The **HDF36070** is a high-performance, industrial-grade molded case circuit breaker (MCCB) manufactured by **Schneider Electric** under the **Square D PowerPact H-Frame** series. It is designed to protect electrical systems from damage caused by overloads and short circuits. ### 1. Technical Specifications The following table highlights the core electronic and mechanical parameters of the HDF36070: | Parameter | Specification | | :--- | :--- | | **Product Type** | Circuit Breaker | | **Frame Type** | H-Frame | | **Current Rating** | 70 Amperes | | **Voltage Rating** | 600V AC / 250V DC | | **Number of Poles** | 3-Pole | | **Interrupting Rating** | 25 kA at 480V / 18 kA at 600V | | **Trip Unit Technology** | Thermal-Magnetic | | **Mounting Mode** | Unit Mount (Bolt-on) | --- ### 2. Key Electronic Components & Features #### A. Thermal-Magnetic Trip Unit Unlike purely electronic trip units found in larger frames (like the P-frame), the HDF36070 uses a **Thermal-Magnetic** mechanism: * **Thermal Element:** Uses a bimetallic strip that bends when heated by overcurrent, providing a time-delay trip for sustained overloads. * **Magnetic Element:** Uses an internal electromagnet that reacts instantaneously to high-level short circuits to prevent catastrophic equipment failure. #### B. Termination and Connectivity The HDF36070 is equipped with **I-Line** or standard mechanical lugs, depending on the specific sub-model. The electronic integrity of the connection is maintained through: * **AL150HD Lugs:** These accept copper or aluminum wiring (typically #14 AWG to 3/0 AWG). * **Phase Connections:** Standard ABC phasing for 3-phase industrial power distribution. #### C. Accessory Compatibility The breaker features internal slots for various electronic add-on modules: * **Shunt Trip:** Allows the breaker to be tripped remotely via an electrical signal. * **Auxiliary Switches:** Provides remote status indication (Open/Closed) to a PLC or monitoring system. * **Undervoltage Release (UVR):** Automatically trips the breaker if the supply voltage drops below a specific threshold. --- ### 3. Application and Usage This breaker is commonly used in commercial and industrial settings for: 1. **Motor Branch Circuits:** Protecting individual motors from phase-to-phase shorts. 2. **Control Panels:** Serving as the main or branch disconnect. 3. **HVAC Systems:** High-voltage protection for industrial chillers and heaters.