High R1 + R2 Readings

[kduck]

Hi,

Just taken these readings on a ring final

R1+R2

at the sockets

1 0.67
2 0.67
3 0.70
4 0.71
5 0.70
6 0.70
7 0.81 Spur
8 0.67
9 0.75
10 0.77
11 0.91 spur
12 0.71


Ze = 0.26 and Zs = 0.57

so all ready the sockets on R1+ R2 are all more than Zs any ideas
Insulation test L / N 77
E / L 84
E/ N 81

Also taken cooker reading, one 10mm wire running 9m, R1+ R2= 1.25 Zs = 0.75

meter was tested this week
help

 

[old dog]

there seems to be a problem with your meter 10mm at 9meters R1+R2 by calculation 0.05796
call it 0.06 for cash
osg table 10 mm at 10 meters 0.06

 

[DanBrown]

They seem a bit off. Have you zeroed the leads?

 

[KNIPEX]

have you subtracted you leads reading from this measurment??

 

[Guest123]

Snap!!!!!

 

[Spudnik]

+1 here

 

[harvey]

what are the sockets wired in if 2.5 twin and cpc under the floor if so they are high readings, have you followed the test procedure ie: end to end first that way you should find out if you have problem with one or more of the wires

Harvey

 

[kduck]

took the readings end to end, also zero the leads. The house is a large one and all the sockets where on the same circuit up and downstairs plus the garage. So to get the readings down the easy option was to put the kitchen on it own ring, now R1 + R2 max is 0.07 in the kitchen and 0.10 on the socket circuit.

 

[harvey]

That was it all the sockets on one cct also probably over a 100m of cable hence high if you break them down even more 1st floor on one and ground on another is that possible ?

 

[Plan]

Isn't the max length on a 32a ring wired in 2.5/1.5 t&e cable 100m due to the cable resistance and volt drop?

 

[Stedger]

I think 100m ring length is right in for the 16th. I don't have my book handy but i think it is now 92m in the 17th edition. Not certain but pretty sure.
My rule of thumb is never use anywhere near a full roll of cable for a circuit.

 

[old dog]

thats 100 square meters floor area being served .
appendix 15