The **JR28-R-DLFP115** is a high-power electronic component, specifically a **thermal overload relay** designed to work in conjunction with AC contactors. Its primary function is to protect electric motors from damage caused by overloads or phase failures. --- ### Technical Specifications The following table highlights the core electrical characteristics of the JR28 series, specifically the 115A frame size: | Parameter | Specification | | :--- | :--- | | **Model** | JR28-R-DLFP115 | | **Rated Current (In)** | 115 Amperes | | **Adjustment Range** | Typically adjustable (e.g., 80A - 115A) | | **Rated Voltage (Ue)** | Up to 690V AC | | **Tripping Class** | 10A (Standard industrial protection) | | **Auxiliary Contacts** | 1 NO (Normally Open) + 1 NC (Normally Closed) | | **Reset Mode** | Manual or Automatic (Switchable) | --- ### Key Electronic & Mechanical Features 1. **Bimetallic Actuation:** The core "electronic" logic is actually electromechanical. It uses bimetallic strips that bend when heated by excessive current. When the current exceeds the set threshold, the physical deformation of these strips triggers the internal mechanism to open the control circuit. 2. **Phase Failure Protection:** This device is sensitive to unbalanced loads. If one phase fails, the internal differential mechanism detects the uneven expansion of the bimetallic strips and trips the relay faster than a standard overload would. 3. **Adjustable Current Dial:** It features a potentiometer-style dial on the front face. This allows the user to calibrate the trip point based on the **Full Load Amps (FLA)** of the specific motor being protected. 4. **Auxiliary Control Circuit:** * **NC (95-96):** Wired in series with the contactor coil to cut power during a fault. * **NO (97-98):** Used for signaling (e.g., triggering a fault light or sending an input to a PLC). --- ### Connection Diagram Concept The unit is typically mounted directly to the bottom of a compatible AC contactor. ```text [ Power Source L1, L2, L3 ] | [ AC Contactor ] | [ JR28-R-DLFP115 ] <--- Protection Logic | [ AC Motor ] ``` ---