Feeder line is part of an electric distribution network. An electrical wiring circuit in a building which carries power from a transformer or switch gear to a distribution panel. Different feeders are connected to the feeder bus to feeds different loads like, motor loads, lighting loads, industrial machinery loads, air conditioner loads, transformer cooling system loads etc. All feeders are primarily protected by switch fuse unit and in addition to that, depending upon the types of load connected to the feeders, the different switchgear devices are chosen for different feeders.
Types of Feeder:
- Motor Feeder
- Industrial Machinery Load Feeder
- Lighting Load Feeder
Motor feeder should be protected against over load, short circuit, over current up to locked rotor condition and single phasing.
Industrial Machinery Load Feeder:
Feeder connected industrial machinery load like oven, electroplating bath etc. are commonly protected by MCCB and switch fuse units
Lighting Load Feeder:
This is protected similar to industrial machinery load but additional earth leakage current protection is provided in this case to reduce any damage to life and property that could be caused by harmful leakages of current and fire
In LV switchgear system, electrical appliances are protected against short circuit and over load conditions by electrical fuses or electrical circuit breaker. However, the human operator is not adequately protected against the faults occurs inside the appliances. The problem can be overcome by using earth leakage circuit breaker. This operates on low leakage current. The earth leakage circuit breaker can detect leakage current as low as 100 mA and is capable of disconnecting the appliance in less than 100 msec.