The **FTR-K3JB005W-HC** is a high-capacity, miniature power relay manufactured by **Fujitsu Components**. It is specifically designed for high-current switching in space-constrained environments, such as solar inverters and industrial power supplies. --- ### 1. Key Technical Specifications The following table outlines the critical electrical and mechanical parameters of the device: | Parameter | Specification | | :--- | :--- | | **Contact Arrangement** | 1 Form A (SPST-NO) | | **Coil Voltage** | 5V DC | | **Switching Current (Max)** | 33A | | **Switching Voltage (Max)** | 250V AC | | **Contact Material** | Silver Tin Oxide (AgSnO2) | | **Power Consumption** | Approx. 780 mW | | **Insulation Distance** | 8.5mm (Clearance/Creepage) | | **Dielectric Strength** | 5,000V AC (between coil and contacts) | --- ### 2. Part Number Breakdown Understanding the nomenclature helps identify the specific features of this variant: * **FTR-K3**: Series designation (High-capacity power relay). * **JB**: Specific contact structure/rating (Heavy duty). * **005**: Nominal coil voltage (5V DC). * **W**: Contact material/type (Standard power type). * **HC**: High Current version (optimized for 33A loads). --- ### 3. Core Features & Advantages * **High Inrush Capability:** Designed to handle significant surges without welding the contacts, making it ideal for capacitive or inductive loads. * **Safety Compliance:** Meets international standards for reinforced insulation, providing high galvanic isolation between the low-voltage control side (coil) and the high-voltage load side. * **Low Profile:** Despite its 33A rating, it maintains a compact PCB footprint, saving board real estate. * **Cadmium Free:** Uses Silver Tin Oxide contacts, which are environmentally friendly and compliant with RoHS regulations. --- ### 4. Common Applications Due to its high current rating and reliability, this relay is frequently found in: 1. **Solar Inverters:** Used as a grid-connection relay (AC side). 2. **Electric Vehicle (EV) Charging:** Integrated into Level 1 and Level 2 AC chargers. 3. **Uninterruptible Power Supplies (UPS):** Handling power path switching. 4. **Smart Grids:** Power distribution and smart meter switching.