Long lead R2 test

[DeanoRN]

Hi just a quick question if doing long lead r2 test would touching a pin on a socket prove that it’s earthed for example? And if it did would it be accurate? Also on the eicr forms I seen it says you have to put a value for either r1+r2 or simply R2, I know you do the long lead R2 test for gas and water but is it acceptable to do it for others too?
Thanks

 

[gazdkw82]

You can use method 1 or method 2 to confirm R2

Using something that is earthed does not confirm the presence of R2, it just confirms a path to earth.

However, it's worth noting containment can be used as a cpc. You need to be sure what it is your connecting to and what it is your trying to confirm.

 

[Ian1981]

The R1+R2 or R2 columns are found on the EIC, Minor works certificate and a condition report. It should be appreciated that the R2 test alone does not confirm polarity unless you have physically removed the accessories to access the connections and you will have to directly measure the Zs rather than doing the calculated Zs method, if that’s your preference to obtain Zs that is?

 

[DeanoRN]

Thanks for the replies, so I was reading the regs and it said about if there is a fixed lug then the pin will earth the back box so I thought that then it’s possible to get a R2 reading from a pin, but was wondering how accurate it would be compared to getting a reading directly from the earth taking the socket off etc.

 

[Ian1981]

If this is for doing an EICR then that’s one way to confirm that an earth is present at an accessory without dismantling it but for the purpose of writing it in the R2 column as a measured result,then all parallel paths would be required to be disconnected and it’s better to test at the connection itself but it is not something that’s necessary on an EICR, a earth fault loop impedance test would be the required method.
All other methods are not precluded of course

 

[telectrix]

, i wander lead test on the screw heads of each accessory just to confirm presence of earthing. do an accurate R2 at the last point (mid point on a RFC). bugger with dry line boxes though.

 

[DeanoRN]

, i wander lead test on the screw heads of each accessory just to confirm presence of earthing. do an accurate R2 at the last point (mid point on a RFC). bugger with dry line boxes though.

Thanks for the reply, is there much difference in the reading if you test the screw head the testing the actually earth itself?

 

[telectrix]

very little as long as the screws make good conract . not guaranteed to be accurate though. it's a handy method of mapping out a circuit though, due to the fact that R2 will increase from point to point, the further along you get from the CU.

 

[baldelectrician]

Using an r2 will confirm earth continuity, measuring r1r2 a the highest r2 point will confirm polarity