Mastering ATS Panel Wiring: Generator Changeover Switch

Table of Contents

1. Introduction
2. Understanding Standby Generator Power Connection
3. Components Required for Automatic Transfer Switch Panel
4. Contactor for 3-Phase 400 Volt Supply
5. Power Connection from Generator to Load
6. Timer and Relay Components
7. Connection Wiring for Grid Power
8. Connection Wiring for Generator Power
9. Control Circuit Wiring
10. Power Supply to Load
11. Operation of Power Transfer
12. Manual Starting of Generator
13. Generator Auto Start and Auto Stop Connections

Understanding Standby Generator Power Connection

In this article, we will discuss how standby generator power can be connected to the load automatically when grid power is interrupted. We will explore the basics of an automatic transfer switch panel and how it works. This knowledge will allow you to modify the setup according to your specific requirements.

Introduction

Standby generators are essential for providing backup power in case of an electrical outage. However, simply having a generator is not enough. It needs to be connected to the load automatically to ensure uninterrupted power supply. This is where an automatic transfer switch panel comes into play.

Components Required for Automatic Transfer Switch Panel

To connect the standby generator power to the load automatically, several components are required. These include a contactor for the three-phase 400 volt supply from the grid, two eight pin timers (one for grid power and the other for generator power), an eight pin DPDT relay (Double Pole Double Throw), and two pole MCBs (Miniature Circuit Breakers) for grid and generator sides.

Contactor for 3-Phase 400 Volt Supply

The contactor is responsible for connecting the load with the grid power when it is in the "on" position. However, when the standby generator is started, power will only be available up to the L1, L2, and L3 terminals, as the generator contactor will be in the "off" position.

Power Connection from Generator to Load

When the grid power goes off, the power from the generator needs to be automatically connected to the load. This is achieved through the use of timers and relays. The timers and relays have multiple inlet and outlet points, each designed for specific connections.

Timer and Relay Components

The timers and relays used in the automatic transfer switch panel have specific connection points. Power is supplied through points 2 and 7, and the common points are 1 and 8. The outlet points, 3, 4, 5, and 6, are used to control the position of the relay or timer depending on the power supply.

Connection Wiring for Grid Power

The connection wiring on the grid side includes a single-phase 220 volt supply, a grid MCB (Miniature Circuit Breaker), a relay, and a grid timer. The relay is powered by the supply from the breaker, and its output is connected to the grid timer power supply. The relay and timer are interlinked to ensure the transfer of power from the grid to the load.

Connection Wiring for Generator Power

On the generator side, the connection wiring includes a single-phase 220 volt supply, a generator MCB, a relay, and a generator timer. The power from the generator is connected to the common port of the relay, and the timer is powered through connection number 4. The generator timer outlet port 6 is connected to the A1 of the generator contactor, ensuring the interlocking safety of the contactors.

Control Circuit Wiring

The control circuit wiring on both the grid and generator sides is completed by connecting the neutral wires to the A2 terminals of the contactors. This ensures the completion of the circuit and allows for the control of power supply to the load.

Power Supply to Load

With the control circuit wiring in place and the two breakers switched on, the power supply to the load can be achieved. The grid side control power breaker provides power to the relay and the grid timer, allowing for the transfer of power from the grid to the load.

Operation of Power Transfer

When the grid power is interrupted, the automatic transfer of power to the generator takes place. The relay gets power, and the grid timer receives power through the relay. After the set delay time, power is transferred to the A1 of the grid contactor, connecting the load to the generator power. The interlocking of the contactors ensures the safety of the system.

Manual Starting of Generator

To initiate the power supply from the generator, it needs to be started manually. Once started, the generator powers number one common port of the relay, allowing for the connection to the generator timer. After the set delay time, power is transferred to the A1 of the generator contactor, providing power to the load.

Generator Auto Start and Auto Stop Connections

This article covers the basic setup of an automatic transfer switch panel for connecting standby generator power to the load automatically. However, it does not include the connections for generator auto start and auto stop. These connections will be discussed in a separate video.

In summary, an automatic transfer switch panel is crucial for ensuring uninterrupted power supply when grid power is interrupted. By understanding the components and their wiring, you can create a reliable system that automatically switches between grid and generator power as needed.

Pros:

• Provides uninterrupted power supply during grid power outages
• Allows for automatic switching between grid and generator power
• Flexible setup that can be modified according to specific requirements

Cons:

• Manual starting of the generator is required
• Auto start and auto stop connections are not covered in this article

Highlights

• Understanding the basics of an automatic transfer switch panel
• Connecting standby generator power to the load automatically
• Components required for an automatic transfer switch panel
• Wiring connections for grid power and generator power
• Control circuit wiring to complete the system
• Operation of power transfer from grid to generator and vice versa
• Manual starting of the generator
• Pros and cons of an automatic transfer switch panel

FAQ

Q: What is an automatic transfer switch panel? A: An automatic transfer switch panel is a system that automatically connects standby generator power to the load when grid power is interrupted.

Q: What are the components required for an automatic transfer switch panel? A: The components include a contactor, timers, relays, MCBs, and wiring connections for grid power and generator power.

Q: How does the automatic transfer switch panel work? A: The panel uses timers and relays to control the power transfer between the grid and the generator. It ensures that power is automatically switched to the generator when grid power is interrupted and back to the grid when it's restored.

Q: Is the starting of the generator automatic? A: No, the starting of the generator is manual in this setup. Auto start and auto stop connections are not covered in this article.

Q: What are the advantages of an automatic transfer switch panel? A: The advantages include uninterrupted power supply during grid power outages and the ability to automatically switch between grid and generator power.

Q: Can the setup be modified according to specific requirements? A: Yes, the setup can be modified according to specific requirements by adding or adjusting components and wiring connections.