Zs tests on radial circuits?

[nadger]

Just taken delivery of my very own NICEIC DVD: "inspection and testing - initial verification for domestic properties" and after watching it i have a question.

In the chapter about testing for Zs on radial circuits, the NIC bod says that testing on exposed live parts is a direct contavention of the Electricity at work act section 14, there for the NIC require only a calculated Zs entering on their EIC's using Zs = Ze + (R1+R2)

is this correct? because i'd have thought testing live installations would fall within the boundaries of a "competent person"

 

[Deleted member 9648]

NIC policy is not to Zs test at luminaires for safety reasons.....suits me....balancing on a pair of steps trying to get the flaming leads onto a tiny connector block and just as the test starts the poxy earth croc clip drops off.....then on the 15th attempt you manage to keep them connected for long enough for the test to start only for the effing type B mcb to drop out.....i'ts an overated pastime.

 

[Des 56]

Ah the good old Nic again

In all fairness they are probably following Ewr regulations closely
There is no need to work live if it can be avoided

In the case of initial verification, it is considered unnecessary and its safer to calculate from dead tests than work live

 

[Spudnik]

I mentioned this on my last assessment and he told me there is no reason not to do a live Zs on a radial lighting circuit.

 

[nadger]

humm, bet Kewtech arnt happy then, after developing their extremely overpriced light fitting test thingys!!

 

[Des 56]

He is not speaking with fluent Nic speak then

On a Pir it would more than likely be un avoidable,but their policy I believe is different to the guy doing the assessment

 

[Des 56]

humm, bet Kewtech arnt happy then, after developing their extremely overpriced light fitting test thingys!!

You mean the adaptors for testing R1 + R2

 

[nadger]

i havnt really looked at them to be honest, a mate bought some and moaned like mad at the cost and said dont bother if we were thinking of buying them

 

[nadger]

He is not speaking with fluent Nic speak then

On a Pir it would more than likely be un avoidable,but their policy I believe is different to the guy doing the assessment

so when my local assesor asks me to perform a Zs on a radial and i state Tony Cable says i shouldn't do it, will i fail

 

[Spudnik]

Yep......

 

[Des 56]

Re visit fee as well

 

[Guest123]

I'm afraid regardless of all the red tape and bureacracy and he said, she said, I do and will continue to test Zs with my trusty meter.

 

[Des 56]

Yeah I have the same attitude
The litigation culture may have reared its ugly head
They may need to give this advise,but personally, they probably dont agree with a lot of the nonesense they have to preach

 

[Guest123]

The way I see it I am my own health and safety officer and everything I do, I do taking into account all risks associated with the procedure. Plus I think I'm big enough to make up my own mind now. My mother hasn't cleaned my face with a licky tissue for years.

 

[RexT]

Hi guys,

It is always interesting how this works out.

I thought you were allowed to use calculation, so if you added R1+ R2 to Ze it would be Zs. So I guess if you used the R1 + R2 measurements (dead test) and added them to the Ze (live test) then it would give the Zs. I know there is a live test but it would only be one (or at least a couple of verified goes) compared to lts of Zs tests at the final circuits.
I have watched the videos by Tony Cable and like them a lot. He is very competent, straight forward and has a down to earth view which is great.

I believe for the 2391 exam they expect demonstration of testing, measurement and knowledge of the circuits. Of course it goes without saying that safety must be shown at all times so I would agree with compliance with the Electricity at Works Regs 1989 comments, however they primarily use Guidance Note 3 as the reference document, so I believe that this should be your first port of call and follow that.

Good luck

Rex