ZS

[dayrider3883]

can zs readings be taken without cheacking r1+r2 on periodic testing

 

[malcolmsanford]

yes ........................................

 

[a1guvner]

Wash your mouth out, scandelous talk

 

[Plonker 3]

The sequence of testing is for safety reason, so I would say not as you need to verify the earth path you are testing is back to the earth of the DB being tested

 

[malcolmsanford]

I'm assuming with the OP asking Zs he actually means R1 + R2 and not r1 +r2 and on a EICR why do you need to do R1 + R2 readings to get a Zs

 

[needasparks]

You can put as little or as much information down as you like, As long as the reasons why are included. This must be accepted by the client which is why page 1 includes this information but why would you want to not do half the testing.

 

[malcolmsanford]

There could be quite a lot of reasons you can not take an R1 + R2 reading on a EICR

Unable to isolate a circuit in a commercial/ industrial environment
Hi Bay lighting circuit
Safety Services

They spring to mind in a few seconds. So again there is no reason you need to do a R1 + R2 test on an EICR to record a Zs value

 

[a1guvner]

There could be quite a lot of reasons you can not take an R1 + R2 reading on a EICR

Unable to isolate a circuit in a commercial/ industrial environment
Hi Bay lighting circuit
Safety Services

They spring to mind in a few seconds. So again there is no reason you need to do a R1 + R2 test on an EICR to record a Zs value

Totally see where your coming from but if site conditions dictate you cant obtain R1 + R2 then you would have to clarify you cant obtain your Zs

 

[stonejenson]

Surely if you can measure Ze at board (or obtain by enquiry), but as you say for some reason can't turn off to do dead testing, you can still measure your Zs at the outlets which you do live anyway.
Then, assuming that's good, (R1 + R2) = Zs - Ze.
If you're allowed to put one figure down obtained 'by calculation' why not another? As long as you state that.

 

[a1guvner]

Surely if you can measure Ze at board (or obtain by enquiry), but as you say for some reason can't turn off to do dead testing, you can still measure your Zs at the outlets which you do live anyway.
Then, assuming that's good, (R1 + R2) = Zs - Ze.
If you're allowed to put one figure down obtained 'by calculation' why not another? As long as you state that.

Sounds right, but in GN3 they state you cant rework that figure with that calc, would be to easy but with all the paralel paths as it is a live circuit with bonds in place

 

[stonejenson]

Good point. Hey, I'm still learning (lev-3) but I don't suppose you ever stop do you?

 

[a1guvner]

Definately, as is said often, everyday is a school day,

 

[i=p/u]

parallel paths are good , dont knock them:gunsmilie:

 

[Deleted member 9648]

If you have a previous PIR or cert available when carrying out a EICR,and that cert gives R1+R2 and Zs readings,there really is no need to carry out further R1+R2 tests,which can be time consuming and disruptive. If your Zs test results are identical or at least close to the results on the previous cert,it is reasonable to assume the R1+R2 readings will be the same as well......obviously this approach should be explained on the new cert.

 

[Deleted member 26818]

What exactly does knowing the value of R1+ R2 achieve?
There's no requirement in the Regulations, to measure or record it.
A Zs test is quite enough.