3003 LO4 12 RCDs Voltage Current & Equipment Class Measurement

What symbol would represent the class of this appliance?

• 1

• 2

• 3

What symbol would represent the class of this appliance? (Charger for a razor)

• 1

• 2

• 3

What symbol would represent the class of this appliance?

• 1

• 2

• 3

What would I read if I placed the leads in parallel with a light bulb on a 230 volt circuit?

• Nothing, configuration incorrect causing damage

• 230 Volts AC

• 230 Volts DC

• The load of the light bulb

Answer explanation

The leads are incorrectly inserted causing a short across the supply from phase to neutral

What would I read if I placed the leads in parallel with a light bulb on a 230 volt circuit?

• Nothing, configuration incorrect causing damage

• 230 Volts AC

• 230 Volts DC

• The load of the light bulb

What would I read if I placed the leads in parallel with a light bulb on a 230 volt circuit, but swapped the red and black lead with each other, on the meter?

• Nothing, configuration incorrect causing damage

• 230 Volts AC

• 230 Volts DC

• Negative 230 Volts AC

What would I read if I placed the leads in parallel with a light bulb on a 230 volt AC circuit?

• 230V DC

• 230V AC

• 0V DC as there is only AC on the circuit

• Nothing, won't work

Answer explanation

The leads would short out the supply between phase and neutral causing damage

This is internal circuitry of an RCD, which is connected to a light bulb of about 100 Ohms. If the resistor is added (On the secondary side) for testing the RCD, would it trip if the resistor was 33K Ohms?

• The RCD imbalanced detection current is too small

• Yes

• No. There is no imbalance between the phase and neutral

• The resistor should have higher Resistance, over 100K Ohms, and then it would trip

• The resistor value should be less than about 3.3 K Ohms, then it would trip.

This is internal circuitry of an RCD, which is connected to a light bulb of about 100 Ohms. If a resistor is added (On the supply side) for testing, would the RCD trip if it was 33K Ohms?

• The RCD imbalanced detection current is too small

• Yes

• No. There is no imbalance between the phase and neutral

• The resistor should have higher Resistance, over 100K Ohms, and then it would trip

• The resistor value should be less than about 3.3 K Ohms, then it would trip.

This is internal circuitry of an RCD, which is connected to a light bulb of about 100 Ohms. If a resistor is added for testing (connected around coil), would the RCD trip if it was 33K Ohms?

• The RCD imbalanced detection current is too small

• Yes

• No. There is no imbalance between the phase and neutral

• The resistor should have higher Resistance, over 100K Ohms, and then it would trip

• The resistor value should be less than about 7.6 K Ohms, then it would trip.

Answer explanation

There is an imbalance between phase and neutral, as some residual (Small amount) of current leaking from phase to neutral, but in this case, not enough to trip the RCD