Wiring Rules 2018: Part 2, Section 8
Compliance must be built in from the start and monitored all the way through. Verification cannot be retrofitted.
Verification is all about a question often posed by consultants, builders other customers and inspectors.
Verification, the title of Section 8, certainly isn’t a word that fits well in the “I think she’ll be right” category. It is “the process of establishing the truth, accuracy or validity.
It is all about that question often posed by consultants, builders other customers and inspectors which have been known to send shivers down the spine of less-prepared or under-researched electricians and contractors when asked: “Do you comply?”
This highly important section is all about two issues:
- ensuring that installations meet the requirements set out in AS/NZS3000 and all related Standards; and
- confirming that all measuring, testing, inspecting and setting to work add up to the ‘all clear’.
As all who are successful in the industry will attest, the process begins well before the installation is even started and doesn’t finish until the last device or item of equipment is functioning successfully.
A system that prompts each activity and ensures the recording of all testing, inspections and results in real time should not be discounted. ‘Start right, stay right’ is the only way.
Changes listed in the ‘preface’ include:
- rearrangement of headings to differentiate between requirement types, including headings such as ‘general – application – visual inspections – test requirements – accepted values’;
- relocation from this section of ELV installation testing to section 7; and
- clarification of EFLI and ELV testing and recording at the main switchboard of the date of initial energising of the installation.
Substantial changes from the 2007 edition in Part 2, Section 8, in page order include:
- Inspection requirements under ‘general requirements’ (a) are now (slightly) better defined and changed from ‘as far as practicable’ to ‘in accordance with 8.1.3 and 8.2 far as practicable’.
Notes 1 and 2 are added to advise that additional inspection and testing may be required for specific installations and to draw attention to NZECP for wiring and fittings near conductive installations.
The 2007 edition exception for possible later testing has not been included (but there is still an exception for RCD testing when the installation is not energised).
The remaining previous text dealing with ‘periodic inspection and testing’ has been placed under its own ‘periodic inspection and testing’ sub-heading and the previous note under that (dealing with additional inspections for certain situations) is not included.
These alterations have not materially changed the requirements. (Reference on the omission can be made in the 2007 edition on p330.) (p416)
- Two additional items are under ‘visual inspection’: (e) ‘electrical equipment’ and (vii) dealing with protection against influences including moisture and (viii) suitability for intended voltage, current and frequency.
Two notes have been added under (e): Note 1 dealing with the suitability of RCDs, residual AC current or pulsating DC current, and Note 2 referring to guidance in Appendix Q for DC circuits. (p418-419).
- Notes under ‘testing’, ‘general’, in the 2007 edition are not included. Reference on the omission can be made in the 2007 edition on p333. (p419)
- The new sub-heading ‘test methods’ is created under ‘testing’, ‘general’. It references AS/NZS3017 as setting out common test methods and cautioning that testing must be carried out without putting at risk the operator, others in the vicinity and the test equipment. A note also advises that other test methods are not precluded. The previous reference to AS/NZS3017 is deleted. (p419)
- The sub-heading ‘low voltage’ is slotted in under ‘mandatory tests’, and the opening statement is reworded but not changed in intent. The note regarding repeating a failed test to confirm rectification success is placed under its own heading ‘test failures’ after the ‘low voltage’ and ‘extra-low voltage’ headings, so applying to both. An exception applying to (a) to (f) is added under (f) and Note 3 changed from ‘HV additional testing possibly being required’ to ‘additional tests for isolated supplies’. (p420)
- A paragraph is added under ‘continuity of the earthing system’, ‘general’, with a requirement for testing a PEN sub-main to confirm the correct PEN earth connection at both ends. (p421)
- The new sub-heading ‘method’ is slotted in under ‘insulation resistance’, ‘general’, but the original text (now split under the two headings) is not changed. However, in Note 1 the (i) and (ii) become bullet points and in Note 2 the paragraph has been rewritten to absorb the information in (i) and (ii) into the main text. (p422)
- The arrangement and text under ‘results’ is substantially changed. Three exceptions and four notes are included under (a) and (b) in place of the previous text. The new exceptions and notes clarify the typical resistance values that may be obtained and may be acceptable when adverse results are found. There is now more information, but with little or no material change. (p423)
- Under the heading ‘polarity’, ‘results’, (b) is reworded to clarify that switches or protective devices must not operate in the earthing conductor or a combined PEN conductor. A new (c) is slotted in to clarify that switches or protective devices must not independently operate in the neutral conductor. There is no change to (a) – or to (d) or (e), which were previously (c) and (d). (p424)
- There are substantial changes to ‘verification of earth fault-loop impedance (EFLI)’. The previous ‘socket-outlet circuits not protected by an RCD’ heading is changed to ‘low-voltage socket-outlet circuits’ so it now covers all socket-outlets rather than just the unprotected ones. All the text is changed to reflect the new wider focus.
There are also notes. Notes 1 and 2 explain the need to test and offer additional information, Notes 3-5 advise where the EFLI tests are not (or may not be) required and Note 6 stipulating that the trip-time in circuits not usually requiring testing must still meet the maximum trip times in situations where the voltage drop may exceed requirements. (p425)
- There are further changes under ‘verification of earth fault-loop impedance (EFLI)’. The sub-heading ‘methods’ is slotted in before ‘results’, with the new sub-headings ‘supply available’ and ‘supply not available’ moved here from paragraphs previously under ‘results‘, ‘methods of measurements’.
There are also corresponding changes under ‘results’ to reflect the change in order of the headings. Users are again urged to become acquainted with the change in arrangement to ensure compliance. (p425-426)
- Notes 1-5 are added under table 8.1 ‘maximum values of earth-fault loop impedance’. Note 3 deals with MCB selection; the others are cross-references to additional information. (p427)
- Likewise, Notes 1-5 are added to table 8.2 ‘maximum values of resistance of final sub-circuits’. Some replace the previous Note 1 (a) and (b) and Note 2.
Notes 1 and 2 explain the basis of calculation, Notes 3 and 4 reference table B.1 and Note 5 requires the shortest route length for both EFL and V Drop. (p428)
- The arrangement of text under ‘operation of RCDs’ is changed, with more emphasis on how testing is to be conducted and verified. The previous separate requirements for Australia and NZ are not included. The exception, for testing in Australia only not being required if no supply is available, is included now in a more direct way. Three further notes are added with guidance on suitability, test operation and a way of testing. Users (especially in NZ) are again urged to become acquainted with the change in arrangement to ensure compliance. (p428-429)
- The date of initial certification must now be available on site, as under ‘verification records’. (p429)