Earth Continuity Testing & Fault Finding

Which of the following tests would be carried out 'live':

• insulation resistance

• earth continuity

• prospective fault current

• ring circuit continuity

Which of the following requirements from GS 38 applies to test equipment which requires more than one test lead?

• The leads must be at least 1m in length

• The leads must have a c.s.a. of at least 1.5 mm2

• The leads must be colour coded for identification

• The leads must be permanently attached to the instrument

The test probes on leads used with electrical test equipment must be insulated and with exposed metal tips not exceeding?

• 2mm

• 3mm

• 4mm

• Only spring loaded retractable screened probes to be used

What is the wire size for Main earthing conductor ?

• 10mm2

• 6mm2

• 16mm2

• 2.5mm2

A continuity test as part of fault diagnosis would be carried out with which instrument:

• Earth-fault loop impedance tester

• High resistance ohmmeter

• Low resistance ohmmeter

• RCD Tester

On inspection of terminations at a motor, you observe conductor insulation has melted and discolouring of the terminal metal the most likely cause would be:

• Overcurrent

• Loose connection

• Open circuit

• Short Circuit

An RCD would protect against the following fault:

• Open circuit

• Overcurrent

• Short circuit between live conductors

• Short circuit between live conductors and earth

What is the wire size for Equipotential bonding?

• 10mm2

• 16mm2

• 4mm2

• 6mm2

All electrical testing equipment should comply with which document?

• The Electricity at work Regulations

• BS7671

• GS 38

• Part P

A result of >100Ω on a continuity test would indicate what type of fault:

• None

• An insulation Failure

• Open Circuit

• Short Circuit