L3 Electrical - Earthing, Safety & Testing

An electrical intake system which uses an earth rod would be classed as

• TT

• TN-S

• TN-C-S

• PME

An electrical intake system whereby the main earth conductor is connected to the sheath of the incoming supply cable is known as

• TT

• TN-S

• TN-C-S

• NC-S

The earthing system whereby the neutral combines the function of both neutral and earth is termed

• TN-S

• TT-S

• TN-C-S

• NE-S

The size of the main earthing conductor would typically be

• 6mm²

• 10mm²

• 12mm²

• 16mm²

The size of the main bonding conductor would typically be

• 4mm²

• 6mm²

• 10mm²

• 16mm²

Which one of the following tests should be carried out on the earthing circuit with the circuit live?

• Earth Loop Impedance

• Insulation Resistance

• Earth Continuity

• Polarity Test

A test current of 150mA should cause a 30mA RCD to trip out in which of the times listed below?

• 0.4 seconds

• 40 milliseconds

• 4 seconds

• 4 milliseconds

The main use of a 30mA RCD is to provide which of following?

• Additional protection

• Protection against overloading

• A test point for instruments

• Protection against older wiring

The permanent inscribed notice on an earth bonding clip must read

• safety electrical connection

• safety electrical connection, do not remove

• do not remove

• safety electrical connection, replace after removal

Which one of the following supply systems would have three live conductors and a neutral?

• 4 phase

• 3 phase

• 2 phase

• Single phase