3. Safe Isolation

Question 1

Why do we need electrical isolation?

Answer 1

Its vital for safety.
The consequence of failing to undertake electrical safe isolation can be dangerous and life changing.

Question 2

Equipment requirements for safe isolation:

Answer 2

1. A voltage indicator complying with GS38
2. A compatible proving unit.
3. A lock and or multi lock system.
4. A warning notice which identifies the work being carried out.
5. Relevant PPE.

Question 3

Step by step safe isolation procedure.

Answer 3

1. Obtain required permission to work on the installation.
2. Identify sources of supply.
3. Test voltage indication to ensure it functions correctly.
4. Isolate the supply, disconnecting the system from mains.
5. Secure/lock off the isolation using the lock.
6. Use voltage indicator to determine that the system is dead.
7. Prove the voltage indicators functionality.
8. Put up a clear visible warning sign to indicate that plant has been isolated.
9. Once confirmed dead, work can begin.

Question 4

How to test for dead on a single phase system:

Answer 4

• Line and Neutral
• Line and Earth
• Neutral and Earth.

Question 5

How to test for dead on a 3 phase system

Answer 5

10 POINT TEST:

L1 and L2
L1 and L3
L1 and Neutral
L1 and Earth

L2 and L3
L2 and Neutral
L2 and Earth

L3 and Neutral
L3 and Earth
Neutral and Earth

Question 6

EAWR states that no work on or near live conductors should be carried out unless:

Answer 6

• It is unreasonable in all circumstances for it to be dead; and
• It is reasonable in all circumstances for them to be at work on or near it while its live; and
• Suitable precautions are taken to prevent injury.

All three of these conditions must be met in order to work on or near live conductors.