Protective Devices

What is the purpose of installing protective devices in circuits?

• To increase the electrical load capacity

• To improve the aesthetic appeal of electrical installations

• To reduce the cost of electrical maintenance

• To provide protection against electric shock and prevent damage from faults

Tags

NGSS.MS-PS2-5

What does an overcurrent refer to according to BS 7671?

• A current that exactly matches the rated value

• A current that stabilizes circuit operations

• A current exceeding the rated value

• A current that is below the rated value

Which device is NOT mentioned as providing protection against earth leakage?

• Circuit breaker

• Voltage regulator

• Residual current device (RCD)

• Fuse

What is the main disadvantage of BS 3036 fuses?

• Simple to check if blown

• Cannot break large fault currents

• High cost to replace fuse element

• No moving parts

What is the fusing factor range for BS 88-3:2010 cartridge fuses?

• 1.25–1.70

• 1.6–1.9

• 1.8–2.0

• 2.0–2.5

Which type of circuit breaker is suitable for transformers and industrial welding equipment?

• Type B

• Type 1

• Type C

• Type D

What is the primary purpose of the plug-mounted fuse in BS 1362 cartridge fuses?

• To protect the appliance itself

• To increase the plug's current rating

• To enhance the plug's durability

• To protect the flexible cord

What are the two means of tripping for circuit breakers according to BS EN 60898?

• Manual trip and Automatic tripping device

• Electrical trip and Mechanical tripping device

• Thermal trip and Magnetic tripping device

• Digital trip and Analog tripping device

What does an RCD compare to detect earth leakage?

• The current flowing out through the line conductor with the current returning through the neutral

• The temperature difference in the circuit

• The resistance between the earth and the neutral conductors

• The voltage difference between line and neutral conductors

What major advantage does an RCBO provide over other protective devices?

• It can detect and amplify current signals

• It allows earth fault protection to be restricted to a single circuit

• It enhances the electrical capacity of the circuit

• It reduces the need for regular maintenance