(i)Thebasicdesignparametersforthecircuitare:

I

b>

I

gwhere

I

bisthedesigncurrentandIgistheratedoutputcurrentoftheEcogen

I

n>

I

bwhereInisthenominalcurrentoftheoverloadprotectivedevice

DisconnectionofthefinalcircuitintheeventofanearthfaultonthecircuitanddeenergisingoftheEcogenshouldbothoccurwithinanoverallmaximumtimeof

0.4sforTNsystemsand0.2sforTTsystems.However,iftheprotectivedeviceforautomaticdisconnectionincaseofanearthfaultdisconnectslineandneutral

conductors,itisnotnecessarytotakeaccountofthetimetakenfortheEcogentodeenergise.

(ii)WhereanEcogenisconnectedonthesamesideofanRCDasfinalcircuitsprotectedbythatRCD,theRCDmustdisconnectthelineandneutralconductors.

(iii)TheEcogenmustbeprovidedwithmeansofisolationandofswitchingoffformechanicalmaintenance.

16.ConnectionofaEcogentoanexistingfinalcircuit

(i)Thebasicdesignparametersforthecircuitare:

I

z>

I

n+

I

gwhere

I

zisthecurrentcarryingcapacityoftheconductorsofthefinalcircuit,Inisthenominalcurrentoftheoverloadprotectivedeviceand

I

gistherated

outputcurrentoftheEcogen.Thismayrequiretheprotectivedevicetobereplacedwithonehavingalowernominalcurrentrating.

DisconnectionofthefinalcircuitintheeventofanearthfaultonthecircuitanddeenergisingoftheEcogenshouldbothoccurwithinanoverallmaximumtimeof

0.4sforTNsystemsand0.2sforTTsystems.However,iftheprotectivedeviceforautomaticdisconnectionincaseofanearthfaultdisconnectslineandneutral