High ZE Reading in Flat

[jengo22]

I have been asked to carry out a rewire of a top floor flat when checking the existing supply characteristics.
TN-S with a ZE of 1.24 ohms and PFC of 1.91 KA. 1361 Type 2 with 100 amp Fuse

Should I contact the DNO and ask for them to come and check before commencing work.
Unable to treat as TT and run earth cable down the back of the building, will be using a Wylex dual RCD board for all circuits.
If I complete a certificate all my Zs reading will be really high.

 

[Amp David]

hahaha :wink5: cheered me up normally called something else

As it was a light hearted post i didn't want to insult you by calling you anything to awful :wink5:

 

[jengo22]

contatced DNO they are comming out on Wednesday this week to check all the flats are due for an upgrade.
See what they say let you know thanks for all input.

 

[Amp David]

Have you nulled your leads resistance before testing?

Which test is this then?

 

[GLENNSPARK]

Which test is this then?

yep...lol...

 

[ipf]

Just a POINT with the Ze. Looks like you're getting the right figures, not necessarily in the right order.

 

[Engineer54]

............

 

[Engineer54]

contatced DNO they are comming out on Wednesday this week to check all the flats are due for an upgrade.
See what they say let you know thanks for all input.

I hope you did conduct your Ze test etc at the incoming mains position and not at the flat's CU, or your going to look a right Charlie when the DNO come out to check!!! lol!!

​

 

[Amp David]

E54, bet your right there, doing his Ze in the flat, quality! Poor fella, bet his head is going round in circles.

 

[malcolmsanford]

Just a POINT with the Ze. Looks like you're getting the right figures, not necessarily in the right order.

As Andre Previn turned up now?

 

[bartkusal]

I have been asked to carry out a rewire of a top floor flat when checking the existing supply characteristics.
TN-S with a ZE of 1.24 ohms and PFC of 1.91 KA. 1361 Type 2 with 100 amp Fuse

Should I contact the DNO and ask for them to come and check before commencing work.
Unable to treat as TT and run earth cable down the back of the building, will be using a Wylex dual RCD board for all circuits.
If I complete a certificate all my Zs reading will be really high.

You sure that Ze is not 0.1204 ohm, if your PFC is1910 A, then Ze=230V/1910A=0.1204 ohms, not 1.24 ohms as you say.

 

[Plonker 3]

PFC is calculated with parallel paths connected, Ze is measured with them disconnected. So unless you take a Zdb with all parallel earth paths connected your method of working it out is incorrect.

 

[ipf]

As Andre Previn turned up now?

Well spotted Malc, I knew someone would.
I still think that when Eric was on about 'notes' he was on about payment.lol.

When you look at it, though, 0.124 would't be far out, eh ? Just noticed, caught on post after your's. Someone's got the point.

 

[Amp David]

contatced DNO they are comming out on Wednesday this week to check all the flats are due for an upgrade.
See what they say let you know thanks for all input.

What did they find juengo my old chum?