2330 Level 2: Safe isolation

[Mr Curnow]

1- To start off we first check the tests leads for damage.
2- Next test between Line and Neutral to see if it's live.
3- Turn off the supply, place the warning sign on the lock, lock it.
4- Keep the key in your pocket.
5- Next test [Line-Earth] [Line-Neutral] [Neutral-Earth].
6- Prove that the tester is still working by using the proving unit.

Is this right? Will I pass by doing this?

 

[Deleted member 26818]

First off you should as you say check the leads for damage, but you should then check the tester works, either by using the proving unit or a known live supply. This will verify both the tester and the proving unit.
Then you should check for voltage between all conductors, not just Line and Neutral.
Turn off supply and re-test between all conductors, before placing warning notice and locking off and placing key in pocket. Not much point locking off, if the MCB hasn't isolated the supply.
Re-test tester with proving unit, or known live supply. Again not much point in locking off, if your tester or proving unit has packed up.
Then place warning etc.
If you have to go away from the board for any reason to conduct any tests, such as to prove the item you are working on is isolated, or to find a known live supply then place warning etc. before you go.

 

[Mr Curnow]

First off you should as you say check the leads for damage, but you should then check the tester works, either by using the proving unit or a known live supply. This will verify both the tester and the proving unit.
Then you should check for voltage between all conductors, not just Line and Neutral.
Turn off supply and re-test between all conductors, before placing warning notice and locking off and placing key in pocket. Not much point locking off, if the MCB hasn't isolated the supply.
Re-test tester with proving unit, or known live supply. Again not much point in locking off, if your tester or proving unit has packed up.
Then place warning etc.
If you have to go away from the board for any reason to conduct any tests, such as to prove the item you are working on is isolated, or to find a known live supply then place warning etc. before you go.

I think they want you to lock it off anyway, If I didn't lock it off then I would fail the exam, It's not as same as it would be on site. Exams are over protective, well you have to be with electricity.

 

[Mr Curnow]

Wouldn't checking between all conductors trip it out though, say if you test from line to earth then the MCB will cut the circuit because current is flowing to the main earthing terminal. I think it's called earth fault current.

 

[Deleted member 26818]

It may cause an RCD/RCBO to trip, depending upon which tester you are using.

 

[firemanowl]

This is the procedure I write in any college exams. Hope this helps.

- Check with customer whether it's ok to isolate
- Disconnect all loads
- Locate source of supply and isolate
- Lock off and place warning signs
- Select and test GS38 voltage indicator on proving unit
- Test supply is isolated
- Retest voltage indicator on proving unit
- Start work if all of the above has been followed and installation is proved isolated

 

[mattmoo1974]

-Check which circuit is to be isolated
-Check if it is ok to isolated said circuit
-Lock off label leave yourself safe <<lollys PLACE KEY IN POCKET!!!!!!!!!!!
-test voltage indicator on proving unit or known supply
-test l-n l-cpc n-cpc
-test voltage indicator on proving unit
-Assess if there are any more precautions you could put in place
-Start work