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Got a job where im having to do the usual testing.
I have never tested a set up where due to the tails needing to being so long to reach the consumer unit there has been a switched fuse, this is i believe a standard directive from the DNO the tails then terminate into swa and run from the communal meter cupboard in the corridor and then above fire proof ceiling tiles to the actual flat through the wall into the CU.
Set up is DNO head > meter > isolator > switched fuse switch > into SWA> run via ceiling cavity in hall way> enters CU in flat.
There is a separate earth cable from the DNO service head that doesn't terminate until it reaches the CU in the flat.
I have come across them but never done the testing myself when a switched fuse has been present.
When doing the Ze test normally you disconnect main earth from the supply and measure between line and disconnected earth to get Ze.
Given the presence on the fused switch, will it affect the results or testing procedure? As when comparing it to the typical max values from western power it kind of helps to know if what you got is a correctly obtained test result.
I have looked at guidance note 3 but not found a clear answer.
Should i test for Ze between the meter and fused switch out in the communal cupboard rather than the normal test at the consumer unit?. I will almost certainly have to use a wander lead to go from the flat to the cupboard to connect to earth.
It is just a case of where should i connect to line for the Ze test?
My view is if we really are testing at the origin then it would be best to test before the switched fuse.
any thoughts or advice?
I have never tested a set up where due to the tails needing to being so long to reach the consumer unit there has been a switched fuse, this is i believe a standard directive from the DNO the tails then terminate into swa and run from the communal meter cupboard in the corridor and then above fire proof ceiling tiles to the actual flat through the wall into the CU.
Set up is DNO head > meter > isolator > switched fuse switch > into SWA> run via ceiling cavity in hall way> enters CU in flat.
There is a separate earth cable from the DNO service head that doesn't terminate until it reaches the CU in the flat.
I have come across them but never done the testing myself when a switched fuse has been present.
When doing the Ze test normally you disconnect main earth from the supply and measure between line and disconnected earth to get Ze.
Given the presence on the fused switch, will it affect the results or testing procedure? As when comparing it to the typical max values from western power it kind of helps to know if what you got is a correctly obtained test result.
I have looked at guidance note 3 but not found a clear answer.
Should i test for Ze between the meter and fused switch out in the communal cupboard rather than the normal test at the consumer unit?. I will almost certainly have to use a wander lead to go from the flat to the cupboard to connect to earth.
It is just a case of where should i connect to line for the Ze test?
My view is if we really are testing at the origin then it would be best to test before the switched fuse.
any thoughts or advice?