Testing.. Never goes right..

[TPES]

Practicing again...

TN-CS Supply New Built Home

Tested ring final circuit..

P - 0.34
N - 0.34
CPC - 0.59
________________________________________________

N1 - P2 = 0.70

N1 - P2
P1 - N2 = 0.16

P - N Sockets..
1- 0.19
2- 0.16
3- 0.17
4- 0.17
5- 0.18
6- 0.16
7- 0.21
8-
9- 0.18
________________________________________________

P1 - CPC2 = 0.95

CPC1 - P2
P1 - CPC2 = 0.21

P-CPC...
1- 0.23
2- 0.22
3- 0.26
4- 0.22
5- 0.23
6- 0.30 ? Why the high readings on socket 6/7/9..?? really annoys me.. No test i do ever goes right.
7- 0.36 ?
8-
9- 0.30
________________________________________________

Socket "8" was not accessible.. What do you do about this.. What would you write about this on Cert?
________________________________________________

Ze = 0.21
PFC = 1.23 kA
________________________________________________

IR Test..

L-N >1000
L-E >1000
N -E >1000
________________________________________________

Does all look ok ???​

 

[scotsparky]

Hi Mate any of those sockets spurs??

 

[TPES]

Hi Mate any of those sockets spurs??

No none spurs.. all on the ring.

 

[scotsparky]

Are 6,7,9, the furthest away pints sometimes you can get variation but i would think if variation were over 0.05ohms

 

[Spudnik]

Looks ok to me.

Its usually the case that the higher readings are normally spurs.

Should have similar readings wherever on the RFC.

How come socket 8 was not accessible?

Still, a note on the cert wont hurt.

 

[sparkswillfly]

make sur youve got your out going line to incoming neutral and viser verser

 

[Tokyo Joe]

Your to keen!!!!!! If you have not wired it .... it's not your problem !!!!!!
Are ELI readings at each socket within limits ?
With it being new build !!!! These readings don't matter....If the Rcd trip times are within range at each outlet....... if you read the contradicting ECA guide to the Regs

 

[Guest123]

Just because a circuit has RCD protection it does not negate the need for max permitted Zs values to be met.

There seems to be a bit of a culture brewing that if theres an RCD on the circuit then forget about the Zs, not the case in my book.

 

[Spudnik]

Agreed Len,

RCD's should ONLY be used if max disconnections times cannot be met, not instead of.

Obviously except in the case of TT's.

 

[TPES]

I know i am very keen, and this is sad i suppose but lately all i can think about is testing.. and all the tests and results.

This is why its frustrating me when im getting readdings off like this..
would you all be investigating these slightly higher readings on sockets 6/7/9 or just put down your R1+R2 as 0.36 being the highest. (even though the readings are out the 0.05 limit between sockets)

 

[sparkswillfly]

are you using a plug in tester ,if so use the probes were the cables terminate the sockets as the tightness of the plug can varrie from socket to socket

 

[TPES]

are you using a plug in tester ,if so use the probes were the cables terminate the sockets as the tightness of the plug can varrie from socket to socket

So you suggest to take the socket off and test with the probes on terminations not the (R1+R2) socket tester?

 

[Spudnik]

Ideally yes, because sometimes contacts in the sockets wear etc and can give odd readings.

Shoving the plug in and out a few times may help.

Would be interesting to see your results with the 3 wire method.

 

[Tokyo Joe]

Obviously all your tins of beans are all facing the right way !

 

[Mr Mark Sparks]

sid
you will find as you do more testing that the readings often vary a little from what you would expect its a case of learning what is an acceptable difference not every circ will be spot on by the book

 

[TPES]

sid
you will find as you do more testing that the readings often vary a little from what you would expect its a case of learning what is an acceptable difference not every circ will be spot on by the book

Ok, I had done a test today on a ring main in a farm house.

I had readings between sockets from 0.28 to 0.36, this is obviously out of the allowed 0.05. Theres no spurs.

Would you say this is acceptable although its not "by the book" and happily record down your r1+r2 as 0.36 ?

 

[scotsparky]

Magic the 0.05 ohms figure is a rule of thumb i use before hunting its not in the book!!. As spread of figures is only 0.08 ohms of a difference then i would recon its ok. However its only going by figues you have given.
There are meny reasond for this spread of reading such worn contaacts if your usin a plug to take loops, Diffrences in connections if you are using probes.
As Jason,Mark has already said its experiance that will tell you these things and if you should go hunting. Thing to take into account are age,usage ect if its 6 year old building getting its first periodic i would say its fine no worries but if its a 50 year old building showing sighns of wear have a think. It could be corrosion in terminals have a GOOD hunt. On older buildings be carefull!!

 

[Mr Mark Sparks]

i agree with scotsparky dont waste time on such a small thing youll find your own level in time in the mean while feel free to ask

 

[TPES]

Cheers for your replys.. appreciate it..

Also i cant find max Ze for different earthing arangements in the red book.. anyone point me in the right direction?

 

[Spudnik]

TNCS - 0.35
TNS - 0.8
TT - 1667 although 200 is acceptable but it could be unstable and so should ideally be under 100.

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