Correct steps for Ze test on block of flats

[lau05225]

If I were to conduct a Ze test for the stairway lighting of a block of flats would this be the correct sequence of events:
1)turn off each breaker
2)turn off main isolator and lock off
3)remove main earthing terminal
4)put croc clip on main earthing terminal with one lead of tester
5)use other lead of tester to go across each incoming phase and record highest reading

 

[malcolmsanford]

Near enough, you will though have to make sure that in step 1 your not turning off anything that will affect someone in the the flats. If the board also did say the fire alarms or emergency lighting you will have to inform the residents that the comunial lights and any other service will be off. Also you will need to make sure that by disconnecting the earthing conductor to this board it is not going to leave any still energised boards/circuits without an earth.

Step 5 is slightly wrong also. Yes you will croc clip the earth conductor and then with the other probe you will probe the LINE conductor. There is no need to test the NEUTRAL for the Ze test

 

[yellowvanman]

When you say remove main earthing terminal (MET) you mean remove main earth conductor from MET don't you? You then remove any potential parallel paths to earth eg. bonding.

All else is correct.

 

[morph]

not for ZE,

Near enough, you will though have to make sure that in step 1 your not turning off anything that will affect someone in the the flats. If the board also did say the fire alarms or emergency lighting you will have to inform the residents that the comunial lights and any other service will be off. Also you will need to make sure that by disconnecting the earthing conductor to this board it is not going to leave any still energised boards/circuits without an earth.

Step 5 is slightly wrong also. Yes you will croc clip the earth conductor and then with the other probe you will probe the LINE conductor and that will give you PEFC. You should then un croc the earth and then test between LINE and NEUTRAL to get you PSCC, and which ever is the higher you take.

 

[Sintra]

Step 5 is slightly wrong also. Yes you will croc clip the earth conductor and then with the other probe you will probe the LINE conductor and that will give you PEFC. You should then un croc the earth and then test between LINE and NEUTRAL to get you PSCC, and which ever is the higher you take.

Just a pointer that the main earthing conductor needs to be reconnected to carry out the PFC.

 

[malcolmsanford]

not for ZE,




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Thanks Morph I did get onto the PSCC test ......thank s for pointing that out its been a long week lol

 

[Goody]

If I were to conduct a Ze test for the stairway lighting of a block of flats would this be the correct sequence of events:
1)turn off each breaker
2)turn off main isolator and lock off
3)remove main earthing terminal
4)put croc clip on main earthing terminal with one lead of tester
5)use other lead of tester to go across each incoming phase and record highest reading

Check this out -> YouTube - External earth loop impedance test (Ze).

 

[morph]

Thanks Morph I did get onto the PSCC test ......thank s for pointing that out its been a long week lol

i always liken this sort of thing to making a cup of tea, we can all do it but try writting down the instructions and will forget to put water in the kettle !
actually i do it when making it too LOL