Testing question

[m top]

hi all I am currently working as a mate the contractor I'm working for which I shall not name does the following test.
he only measures zs doesn't do continuity r1 r2 he says that there is a good earth return if these results are within those permitted, he takes his ze from his zs to obtain his r1 r2 value,,now I am not saying I am right but shouldn't you prove a earth path exist before you power up to comply with ados ? The only reason I can see he does this is to save time but I'm guessing he is cutting corners views please or is this permitted.

 

[telectrix]

you're correct. he's either lazy or incompetent (or both).

 

[Andy78]

Cutting corners. But don't correct the man too vigorously if you value your job

 

[Paultrim123321]

Is this for an EIC or EICR?

 

[varilite]

Yes this makes a difference as when doing EICR installation already is powered

 

[Badged01]

I have heard of this being used by the "£60 EICR" gang --- dont do the full checks but get your (R1 + R2) from (Zs - Ze). Saves time and gets the whole job done in 4 hours!!

 

[Dizzy_Maskell]

Like all things in life unfortunately sometimes we can't carry out 100% of tests to the regs for various reasons if time and money no object. However these things need to be arranged as part of the limitations and agreements set out with the client when the job is arranged.
It's easy to slag people of but there is a difference between knowing what to do and having set parameters with a client


Personally I always advise testing to the guide lines but can't always get some one to agree the full cost of that so calculate R1, R2 for example.
EICR only though more thorough tests must be done on initials

 

[ChrisElectrical88]

Never to be done on an initial verification. I have done it before on a EICR on minor works (tin hat on) but rarely. I normally do my R2s on EICRs or even R1+R2. +. Ze.

 

[Risteard]

It is perfectly acceptable to use a Zs test as a means of verifying cpc continuity on a periodic inspection, however you cannot deduce an R1+R2 value from this so I would expect to see that as a limitation (unless an R2 wander lead test had been done instead).

 

[GLENNSPARK]

christ we hear some drivvel around here dont we...
to this half arsed chancer of a boss who thinks its appropriate to just energise without confirming its safe to do so then further more allows those who he is supposed to be influencing to witness such activities:

either do it rite or jack it in!!

and to them that were bleatin on about (R1 R2)...and not being able to carry out this test under certain conditions:

ever heard of a wander lead & method 2?

sinking feeling....

 

[SirKit Breaker]

If it is Initial Verification, then he cant do this, its a big NO NO. All dead tests must be carried out properly, and in the correct sequence, before doing live testing. This is to highlight problems that may cause a danger when the install is energised. New installations cannot be energised and certificates cannot be issued if there are faults on Initial Verification, they must be corrected first, and then appropriate testing redone to confirm compliance, there are no execeptions.

On a Periodic, things are a bit different, and you can pretty much do what you like in any order that you choose. Not good practice but unfortunately it is acceptable. What he has done is not strictly wrong, but if he did things properly and methodically, then faults will be a lot easier to identify and deal with, and his report and results would be of more help the next time it needed testing.

Cheers.............Howard

 

[Deleted member 9648]

R1+R2 essential for initial verification of a new install.

R1+R2 not essential for an EICR. Good practice generally but time and disruption constraints may overide. Probably not even worthwhile where a previous (reliable) EIC or EICR is available,if Zs measurement matches previously recorded results it's reasonable to assume R1+R2 will not have changed from the previously measured value.

Quote from post #11 "On a Periodic, things are a bit different, and you can pretty much do what you like in any order that you choose. Not good practice but unfortunately it is acceptable".


Cant agree with the word 'unfortunately'.....in the circumstances I have described, where a previous reliable cert showing R1+R2 values is available on an EICR, IMO an R1+R2 test is overkill and a waste of time and effort unless the measured Zs differs from the previously recorded result.

 

[Dizzy_Maskell]

christ we hear some drivvel around here dont we...
to this half arsed chancer of a boss who thinks its appropriate to just energise without confirming its safe to do so then further more allows those who he is supposed to be influencing to witness such activities:

either do it rite or jack it in!!

and to them that were bleatin on about (R1 R2)...and not being able to carry out this test under certain conditions:

ever heard of a wander lead & method 2?

sinking feeling....

On initial verification I can't agree more but if you are looking at a hotel or other area in which lots of members of the public are walking about. try using your
wandering lead then to do an EICR you cause so many trip hazards and to do it out of hours is not allowed by client request what do you suppose to do then.
Not picking a fight just putting examples out there

 

[Regs]

If it is Initial Verification, then he cant do this, its a big NO NO. All dead tests must be carried out properly, and in the correct sequence, before doing live testing. This is to highlight problems that may cause a danger when the install is energised. New installations cannot be energised and certificates cannot be issued if there are faults on Initial Verification, they must be corrected first, and then appropriate testing redone to confirm compliance, there are no execeptions.

On a Periodic, things are a bit different, and you can pretty much do what you like in any order that you choose. Not good practice but unfortunately it is acceptable. What he has done is not strictly wrong, but if he did things properly and methodically, then faults will be a lot easier to identify and deal with, and his report and results would be of more help the next time it needed testing.

Cheers.............Howard

This raises the question that i asked but was misunderstood
So if you change a consumer unit do you still need to do initial verification first?. This is a little bit of a grey area as its an EIC form to be filled in, so required, but technically your working to an EICR way of testing as its already been energised

 

[Deleted member 9648]

This raises the question that i asked but was misunderstood
So if you change a consumer unit do you still need to do initial verification first?. This is a little bit of a grey area as its an EIC form to be filled in, so required, but technically your working to an EICR way of testing as its already been energised

The initial verification would be to the equipment you have installed.....ie the CU and associated gear,such as the RCD's......not the existing outgoing circuits.
IMO essential tests on existing unaltered final circuits would not include R1+R2. IR tests and Zs would be essential because of the changed characteristics of the new protective devices.
R1+R2 tests would be advised but not essential and could be noted as a limitation on the EIC if not carried out.

 

[Regs]

The initial verification would be to the equipment you have installed.....ie the CU and associated gear,such as the RCD's......not the existing outgoing circuits.
IMO essential tests on existing unaltered final circuits would not include R1+R2. IR tests and Zs would be essential because of the changed characteristics of the new protective devices.
R1+R2 tests would be advised but not essential and could be noted as a limitation on the EIC if not carried out.

Thank you, perfect answer.
I was not asking to get out of doing an R1+R2 as i was previously accused, anyway:

You say changed characteristics i get the Zs part as you could be going from bs3036 rewireable to 60898's so different Zs's. Where does the IR come in please?

If you don't do R1+R2 then how would you confirm polarity? When polarity is mentioned is it just reverse Neutral and live being referd to or any cables incorrectly wired?

 

[telectrix]

polarity faults can be a L-N reversal or a N-E reversal. if the latter, everything works fine till you fit a RCD.

 

[Regs]

polarity faults can be a L-N reversal or a N-E reversal. if the latter, everything works fine till you fit a RCD.

You have not mentioned L-E also, but then reading above i assume you mean everything.

 

[jeffelectric]

i have been working for a firm a month now , they haven't tested any circuits before commissioning , didn't even test an earth rod, i guess 20 years of experience lets them know testing is a waste of time.

 

[Regs]

hi all I am currently working as a mate the contractor I'm working for which I shall not name does the following test.
he only measures zs doesn't do continuity r1 r2 he says that there is a good earth return if these results are within those permitted, he takes his ze from his zs to obtain his r1 r2 value,,now I am not saying I am right but shouldn't you prove a earth path exist before you power up to comply with ados ? The only reason I can see he does this is to save time but I'm guessing he is cutting corners views please or is this permitted.

Look at it this way, when you pass your driving test you get taught to drive at 30 MPH on back streets, in reality how often does this happen? testing is the same. Thats not to say i'm encouraging cutting corners!