The **ESS22-T** (Electronic Selective Storage) is a high-performance, pluggable electronic circuit breaker designed specifically for the protection of automation systems and DC 24V power supplies. It combines physical isolation with electronic monitoring. --- ### 1. Key Electronic Components and Architecture The ESS22-T operates using a combination of solid-state electronics and mechanical disconnection. | Component | Function | | :--- | :--- | | **Current Sensor** | Continuously monitors the load current via a low-resistance shunt. | | **Control Logic (IC)** | An integrated circuit that evaluates current levels against a time-current curve. | | **Power MOSFET** | Acts as the high-speed switch to disconnect the load during an overload. | | **Bimetal/Solenoid** | Provides physical isolation (galvanic isolation) for safety. | | **Signal Contacts** | Auxiliary contacts (11-12/13-14) for remote status monitoring. | --- ### 2. Technical Specifications | Parameter | Specification | | :--- | :--- | | **Rated Voltage** | DC 24 V (18...32 V) | | **Current Ratings** | 0.5 A to 10 A (Fixed ratings) | | **Trip Curves** | Physical trip (thermal-magnetic style) + Electronic limit | | **Status Indication** | Multicolored LED (Green: OK, Orange: Warning, Red: Tripped) | | **Isolation** | Physical isolation in "OFF" or "Tripped" state | --- ### 3. Protection Characteristics The electronic design allows the ESS22-T to distinguish between **Inrush Currents** and **Actual Faults**: 1. **Electronic Current Limiting:** When a short circuit occurs, the electronics limit the current to approximately **1.1 to 1.5 times** the rated current. This prevents the DC 24V power supply from collapsing. 2. **Delayed Trip:** If the overload persists beyond a predefined time (usually 100ms to several seconds depending on the overload factor), the unit trips electronically. 3. **Physical Disconnection:** After electronic shutdown, the device ensures a physical break in the circuit, meeting safety standards for isolation. --- ### 4. Comparison: ESS22-T vs. Standard MCBs | Feature | ESS22-T (Electronic) | Standard MCB (Thermal-Magnetic) | | :--- | :--- | :--- | | **Selectivity** | High (protects specific branches) | Low (can cause total PSU shutdown) | | **Reset** | Manual toggle switch | Manual toggle switch | | **Input Sensitivity** | Very precise electronic monitoring | Dependent on temperature/heat | | **Power Supply Safety** | Prevents voltage dips | May cause voltage dips during shorts | ---