Fault Finding & diagnosis

Failure to get a reading of polarity using test method one could indicate?

• A low impedance on the circuit protective conductor

• A short circuit

• A break in the line conductor

• An earth fault

Which of the following would cause a loss of supply to an installation

• Incorrect phase sequence on a motor circuit

• Shorth circuit on a shower circuit

• High resistance joint on a light circuit

• Damaged underground supply cable

To maintain accurate readings, an instrument should?

• Have its batteries replaced frequently

• Be checked annually against national standards

• Be checked against similar instruments

• Be checked daily for any wear or tear

Which of the following is the most likely of implications caused from an exposed terminal?

• Electric shock to a person or livestock

• MCB operate

• RCD Operates

• Main Cut off fuse operates

Which is the correct method of disposing of plasterboard on site?

• Sweep in under the floorboards

• Contact an HSE licensed contractor to dispose of it

• Leave it on the floor

• Dispose of it into the designated skip on site

An insulation resistance test is performed on a standard final circuit, what should the instrument be set to measure in?

• MΩ

• KΩ

• mΩ

• Ω

Which device will protect circuits and equipment from transient voltages?

• MCB

• RCBO

• SPD

• Earth cable

If a copper conductor was halved in length, the resistance would?

• Quadruple

• Stay the same

• Double

• Halve

When are GS38 leads required?

• 50V AC and 120V DC

• Voltages not exceeding 1000V AC

• 50V AC and 500V DC

• below 50V

The insulation resistance test voltage for a SELV installation is?

• 500V

• 230V

• 1000V

• 250V