ze- no, zs- yes ??

[bobby101]

hi all as the title suggest i was at a second floor flat, doing a pir when i did the ze test the machine i was using the metrel mi3125 gave a buzzing noise to suggest that there was voltage present on the main incomer earth, but the meter did not show a voltage is this a meter at fault or is it somthing that iam missing .. ohh yeah after this was done i reconnected the main earth and tried todo a zs test on a ring circuit and i got a result no probs ( btw, i had done three pirs before this one in the same building and got no probs) also what do i mark down on my pir for this do i have to calculate ka and just note this down in the cert i am at a unsure what to do so any help will be greatly appreciated

 

[Octopus]

Poor connections?

 

[SPARTYKUS]

Not quite sure what you're saying but I can see it possible to get a Zs reading when theres no Ze. parallel paths

Best example is a house near Redditch, TT, Ze 17.8 Ohms.

Do a Zs at a socket under the DB, 0.47 Ohms.

Turns out the water mains is connected to a house over the field (the water board tried to meter them but decided it would cost to much to split it), and guess what earthing that house has, thats right, TNCS. And theres a main bond to the water service :disguise:

 

[bobby101]

so what do i insert in the report

 

[Richard Burns]

If a Metrel is showing a voltage to earth then this is often down to a static charge on the user, if you press the test button through an insulator then the test should work. Try covering half the button with sellotape and only press that bit if there is a problem (the rest of the time it takes the earth from the user). or just press the button with your insulated screwdriver.