The part number **8736SDO2V02H31S** refers to a specific configuration of a **Schneider Electric (Square D)** NEMA Reversing Magnetic Starter. These are heavy-duty industrial components used to control the direction and operation of electric motors. --- ### Part Number Breakdown To understand the electronic and mechanical capabilities, here is a breakdown of the nomenclature: | Code | Component Segment | Description | | :--- | :--- | :--- | | **8736** | Class Type | NEMA Type S Reversing Magnetic Starter. | | **S** | Size | NEMA Size 2 (Rated for higher horsepower/amperage than Size 0 or 1). | | **D** | Enclosure | NEMA 1 General Purpose Enclosure (Standard indoor use). | | **O** | Open/Closed | Open style (usually refers to the internal chassis mount). | | **2** | Poles | 3-Pole configuration (for 3-phase motors). | | **V02** | Coil Voltage | 120V AC @ 60Hz / 110V AC @ 50Hz control circuit. | | **H31** | Overload Relay | Solid-State Overload Relay (Motor Logic) Class 10/20. | | **S** | Special Feature | Separate control circuit (isolated supply for the coil). | --- ### Technical Specifications | Feature | Specification | | :--- | :--- | | **Phase** | 3-Phase | | **Current Rating** | 45 Amperes | | **Max Horsepower** | 10 HP @ 200V / 15 HP @ 230V / 25 HP @ 460-575V | | **Relay Type** | Motor Logic Solid State (Adjustable trip settings) | | **Control Voltage** | 120 VAC (requires external source or transformer) | | **Reset Type** | Manual/Automatic (selectable on the relay) | --- ### Key Electronic Components 1. **Reversing Contactors:** Consists of two mechanically interlocked contactors. One manages the forward rotation, and the other manages reverse by swapping two of the three incoming power phases. 2. **Solid-State Overload Relay (H31):** Unlike traditional thermal bimetallic strips, this electronic relay monitors current flow with high precision. It provides protection against phase loss, phase unbalance, and sustained overcurrent. 3. **Mechanical Interlock:** A safety mechanism that physically prevents both the "Forward" and "Reverse" contactors from closing at the same time, which would cause a direct short circuit. 4. **Auxiliary Contacts:** Used for signaling other logic controllers (like a PLC) or for "seal-in" circuits to keep the motor running after a momentary button press. --- ### Wiring Logic Example For the **V02** coil (120V), the control wiring typically follows this logic: ```mermaid graph LR A[120V Hot] --> B[Stop Button] B --> C[Forward Start] B --> D[Reverse Start] C --> E[Forward Coil] D --> F[Reverse Coil] E --> G[Neutral] F --> G ```