Ze Testing
- Thread starter ml1936
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When testing Ze you should remove the main earthing conductor and connect the earth lead to that. The main earth is then reconnected for PFC testing.
Remember to switch the main swicth off for the installation before doing this test.
Remember to switch the main swicth off for the installation before doing this test.
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No.
The purpose of a Ze test is to make sure there is an earth to the installation, and that it is below the maximum acceptable readings.
You must have all extraneous metal work disconnected when you carry out this test, otherwise you may get what appers to be an acceptable reading, when in reality there is no main earth connection to the property, and you are reading through the extraneous metal work.
The Ze test should be carried out on the main incomming earth with nothing else at all attatched to it.
The purpose of a Ze test is to make sure there is an earth to the installation, and that it is below the maximum acceptable readings.
You must have all extraneous metal work disconnected when you carry out this test, otherwise you may get what appers to be an acceptable reading, when in reality there is no main earth connection to the property, and you are reading through the extraneous metal work.
The Ze test should be carried out on the main incomming earth with nothing else at all attatched to it.
You disconnect the main earth (the wire from the cutout / cable sheath) from everything and test the wire.
You can leave it in the MET and disconnect everything else from it if you wish, which ever is easiest.
You can leave it in the MET and disconnect everything else from it if you wish, which ever is easiest.
I think i've mis read the original post and assumed all bonding and the main earthing conductor were connected in the consumer unit.
The main protective bonding can be left in place as long as you remove the main earthing conductor in normal circumstances. If the protective boding conductors are connected at the MET and not at the consumer unit then you will have to remove them.
As RF states this is important to ensure you have an earth provided by the DNO.
i've tested many jobs where there is no earth provided by the DNO and the bonding has provided good readings. This is a no no. It normally turns out to be the CNE link in the cut out missing.
The main protective bonding can be left in place as long as you remove the main earthing conductor in normal circumstances. If the protective boding conductors are connected at the MET and not at the consumer unit then you will have to remove them.
As RF states this is important to ensure you have an earth provided by the DNO.
i've tested many jobs where there is no earth provided by the DNO and the bonding has provided good readings. This is a no no. It normally turns out to be the CNE link in the cut out missing.
Yep, I've had exactly the same my self enough times.
It's usually a rotted joint on the PILC round here, although have seen it happen on a split con supply too.
It's usually a rotted joint on the PILC round here, although have seen it happen on a split con supply too.
You test to purely the incomming earth.
If you have an MET with earth from service head, bonding, earth to CU, then you would disconnect the earth from the service head at the MET and test to this in isolation from everything else.
If you have an MET with earth from service head, bonding, earth to CU, then you would disconnect the earth from the service head at the MET and test to this in isolation from everything else.
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