2365 203 #21 - Safe Isolation

What is the main reason for carrying out safe isolation?

• To save energy

• To test RCDs

• To prevent electric shock during work

• To increase voltage

Which regulation requires the use of safe isolation procedures?

• Part P

• Electricity at Work Regulations 1989

• BS7671 Regulation 411.3

• Part F

What is the first step of safe isolation?

• Test for voltage

• Lock off the supply

• Identify the source of supply

• Fit the warning label

What must be done after isolating a circuit and before working on it?

• Fit an RCBO

• Notify the customer

• Prove dead using an approved voltage tester

• Replace the MCB

What tool is used to prove a circuit is dead?

• Socket tester

• RCD tester

• Two-pole voltage tester

• Continuity meter

What should be used to confirm the voltage tester is working?

• Multimeter

• Proving unit

• Plug-in lamp

• Loop tester

What is the correct order of proving dead?

• Test the tester → test the circuit → retest the tester

• Isolate → test the circuit

• Lock off → prove live

• Notify → test → report

What should be used to prevent someone from accidentally switching the circuit back on?

• RCD

• Danger tape

• Lock-off device

• Warning sign only

What is a lock-off device?

• A fuse

• A special plug

• A physical device that prevents switch operation

• A data label

What should accompany a lock-off device to warn others?

• Earth clamp

• Handwritten note

• Warning label/tag

• Cable tie