Zdb before dead tests.

[swaley]

Hi guys got my assesment in 3 weeks and want to get my testing spot on. Little confused whether to test Zdb on 2 way CU before dead tests?? Or do I jump straight into continuity? Thanks in advance.

 

[Pete999]

Hi guys got my assesment in 3 weeks and want to get my testing spot on. Little confused whether to test Zdb on 2 way CU before dead tests?? Or do I jump straight into continuity? Thanks in advance.

Test procedures as per BS 7671 would be my choice. Would be interesting to know your reasons for wanting to test Zdb prior to dead testing.

 

[Octopus]

Test procedures as per BS 7671 would be my choice. Would be interesting to know your reasons for wanting to test Zdb prior to dead testing.

I suppose that would depend on whether the OP is using an existing supply or not. Its not clear. I suspect he means dead testing the circuits on the sub DB

 

[Nigel]

Dead tests should always be done first before live tests for safety purposes.

As you are not being inspected on safety, personally I would not worry to much. However if you want to donit by the book then dead tests first.

 

[swaley]

Yes I meant dead tests on sub DB. Still no clearer?? I presume, lock off and start with dead tests

 

[swaley]

Dead tests should always be done first before live tests for safety purposes.

As you are not being inspected on safety, personally I would not worry to much. However if you want to donit by the book then dead tests first.

Thanks I'm constantly over thinking everything. I will just follow OSG in future.

 

[Octopus]

Did you install the submain?

 

[swaley]

Did you install the submain?

Yes. Why you ask?

 

[Octopus]

Yes. Why you ask?

That wasn't clear from the op.

So I would install and test the sub main first, including live tests...

Then move on to the dead and live live tests in the new building.

You need the ze + R1 +R2 of the sub main top check the Zs of the sub main (which is also the zbd)

Then you have the zbd +R1 +R2 and then the Zs ....

So one EIC, 2 schedules ....

Where is the RCD?

 

[westward10]

Technically there is no such thing as Zdb the measurement at your two way CU is Zs. Try to use the correct terminology.

 

[Taylortwocities]

Yes. Why you ask?

Surely you undertook all of the tests (live and dead) on this circuit?
The answer will be on the installation certificate for the submain.

 

[Deleted member 105166]

Technically there is no such thing as Zdb the measurement at your two way CU is Zs.

^^^ This. "Zdb" is not BS7671 terminology.

 

[westward10]

Not to my knowledge, no.

 

[Octopus]

Not to my knowledge, no.

But widely used

 

[westward10]

But widely used

I agree but not a abbreviation I ever quote. I believe it has been adopted where a true value of Ze cannot be established due to operational restrictions and the value is often referred to as Zdb which although often quoted is not a recognised abbreviation.