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Switchgear protection

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    Switchgear protection has been around for as long as we have had switchgears. The idea of the protection is that when we have an overcurrent or overvoltage, a relay will notice it and react. The relay opens the breaker to avoid damage to the equipment. If the breaker is unable to break the circuit, then the feeders to that switchgear have to break the main breaker. That is how the infrastructure is established with switchgear protection. To get the relays to work properly different trip times for the relays were made. These have been calculated so that the correct relay trips at the right time.

    The protection relays are mounted in the top compartment in the switchgear cabinet. Inside they are installed so they can disconnect the breaker, but never connect the breaker. Other modules that are installed in the top compartment are used for measuring the power going in and out of the switchgear cabinet.

     

    Reference: 

    1. http://www.abb.fi (referred 05.12.2011)
    2. Power Technology Wasa Pilot Power Plant

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