In TT earthing system, all exposed-conductive-parts of the installation/loads must be connected to a common earth electrode. The neutral point of the source
system is connected to earthed at a point outside of the influence area via earth electrode. So, the impedance of the earth fault consists mainly two earth electrodes (i.e. the source and installation electrodes) in series, so that the magnitude of the earth fault current is generally too small to operate overcurrent relays or fuses, and the use of a residual current operated device is essential as a first level isolation.
In this system RCD will disconnect the circuit, if there is a leakage current. By detecting small leakage currents, they may prevent electrocution as essential part of the automatic disconnection of supply i.e. to switch off when a fault develops in the circuit, rather than rely on human intervention.
In Ecostruxure power design we have option to select earthing system with RCD enabled features for upstream and downstream.
system is connected to earthed at a point outside of the influence area via earth electrode. So, the impedance of the earth fault consists mainly two earth electrodes (i.e. the source and installation electrodes) in series, so that the magnitude of the earth fault current is generally too small to operate overcurrent relays or fuses, and the use of a residual current operated device is essential as a first level isolation.
In this system RCD will disconnect the circuit, if there is a leakage current. By detecting small leakage currents, they may prevent electrocution as essential part of the automatic disconnection of supply i.e. to switch off when a fault develops in the circuit, rather than rely on human intervention.
In Ecostruxure power design we have option to select earthing system with RCD enabled features for upstream and downstream.
Released for:Schneider Electric India
