Zdb ok but no R1 + R2

[Amp David]

But if he,s getting a Zdb reading he could be getting yhis through parrell paths of the bonding. When in actual fact he's got no earth. :thumbdown:

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Yeah I know that

 

[SPARTYKUS]

Hi All i know its late friday, but try and help me out with this one if you can.
Just got in now from work on the way home a landlord called me to ask if i could test a communal DB he has at an HMO.
I decided to have a look on the way home, long story short each flat was feed from this DB including the communal circuits(lights,sockets).
so i checked Zdb to each flat which was ok but when i did R1+R2 test on the supply cable to each flat i got nothing,tried to each flat and 4 out of the 5 came back with a zero reading.
Distribution board was contactum,each flat was feed from a 40 amp b type mcb (No RCD on DB).

Any thoughts as its got me wondering, the Zdb to each flat was ok but R1+R2 no reading at all.

Alright Delboy

Interesting thread btw.

Having re-read your opening post, I can only surmise that R2 for the sub main is broken for 4 of the 5 flats. As others have pointed out you may very well still get a cracking Zdb via parallel paths (spesh if Bonding in place for water service in each flat for example and this runs via pipework back to DB1 - the origin board so-to-speak).

So Mr R2 test will reveal all. Hopefully.

 

[Hawk81]

Why is everyone missing the obvious here? I find it hard to believe that 4 out of 5 flats have a broken R2 in the supply cable

 

[i=p/u]

open switch isolater... i know

 

[Amp David]

Can't be that simple?

OP is going to be aware of any switch isolators as he'd have to be closing then to get his Zdb

 

[keniff]

Hawk 81 bang on with this, mcb's are open and there for no line to flat, link out from breaker output to earth bar on each individually

 

[SPARTYKUS]

Don't mean to deflate anyone, but it's hard to say really without actually being there !

Let us know Delboy

 

[keniff]

Don't mean to deflate anyone, but it's hard to say really without actually being there !

Let us know Delboy

As always!! Never know what your gonna find on any job....

 

[VMan]

Are you sure the circuits are labeled correctly???

i.e you linked r1+r2 at DB circuit labeled flat1, testing at flat 1 but the r1+r2 circuit is actually flat 4?

 

[SPARTYKUS]

Are you sure the circuits are labeled correctly???

i.e you linked r1+r2 at DB circuit labeled flat1, testing at flat 1 but the r1+r2 circuit is actually flat 4?

Ohhhh thats good, didnt think of that. Nice one

 

[Hawk81]

Are you sure the circuits are labeled correctly???

i.e you linked r1+r2 at DB circuit labeled flat1, testing at flat 1 but the r1+r2 circuit is actually flat 4?

Thats a good suggestion. More like the type of thinking I was talking about

 

[fuzzydunlop]

Call it intuition but, I have a feeling Delboy will never return to the thread

 

[SPARTYKUS]

He will!

 

[VMan]

He will!

he didn't

 

[Farmelectrics]

why did he do his live tests before his dead tests

 

[needasparks]

Perhaps it needs another shilling in the meter or he found his mojo....

 

[Delboy10]

I have returned to the thread chaps sorry about the long time away,I should have updated this ages ago apologies all round.
Right long story short went back a few days later, long wandering extension lead in hand, found out it was exactly what VMAN suggested the D.B was incorrectly labelled apart from flat 5, so when I thought I was doing r1+r2 on flat 1 it was actually flat 3 as labelled on the board.
thanks to everyone who posted for your help and suggestions
nice on lads
(don't worry in future I will report back straight away)