Electrical Fault Diagnosis Quiz

What is the most appropriate method to protect against electric shock when carrying out fault diagnosis work?

• Wear rubber gloves

• Use insulated tools

• Ensure the equipment is isolated from the power supply

• Stand on an insulating mat

Why would a method statement be used by an experienced operative before undertaking work on an installation to diagnose a fault?

• To reduce the cost implications of the work to be undertaken

• Ensure effective billing of the work procedure or process

• Ensure Health and Safety requirements are considered

• To monitor customer satisfaction for trade reviews

Which standard must test leads comply with in order to help avoid electric shock when undertaking fault finding and diagnosis work?

• IEC 61010

• IEC 60364

• IEC 60947

• IEC 60204

Which document should be completed when replacing an existing faulty fan isolator switch?

• Electrical Installation Certificate

• Minor Electrical Installation Works Certificate

• Periodic Inspection Report

• Electrical Condition Report

Who would an operative need to keep informed of serious faults found on the lighting circuits in a fully functioning commercial unit?

• The client

• The Health and Safety Executive

• The local council

• The insurance company

A client has reported that a number of space heaters have stopped working following extensive use during a cold spell. Which of the following items would be the most likely to be checked during testing for fault diagnosis purposes?

• Circuit supply voltage and protective device status

• Heater element resistance

• Thermostat operation

• Wiring connections

What is the most likely outcome following a small leakage between neutral and earth due to water ingress in the connections of a luminaire?

• High earth fault currents causing the main DNO fuse to operate

• Phase sequencing becoming reversed causing machinery faults

• High short circuit currents causing circuit fuses to operate

• Residual current flow to earth causing the operation of an RCD

What is the most likely reason for the sound of arcing within a contactor, controlling heaters, each time the load is on and running?

• Loose connections

• Overloaded circuit

• Faulty contactor

• Incorrect voltage supply

Where is a short circuit in a cable most likely to be located?

• At the terminations

• In the middle of the cable run

• Near bends or kinks in the cable

• At the junction boxes

What fault would an experienced operative suspect if the final socket-outlet on a radial circuit was not operating but the rest of the outlets on the circuit were?

• Open circuit at the final socket-outlet on the circuit

• Short circuit at the final socket-outlet on the circuit

• Faulty socket-outlet

• Incorrect wiring