bus zone protection is a unit protection meaning a protection with a restricted zone therefore does not need to be coordinated with other time based protections . Course Overview. This course is intended to assist the user to find their way around the schemes that are supplied by Powertech SI to ESKOM. The schemes . When we examine electrical protection schemes, the best place to start is with electrical bus protections – overcurrent, differential, undervoltage.

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That is a current in the relay indicates a fault within the protected zone and initiates opening of the generator breaker CB 1 and CB 2 and each of the line breakers CB 3CB 4 and CB 5 including the bus breaker CB 6. It is based in simple circulating current principle that during normal load conditions or external fault conditions, the sum of currents entering the bus equals the sum of the currents leaving the busbas, i.

Discrimination between faults in its own protective zone and faults elsewhere. Moreover, the need for bus zone protection is highly felt because, the faults level at busbar is very high and the faults on bus-bar causes discontinuance of power to a large portion of the system.

The owner has blocked you Answer should contain a minimum of 25 characters. Ir relies on the feeder currents in the busbar. Go to the following web site www. Any ideas of your own? This is standard notation that Amps in the primary will produce 5 Amps on the secondary.


Good revision and informative. Professional in AutoCAD programming. Regards, Phil Corso, PE cepsicon aol.

Bus Zone Protection and Causes of Busbar Faults

High impedance and Low impedance types. By Black, Don on 6 May, – From the point of view of zones of protection they are classified into discriminating and check zone protections. The main drawback with this type of differential protection is the difference in the magnetic conditions of the iron cored CTs which may result in false operation of the relay at the time of an buszonf fault.

My Question is New. Danger zone in food processing apply where the chemicalbiochemicalmicrobiological reaction are at h To search the site, enter your search terms in the box labeled “search the site” and hit Enter. If any fault, either a phase to phase fault or phase protextion earth fault occurs in the systems, the sum of these currents will not be zero and some current will flow through the relay and causes the relay to operate and isolate the faulty section.

Help keep our servers running MEP is rising concept in every client organization who dealing with projects fir Two other items are indicated in the diagram. Facebook Linkedin Google Plus Twitter. On many installations busbar zone protection is not considered necessary or its pritection is limited to important substations.

Bus zone protection

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For HV switchgears with more than one bus bars and switching isolators etc, the low impedance differential relay is used which ubszone a costlier solution. The clearing of a busbar faults requires the opening of all the circuit branching from the faulted bus zone or busbar section.


A simple differential protection scheme is shown in busznoe figure below.

To exclude a word, precede it with a “-“, as follows: Unfortunately, the answer you are trying to submit has already been added. In HV switchgear the zone of protection is segregated according to the position of the bus section or bus coupler.

By Mohammad khoshkholgh Dashtaki at Sep Difficulty arises from the fact that there are many pit-falls. It provides stability in case of problems with disconnectors auxiliary contacts stuck contacts or wiring problems.

In such a case duplicate A and B protections cannot be used. Some tips for better search results Protectioon impedance differential protection for the MV Switchgear Bus bar protection use the principle of comparison of currents by paralleling the secondaries of identical both ratio and parameters current transformers to a current operated relay and a stabilizing resistor in series, with a voltage limiting device across the combination.

By samo on 1 August, – Check for similar questions. The desirable features of bus zone protection include the following:. One is the direction of CTs. That is, if any of the incoming supply conductors carry fault-current but none of the outgoing feeders do, then the supplies are tripped.

Last modified: January 19, 2020