Earth Fault Loop Paths and Impedance

What does impedance refer to in electrical installations?

• The total opposition to current flow

• The total current flow in a circuit

• The power consumed by a circuit

• The voltage across a circuit

What components make up the total impedance of a circuit?

• Resistance and capacitance

• Inductance and resistance

• Capacitance and inductance

• Voltage and current

What opposes the current flowing through copper cables?

• Inductance

• Voltage

• Resistance

• Capacitance

What does the inductive part of a transformer winding do?

• Increases voltage

• Opposes the current flow

• Decreases resistance

• Increases current flow

What is the abbreviation for impedance?

• L

• Zs

• R

• I

What is the path followed by fault current in an earth fault loop impedance?

• From the phase conductor to the neutral

• From the phase conductor to earth

• From the earth to the neutral

• From the neutral to the phase conductor

What affects the size of the fault current?

• The value of the combined resistances/inductance within the earth fault loop

• The inductance of the circuit

• The voltage of the circuit

• The capacitance of the circuit

Why is it important to have a low value of impedance in electrical installations?

• To increase the resistance

• To ensure the correct amount of fault current flows back to the protective device

• To decrease the power consumption

• To increase the voltage

What does the earth fault loop include?

• The capacitance of the circuit

• The resistance of the conductors and the sheath in the loop plus the inductive effect of the transformer windings

• Only the inductive effect of the transformer windings

• Only the resistance of the conductors

Why is earth fault loop path and impedance important in electrical installations?

• To increase the current flow

• To ensure the protective device operates as quickly as possible in the event of a fault

• To increase the efficiency of the circuit

• To decrease the overall cost of the installation