Across the line (ATL) wiring is a common electrical connection for motors, pumps, and other heavy-duty machinery. In this article, we will discuss the basics of ATL wiring, how it works, and its applications.
What is Across the Line Wiring?
Across the line wiring is an electrical connection where the motor or any heavy-duty equipment is connected directly to the source voltage. The voltage rating of the motor is typically 110 volts, 220 volts, or 440 volts.
The main purpose of ATL wiring is to start the motor, and once it reaches its desired speed, the switch is then turned off. This process of starting and stopping the motor using a switch is known as direct-on-line (DOL) starting.
ATL wiring is simple to install, requires less wiring, and less expensive than other types of starting methods. It is used in applications where the starting torque requirements are not high or where the equipment is not subjected to high loads.
Applications of Across the Line Wiring
ATL wiring is commonly used in applications like motor-driven pumps, fans, conveyors, and air compressors. There are many other applications where this type of wiring is used, but these are the most common ones.
Let us now look at the wiring diagram for ATL wiring.
Across the Line Wiring Diagram
The basic ATL wiring diagram consists of a power source, switch, and the motor. The switch is used to connect or disconnect the power source from the motor.
| Power Source | Switch | Motor |
|---|---|---|
| Three-phase power supply | Motor starter switch | Three-phase induction motor |
The switch used in ATL wiring is a motor starter switch. This switch is designed to protect the motor from overload, overcurrent, and short circuits. The motor starter switch contains an overload relay, contactor, and other protection devices.
The wiring diagram for the ATL connection is very simple. The three-phase power supply is connected to the motor starter switch. The output of the motor starter switch is then connected to the three-phase induction motor.
How Does Across the Line Wiring Work?
When the motor starter switch is turned on, the power supply is connected to the motor. The motor then starts and draws a high current. The overload relay in the motor starter switch monitors the current drawn by the motor.
If the current drawn by the motor exceeds the set limit, the overload relay trips and disconnects the power supply from the motor. This protects the motor from damage due to overcurrent or overload.
When the motor reaches its desired speed, the switch is turned off, and the motor stops.
FAQ
What is the difference between ATL and Y-Δ Starting?
ATL starting is a simple and inexpensive starting method used in applications where the starting torque requirements are not high. Y-Δ starting, on the other hand, is used in applications where the starting torque requirements are high. Y-Δ starting is more expensive than ATL starting but is more efficient and provides a higher starting torque.
How do I choose the right motor starter switch for ATL wiring?
The motor starter switch for ATL wiring should be rated for the same voltage as the motor. It should also have a suitable overload protection relay and should be able to handle the starting current of the motor. Always consult with a certified electrician or engineer before selecting the motor starter switch.
Can ATL wiring be used with single-phase motors?
No, ATL wiring cannot be used with single-phase motors since they require a different type of starting method.
Is ATL wiring safe?
Yes, ATL wiring is safe as long as the motor starter switch used in the wiring is rated for the voltage and current of the motor. It is also important to follow all electrical safety guidelines and regulations when installing and operating ATL wiring.
Conclusion
Across the line wiring is a simple and inexpensive starting method used in many applications where the starting torque requirements are not high. It is essential to choose the right motor starter switch and follow all electrical safety guidelines and regulations when installing and operating ATL wiring.
We hope this article has provided you with a better understanding of ATL wiring, how it works, and its applications.
