New ArticlesMOSFET as a SwitchRelationship of Line and Phase Voltages and Currents in a Star Connected System555 Timer and 555 Timer WorkingBistable MultivibratorMonostable MultivibratorAstable MultivibratorClosely Related ArticlesElectrical Power Distribution System | Radial and Ring Main Electrical Switchgear ProtectionElectrical Isolator or Electrical Isolation SwitchLow Voltage Switchgear or LV SwitchgearMedium Voltage Switchgear High Voltage SwitchgearEquipment Earthing GIS or Gas Insulated SwitchgearMetal Enclosed SwitchgearVacuum Switchgear ZnO Gapless Lightning Arrester or Surge ArresterBIL or Basic Insulation Level Definition Table and CalculationWhat is arc ? | Arc in Circuit BreakerArc Interruption TheoryVacuum Arc or Arc in VacuumElectrical Circuit Breaker | Operation and Types of Circuit BreakerCircuit Breaker MaintenanceHigh Voltage Testing | Low Frequency Constant DC High Frequency Surge or Impulse TestSulfur Hexafluoride | SF6 Gas PropertiesRoutine Tests of Circuit BreakersRemote Controlling of Circuit Breaker by MicrocontrollerCircuit Breaker Operation Rating of Circuit Breaker |

Short Circuit Breaking Making CurrentShort Circuit Current of Circuit BreakerAir Circuit Breaker Air Blast Circuit BreakerOil Circuit Breaker Bulk and Minimum Oil Circuit BreakerTypes and Operation of SF6 Circuit BreakerVacuum Circuit Breaker or VCB and Vacuum InterrupterResidual Current Circuit BreakerElectrical Fuse HRC Fuse High Rupturing CapacityMiniature Circuit Breaker or MCBWorking Principle of Earth Leakage Circuit Breaker ELCB | Voltage and Current ELCB | Electrical Power Distribution SystemThe main function of an electrical power distribution system is to provide power to individual consumer premises. Distribution of electric power to different consumers is done with much low voltage level. Distribution of electric power is done by distribution networks. Distribution networks consist of following main parts The transmitted electric power is stepped down is substations, for primary distribution purpose. Now these stepped down electric power is fed to the distribution transformer through primary distribution feeders.

Over head primary distribution feeders are supported by mainly supporting iron pole (preferably rail pole). The conductors are strand aluminum conductors and they are mounted on the arms of the pole by means of pin insulators. Some times in congested places, underground cables may also be used for primary distribution purposes. Distribution transformers are mainly 3 phase pole mounted type. The secondary of the transformer is connected to distributors. Different consumers are fed electric power by means of the service main. These service mains are tapped from different points of distributors. The distributors can also be re-categorized by distributors and sub distributors. Distributors are directly connected to the secondary of distribution transformers whereas sub distributors are tapped from distributors. Service main of the consumers may be either connected to distributors or sub distributors depending upon the position and agreement of consumers. In this discussion of electrical power distribution system, we have already mentioned about both feeders and distributors.

Both feeder and distributor carry the electrical load, but they have one basic difference. Feeder feeds power from one point to another without being tapped from any intermediate point. As because there is no tapping point in between, the current at sending end is equal to that of receiving end of the conductor. how to determine ac window unit sizeThe distributors are tapped at different points for feeding different consumers; gree split air conditioner user manualand hence the current varies along their entire length.ac unit fan replacement Radial Electrical Power Distribution System In early days of electrical power distribution system, different feeders were radially come out from the substation and connected to the primary of distribution transformer directly.

But radial electrical power distribution system has one major drawback that in case of any feeder failure, the associated consumers would not get any power as there was no alternative path to feed the transformer. In case of transformer failure also, the power supply is interrupted. In other words the consumer in the radial electrical distribution system would be in darkness until the feeder or transformer was rectified. Ring Main Electrical Power Distribution System The drawback of radial electrical power distribution system can be overcome by introducing a ring main electrical power distribution system. Here one ring network of distributors is fed by more than one feeder. In this case if one feeder is under fault or maintenance, the ring distributor is still energized by other feeders connected to it. In this way the supply to the consumers is not affected even when any feeder becomes out of service. In addition to that the ring main system is also provided with different section isolates at different suitable points.

If any fault occurs on any section, of the ring, this section can easily be isolated by opening the associated section isolators on both sides of the faulty zone. In this way, supply to the consumers connected to the healthy zone of the ring, can easily be maintained even when one section of the ring is under shutdown. The number of feeders connected to the ring main electrical power distribution system depends upon the following factors. If it is more, then more numbers of feeders feed the ring. It length is more, to compensate the voltage drop in the line, more feeders to be connected to the ring system. The number of feeders connected to the ring also depends upon the permissible allowable, voltage drop of the line. The sub distributors and service mains are taken off may be via distribution transformer at different suitable points on the ring depending upon the location of the consumers. Sometimes, instead of connecting service main directly to the ring, sub distributors are also used to feed a group of service mains where direct access of ring distributor is not possible.