Types Of Faults

What is a short circuit?

• A condition where a circuit is overloaded with too many devices.

• A condition in an electrical circuit where the electrical current flows through an unintended, shorter pathway.

• A condition where the circuit is not complete due to a break.

• A condition where the resistance in a circuit is higher than expected.

What causes an earth fault current?

• Too many loads connected to a circuit.

• Unintentional connection between a live conductor and an exposed conductive part.

• A nail through two live conductors.

• Cross connections between conductors at outlets.

Which device is often combined with a circuit breaker to become an RCBO?

• Fuse

• RCD

• Continuity tester

• Insulation resistance tester

How can a short circuit be located?

• Visual check at outlets on circuit.

• Using a low-Ohm continuity tester.

• By checking the ratings of protective devices.

• Using a high-Ohm continuity tester.

What is the cause of an overload?

• A nail through two live conductors.

• A low resistance connection.

• Incorrect settings for a motor.

• A break in the circuit.

What is an open circuit?

• A circuit with a high-resistance connection.

• A circuit with too many devices connected.

• An electrical circuit that is not complete.

• A circuit where the current flows through an unintended pathway.

What causes high resistance joint/connection?

• Cross connected line and neutral.

• Too many loads on the circuit.

• A complete circuit without breaks.

• Deteriorated termination.

How to locate crossed polarity?

• Using an insulation resistance tester.

• Checking the overload settings on motors.

• Visual check at outlets on circuit or in consumer unit.

• Using a high-Ohm continuity tester.

What to look for when locating an overload?

• Incorrect rating or type of protective device.

• Devices turned off that should usually be on.

• High resistance readings from your test using low-Ohm resistance tester.

• Resistance readings between live conductors.

What is the correct way to confirm conductors are incorrectly connected?

• Check for excessive load on circuits.

• Continuity test using low-Ohm continuity tester.

• Incorrect results for continuity test.

• Visual inspection for mechanical damage.