The terms "feeder" and "bus bar" are commonly used in electrical power distribution systems, but they serve different purposes. Here's a detailed explanation of both terms and their differences:
### 1. **Feeder:**
- **Definition:** A **feeder** is an electrical conductor (typically a cable or overhead line) that carries power from the generating source (such as a power plant, transformer, or substation) to the distribution network or load centers.
- **Purpose:** The primary function of a feeder is to deliver electrical power to different distribution points. It connects the source (like a substation) to a secondary distribution point, such as a distribution board or smaller substations.
- **Load Distribution:** Feeders typically supply power to multiple circuits or branches. They do not have branches of their own, and their purpose is to transfer power over long distances with minimal losses.
- **Design:** Feeders are designed to handle high currents and are usually protected by circuit breakers, relays, or fuses to avoid overloading.
- **Location:** Feeders are typically installed between the main power source and the distribution points, and they serve large loads (like residential or industrial areas).
- **Example:** In a power distribution system, a feeder may carry power from a main substation to smaller local substations or transformers, from which electricity is further distributed to homes or businesses.
### 2. **Bus Bar:**
- **Definition:** A **bus bar** is a metallic strip or bar made of conductive materials like copper or aluminum, used to distribute electrical power within a switchboard, substation, or other distribution equipment.
- **Purpose:** A bus bar’s primary role is to collect incoming power from a feeder and distribute it to various outgoing circuits (such as feeders or branch circuits). It acts as a central point where multiple circuits can be connected and can distribute power to various parts of the system.
- **Load Distribution:** Bus bars are used to distribute electricity to multiple outgoing feeders or circuits, making it easier to organize and control the distribution of power.
- **Design:** Bus bars are usually solid, flat, or rectangular conductors and are installed inside panels, switchboards, or distribution boards. They are highly conductive, low-resistance, and can handle large currents without significant voltage drops.
- **Location:** Bus bars are typically found inside electrical panels, substations, or switchgear, where they serve as a junction for power distribution.
- **Example:** In a substation, the bus bar is the point where incoming feeders bring power in, and multiple outgoing feeders distribute the power to various load points like transformers or distribution circuits.
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### **Key Differences Between Feeder and Bus Bar:**
| **Aspect** | **Feeder** | **Bus Bar** |
|-----------------------|----------------------------------------------|----------------------------------------------|
| **Function** | Transmits power from a source to a distribution point or another substation. | Collects and distributes power to multiple circuits within a substation or panel. |
| **Location** | Found between power sources (e.g., substation, transformer) and load centers. | Found inside switchboards, distribution panels, or substations. |
| **Current Capacity** | Designed to handle high current over long distances. | Designed to distribute high currents but within a panel or local system. |
| **Configuration** | Typically consists of cables or overhead lines. | Typically a solid bar made of conductive materials like copper or aluminum. |
| **Purpose** | Supplies power to various points in the system (e.g., substations, transformers). | Distributes power to multiple outgoing circuits within a localized area. |
| **Protection** | Protected by circuit breakers or relays to prevent overloads. | Part of the internal structure of switchgear, and protection is applied at feeder or branch circuit levels. |
| **Physical Form** | Cables or overhead lines. | Solid metallic strip (copper, aluminum). |
### Summary:
- **Feeder**: Transports electricity from one point (such as a substation) to another (e.g., distribution board) over relatively long distances.
- **Bus Bar**: Distributes electricity within a control panel, substation, or distribution board to different feeders or circuits.
In simple terms, think of a **feeder** as a highway that moves electricity across regions, while a **bus bar** is more like a junction point where different roads (circuits) meet, allowing power to be distributed to different locations efficiently.