CHANGEOVER PANEL A **changeover panel** (also known as a **transfer switch** or **automatic transfer switch** - ATS) is an essential component in an electrical system designed to switch the power supply from one source to another, typically between the main utility grid and a backup power source like a generator. It ensures that when the primary power source fails, the secondary power source (such as a generator) can automatically or manually take over without interruption. ### Key Features and Components of a Changeover Panel: 1. **Main Power Supply Input**: The primary electrical power source, usually from the utility grid, enters the changeover panel. 2. **Secondary Power Supply Input**: This is the backup power source, typically from a generator or an alternate power source, that can be switched to when the main supply fails. 3. **Transfer Switch**: The core component of a changeover panel, the transfer switch automatically or manually switches between the main and backup power sources. It disconnects the main supply when a failure is detected and connects the backup power. 4. **Circuit Breakers**: Like in a distribution panel, circuit breakers are used to protect the wiring and electrical equipment by disconnecting the circuits in case of overloads or faults. 5. **Control Mechanism**: - **Manual Changeover**: In some panels, an operator needs to manually switch between the main and backup sources using a switch or a lever. - **Automatic Changeover**: In an automatic transfer switch (ATS), the panel detects a power failure and automatically switches to the backup power supply without any human intervention. 6. **Indicators and Alarms**: Some changeover panels include visual indicators, like LED lights, and alarms to show the status of the power sources (e.g., whether the backup generator is in use or whether there’s a fault). 7. **Neutral and Ground Bus Bars**: These bars provide a safe return path for the electrical current and ensure proper grounding of the system. ### Types of Changeover Panels: 1. **Manual Changeover Panel**: - Requires the operator to manually switch from the main power source to the backup source (generator) in the event of a power failure. - Common in smaller installations or places where automatic transfer is not critical. 2. **Automatic Changeover Panel (ATS)**: - **Automatic Transfer Switch** (ATS) automatically detects a failure in the main supply and switches to the backup power source without the need for human intervention. - This type is commonly used in critical applications such as hospitals, data centers, factories, and residential properties with backup generators. ### Purpose and Benefits: - **Uninterrupted Power Supply**: Changeover panels ensure that critical systems remain operational by switching to a backup power source in case of a failure in the primary power grid. - **Automatic or Manual Control**: They offer flexibility in either manual operation (for non-critical systems) or automatic operation (for critical systems). - **Safety**: Prevents back-feeding, which can occur when both power sources are connected simultaneously, potentially damaging the equipment and causing safety hazards. - **Convenience**: They are often used in facilities that require 24/7 power continuity, ensuring that when the utility power fails, the backup generator takes over seamlessly. ### Applications: - **Residential**: Homes with backup generators. - **Commercial**: Businesses that cannot afford downtime (e.g., stores, offices). - **Industrial**: Manufacturing plants or facilities that need continuous power for production or machinery. - **Critical Infrastructure**: Hospitals, data centers, communication facilities, and other systems where power interruptions can have severe consequences. In summary, a **changeover panel** is vital for ensuring a smooth and safe transition between primary and secondary power sources, particularly in environments where power continuity is essential.