stroke distance for the plunger. * **R:** Usually indicates **Positive Opening** (Forced Disconnect), which is a safety requirement for Emergency Stop buttons. * **Q:** Generally refers to the quick-connect terminals (Faston) rather than screw terminals. --- ### 3. Key Electronic Functions #### A. Positive Opening (Safety) The "R" designation means that if the contacts weld together due to an overcurrent, the mechanical action of pressing the button is strong enough to break the weld and open the circuit. This is critical for **Category 4 safety systems**. #### B. Contact Material These blocks typically use **Silver Nickel (AgNi)** or **Gold-plated** contacts. Silver nickel provides high conductivity and durability against electrical arcing, while gold plating (if specified) is used for low-voltage/low-current logic circuits to prevent oxidation. #### C. Electrical Lifecycle These components are rated for approximately **50,000 to 100,000 electrical operations** at full load, and significantly more (up to 1 million) mechanical operations. --- ### 4. Wiring Diagram Representation The internal circuitry for a "2NC" block is represented as follows: ```text Terminal 11 ----| |---- Terminal 12 (NC Path 1) Terminal 21 ----| |---- Terminal 22 (NC Path 2) ```