R1 + R2 on commercial eicr.

[SteveH40]

R1+R2, quick question, if you couldn't locate the corresponding cpc could you just link the line conductor to the cpc/earth bar and test at the furthest point for R1+R2 on a radial circuit?

I know the non-corresponding cpc / neutral would be a C3 but would be nice to get R1+R2 this way instead of just an R2 using the long lead (which i tend to use anyway).

your help much appreciated.

 

[shanky887614]

R1+R2, quick question, if you couldn't locate the corresponding cpc could you just link the line conductor to the cpc/earth bar and test at the furthest point for R1+R2 on a radial circuit?

I know the non-corresponding cpc / neutral would be a C3 but would be nice to get R1+R2 this way instead of just an R2 using the long lead (which i tend to use anyway).

your help much appreciated.

you could r2 to find the right cpc

 

[SteveH40]

true, would involve a lot more dismantling work though, would probably be easier to list as a limitation and requires further investigation, R2 using long lead and C3 the board for non-corresponding cpc/neutrals.

 

[davesparks]

true, would involve a lot more dismantling work though, would probably be easier to list as a limitation and requires further investigation, R2 using long lead and C3 the board for non-corresponding cpc/neutrals.

Limitations are something to be agreed before you start, not a means of making the job easier by avoiding doing it properly.

 

[Farmelectrics]

locate the cpc in db using r2 method

 

[IzzyS]

R1+R2, quick question, if you couldn't locate the corresponding cpc could you just link the line conductor to the cpc/earth bar and test at the furthest point for R1+R2 on a radial circuit?

I know the non-corresponding cpc / neutral would be a C3 but would be nice to get R1+R2 this way instead of just an R2 using the long lead (which i tend to use anyway).

your help much appreciated.

That's what the OSG shows. Unfortunately what they forget to tell you is that any supplementary bonding, metal containment on the circuit under test, or other fortuitous connections to earth may skew your results.

As this is an EICR, all you need to establish is that there is a connection to the MET and that the loop impedance is satisfactory for the correct operation of the protective device.

 

[Deleted member 9648]

Agree with above. On an EICR it would not necessarily be worthwhile carrying out an R1+R2 test. That test is intended for initial verification BEFORE energising a circuit. On an EICR the circuit has already been energised,if Zs test results are as expected then thats good enough. I would only carry out R1+R2 tests on circuits where Zs readings were not what I would expect.

 

[SteveH40]

Thanks all, I know that there is risk attached but how many of you do the live Zs test at the furthest point for all circuits? I know it's what's agreed with the client etc etc but i try to get as close to 100% Zs as is humanly possible (or reasonably practicable as they say!). I then go for L-PE and then L-N insulation resistance followed by R2 long lead or link L-PE at DB and test at furthest point for R1+R2. I mainly go for this as most of the time previous records are flaky at best.

 

[SteveH40]

on a side not, working in an old single phase wylex metalclad board today, neutrals and earths all over the shop along with old cables cut off and left and others just left with tape around......... decided to have a word with the funeral home manager and got permission to turn off the board to make good........ all old crap now removed and neutrals and earths in the correct numbered terminals. Felt good after that can carry on testing it tomorrow now

 

[davesparks]

Why didn't you get permission to turn the board off before you started testing?

 

[SteveH40]

i hadn't started testing at that point, i was doing the inspection precedes testing bit, opened the board to see a rats nest, sought permission, isolated board, made good all issues and testing will now commence tomorrow.......

 

[Deleted member 26818]

Just be sure that the client is aware that cleaning up the rat's nest is a remedial, not part of the inspection and testing.

 

[IzzyS]

Thanks all, I know that there is risk attached but how many of you do the live Zs test at the furthest point for all circuits? I know it's what's agreed with the client etc etc but i try to get as close to 100% Zs as is humanly possible (or reasonably practicable as they say!). I then go for L-PE and then L-N insulation resistance followed by R2 long lead or link L-PE at DB and test at furthest point for R1+R2. I mainly go for this as most of the time previous records are flaky at best.

As you're doing it anyway, I would do the R2, or R1+R2 first - if the cpc is not properly connected at the db (or somewhere else) your loop test will put 230V on any connected exposed- or extraneous-conductive-parts. May be OK if there is no one else about, but you need to consider the risk.

 

[Deleted member 72666]

Thanks all, I know that there is risk attached but how many of you do the live Zs test at the furthest point for all circuits? I know it's what's agreed with the client etc etc but i try to get as close to 100% Zs as is humanly possible (or reasonably practicable as they say!). I then go for L-PE and then L-N insulation resistance followed by R2 long lead or link L-PE at DB and test at furthest point for R1+R2. I mainly go for this as most of the time previous records are flaky at best.

Your testing is completely in the wrong order which could be dangerous and the results could under certain conditions be meaningless!

 

[Richard Burns]

Your testing is completely in the wrong order which could be dangerous and the results could under certain conditions be meaningless!

Remember this is an already energised installation and EICR testing may have a different order for convenience.

 

[SteveH40]

Remember this is an already energised installation and EICR testing may have a different order for convenience.

Exactly Richard, on EICR I tend to vary the test routine dependent on operational constraints. Guidance note 3 also states that you can test in a different order.

 

[IzzyS]

Indeed it does. However, following the "correct order" saves you having to backtrack when you find, for example, that you've performed the IR test lives to earth, but your subsequent R2 wander lead test proves that you don't in fact have a connection to earth, rendering the IR results meaningless.

 

[SteveH40]

Indeed it does. However, following the "correct order" saves you having to backtrack when you find, for example, that you've performed the IR test lives to earth, but your subsequent R2 wander lead test proves that you don't in fact have a connection to earth, rendering the IR results meaningless.

point taken, as an example, testing at a funeral care home this week, lots of metal decorative fittings on the wall, first job of the day while quiet in the place got my R2 long lead out and had a good walk around testing the metalwork of the fittings, couple had no earth traced to bad fly lead on fitting, global IR on the board later and finally Zs all points..... every days a new routine.