Feeder is designed mainly from the point of view of its current carrying capacity.

Introduction:
A feeder is an essential component of an electrical distribution system that carries electrical power from the substation to various electrical loads. It plays a crucial role in delivering the required amount of electricity to different areas, buildings, or machines. The design of a feeder takes into consideration several factors to ensure efficient and safe power transmission.

Current Carrying Capacity:
The current carrying capacity of a feeder refers to the maximum amount of electrical current that it can safely carry without overheating or causing any damage. This capacity is determined by considering the following factors:

1. Load Requirements: The feeder should be capable of supplying the maximum expected load demand without exceeding its current carrying capacity. The load requirements may vary based on the type of electrical devices connected to the feeder.

2. Wire Size: The size of the feeder wire is selected based on the maximum current that it needs to carry. Larger wire sizes have lower resistance and can handle higher currents without excessive voltage drops or heating.

3. Conductor Material: The choice of conductor material also affects the current carrying capacity. Copper is a commonly used material for feeders due to its high conductivity and superior current carrying capacity compared to aluminum.

4. Temperature Rise: The design of the feeder considers the maximum allowable temperature rise due to the flow of current. Excessive temperature rise can lead to insulation degradation and potential fire hazards.

5. Ambient Temperature: The ambient temperature of the installation location affects the current carrying capacity of the feeder. Higher ambient temperatures reduce the capacity, and appropriate derating factors are applied to ensure safe operation.

Other Considerations:
While current carrying capacity is the primary focus in feeder design, other factors are also taken into account to ensure reliable and efficient power transmission. These factors include:

1. Voltage Drop: Although not the main design consideration, voltage drop is also assessed to ensure that the electrical devices connected to the feeder receive an acceptable voltage level for proper operation.

2. Operating Voltage: The feeder design takes into account the operating voltage of the electrical system to ensure compatibility and safe power transmission.

3. Operating Frequency: The operating frequency of the electrical system is considered to ensure the feeder can handle the specific frequency without any adverse effects.

Conclusion:
In conclusion, the design of a feeder is primarily focused on its current carrying capacity. This capacity is determined by considering factors such as load requirements, wire size, conductor material, temperature rise, and ambient temperature. While other factors like voltage drop, operating voltage, and operating frequency are also considered, they are secondary in comparison to the current carrying capacity.