1991

1. INTRODUCTION
Qualifications and experience
1.1 My name is Philip Richard Boys. I am a Principal Engineer at Mitton Electronet
Limited (MEL) based in Christchurch.
1.2 I hold the following qualifications:
(a) BE (Electrical, Hons), Canterbury University; and
(b) I am a member of the Institution of Professional Engineers New
Zealand (IPENZ); and
(c) I am a Chartered Professional Engineer (CPEng (Elec)) and registered on the International Professional Engineer’s register
(IntPE(NZ)).
1.3 I have worked in the New Zealand electricity industry since 1995.
1.4 As a Principal Engineer at MEL, I provide consulting services relating to high voltage substation investigations, including conceptual and detailed design and site construction management, lightning protection, earthing systems design and site measurement. One of my specialist activities relates to power system earthing and induction, its modelling and associated site investigations. This includes substations, industrial complexes and transmission line pylons.
1.5
1.6
I have extensive experience in applying the CDEGSTM suite of modelling tools to analyse earthing systems, electric and magnetic fields (EMF), and radio frequency interference (RFI) and audible noise (AN) calculations. I have carried out associated field testing to confirm the accuracy of the modelling.
CDEGS™ software is world renowned in the high voltage power industry and is used by over 500 utilities and consultancies throughout the world. I have developed practical and reliable test procedures and equipment to carry out on site testing of earthing systems.
I have also assisted:
(a) The Electricity Engineers’ Association to prepare the EEA Guide to
Power system earthing practice, June 2009.
Page 2 of 16

1.7
1.8
(b)
(c)
With the preparation of AS/NZS 7000:2010, Overhead line design –
Detailed procedures, section 10.6, Design for earth potential rise
(EEA approach).
With the preparation of AS/NZS 4853:2012, Electrical hazards on metallic pipelines, section 5, Design Process (New Zealand only).
I have tested the earthing systems of almost all of the power stations in New
Zealand, almost all Transpower’s substations in New Zealand, as well as many other substations in New Zealand and Australia.
Some typical projects that I have worked on include:
(a) Design and measurement of the impedance of transmission line support structures, power stations, and substations to determine the adequacy of the earthing in relation to earth potential rise (EPR)
(b) hazards;
Measurement and computer modelling of the earthing of transmission line support structures to determine appropriate modifications necessary to ensure proper lightning protection of transmission lines;
(c)
(d)
Modelling of gas and fuel pipelines located near power lines to determine the levels of induced voltage in the pipelines; and
Modelling and measurement of EMF levels under transmission lines and in substations.
1.9 A review of the electrical safety issues associated with the planned 110 kV transmission line has been undertaken.
1.10 The voltage rise on the planned 110 kV poles has been calculated, where the voltage rise is expected to range from 1,240 V to 2,950 V. This means that without mitigation, there will be touch voltage hazards onto the poles and touch voltage hazards on nearby electrical structures within 2 m of a faulted 110 kV pole. There will be no step voltage hazards around any planned 110 kV poles.
1.11 A risk assessment has been conducted, which concludes the risk of the identified hazards is generally low, except at a few pole locations in a public park area, where significant gatherings may occur. The identified hazards can be mitigated, with the use of earthing conductors around the planned 110 kV poles, and isolation installed in any nearby fences.

1.12 A review of parallel conductive infrastructure has been carried out to determine the induced voltages on the parallel infrastructure. The calculated induced voltages have been calculated to be acceptable on such items as parallel fencing. The induced voltages on parallel Chorus infrastructure has been determined to be safe, although the voltage, on one section, exceeds the limits defined in the Electricity (Safety) Regulations, section 33, but are less than limits given by the ITU, document K68. This voltage is considered to be acceptable, where Chorus have accepted the increased limits for recent, similar projects.
1.13 A review of the EMF, RFI and AN concludes that the maximum values are significantly less than the guideline values and that these are acceptable.
Involvement in project
1.14 My involvement in this project was to conduct studies to review:
(a) Earth Potential Rise (EPR) issues associated with support structures
(poles) for the planned 110 kV transmission line. The investigation determines the hazards and risks to the public, personnel and
(b) equipment that could arise during fault events at the planned 110 kV transmission line poles.
Low Frequency Induction (LFI) issues associated with the planned
110 kV transmission line. The investigation determines the LFI
(c)
(d) induced voltages on parallel infrastructure (i.e. Chorus cables, farm fencing, and water pipes) and risks to personnel and equipment that could arise during maximum normal operating conditions, and fault events along the planned 110 kV transmission line.
The EMF issues (electric and magnetic field levels) associated with the planned 110 kV transmission line and compliance with regulations and guidelines.
The “environmental” issues (Radio Frequency Interference (RFI) and
Audible Noise (AN)) associated with corona produced by the planned
110 kV transmission line and compliance with regulations and guidelines.
1.15 Site visits were not undertaken for this review, where areal imagery along the line route was used. Computer modelling, using CDEGS™ software was used to assist with this study.

1.16 Excluded from the above studies were EPR and LFI issues associated with the following infrastructure, where these issues were reviewed by others in a separate report:
(a) The Kiwirail railway lines and associated infrastructure (i.e. signalling circuits); and
(b) The Vector owned gas pipelines.
1.17 One of the main modelling tools I have used is the CDEGS™ software package). This was developed by a team of engineers from a company called
Safe Engineering Services (SES) in Canada. It is a powerful set of integrated engineering software tools designed to accurately analyse problems involving grounding/earthing, electromagnetic fields, electromagnetic interference including ac/dc interference mitigation studies, and various aspects of cathodic protection and anode bed analysis with a global perspective, starting literally from the ground up. Extensive scientific validation of the software using field tests and comparisons with analytical or published research results have been conducted for over many years. The validation conducted by SES as well as other independent researchers is documented in hundreds of technical papers published in the most reputed international journals.
1.18 I am the author of the document entitled ‘Hangatiki – Te Awamutu 110 kV
Transmission Line EPR, Induction, RFI, AN, EMF Investigation’ that accompanied the notices of requirements and the assessment of environmental effects (AEE) lodged in support of the Project.
Purpose and scope of evidence
1.19 My evidence will address the following matters:
(a)
(b)
The extent and nature of any hazards and associated risk from EPR issues associated with faults along the planned 110 kV transmission line.
The extent and nature of any hazards and risk from LFI induced voltages on parallel infrastructure (i.e. Chorus cables, farm fencing, and water pipes, excluding Kiwirail and Vector infrastructure) associated with the planned 110 kV transmission line.

(c) Compliance with regulations and guidelines for EMF issues, and
“environmental” issues (RFI and AN) associated with corona produced by the planned 110 kV transmission line.
1.20 I have relied on the following sources of information in preparing my evidence:
(a) NZ Electricity (Safety) Regulations 2010, reprint as at
(b)
1 February 2014.
LineTech report LEH11863, Rev 00, March 2014, Te Awamutu
(c)
Reinforcement 110 kV OHL, Railway Low Frequency Induction
Report.
NZECP34:2001, New Zealand Electrical Code of Practice for
Electrical Safe Distances.
(d)
(e)
(f)
(g)
(h)
EEA Guide to Power System Earthing Practice, June 2009.
IEC 60479:2005 Effects of current on human beings and livestock.
AS/NZS 7000:2010, Overhead line design – Detailed procedures.
AS/NZS 4853:2012, Electrical hazards on metallic pipelines.
NZS 6801 (1991, 1999 & 2008), Acoustics - Measurement of environmental sound.
(i) environmental sound. Values given are guideline limits.
(j) NZS
(k)
(l) electromagnetic noise from high voltage a.c. power systems, 0.15 –
1,000 MHz.
The “Electric and magnetic fields and your health, 2013 Edition”
Handbook, issued by the NZ Ministry of Health, 2013.
International Telecommunication Union, ITU-T K.68, (04/2008) Series
K: Protection Against Interference, Management of electromagnetic interference on telecommunication systems due to power systems and operators' responsibilities
Expert Witness Code of Conduct
1.21 I have been provided with a copy of the Code of Conduct for Expert Witnesses contained in the Environment Court’s Consolidated Practice Note [2014]. I have read and agree to comply with that Code as if this matter were before the
Environment Court. This evidence is within my area of expertise, except where
I state that I am relying upon the specified evidence of another person. I have not omitted to consider material facts known to me that might alter or detract from the opinions that I express.

2. SUMMARY OF INVESTIGATIONS UNDERTAKEN
Glossary of Terms
2.1 The following terms and associated abbreviations are referred to within this evidence:
(a) AN: Audible noise generated by the corona discharge surrounding an
(b)
(c) energised conductor
CDEGS™ Current Distribution, Electromagnetic Fields, Grounding and Soil Structure Analysis.
Earth fault: the connection or flashover of one or more conductors to earth.
(d)
(e)
(f)
EMF: Electric and Magnetic Fields.
EPR: Earth Potential Rise.
RFI: Radio Frequency Interference noise generated by the corona discharge surrounding an energised conductor
Impedance: a measure of the total opposition to current flow. (g)
(h)
(i)
(j)
(k)
(l)
(m)
(n)
(o)
Resistance: a measure of the total opposition to current flow.
Steady state: refers to the normal ac operation of the line.
Step voltage – definition from the EEA Guide to power system earthing practice, June 2009 – means the difference in surface potential experienced by a person bridging a distance of one metre with the person’s feet apart, without contacting any other earthed object.
Touch voltage – definition from the EEA Guide to power system earthing practice, June 2009 – means voltage that will appear between any point of hand contact with uninsulated metalwork and any point on the surface of the ground within a horizontal distance of one metre from the vertical projection of the point of contact with the uninsulated metalwork.
A: ampere, unit of current.
Ω : ohm, unit of resistance.
V: volt, unit of voltage.
Note the symbols just mentioned are often expressed with the prefixes m, k and M to denote milli (x10 -3 ), kilo (x10 3 ) and mega (x10 6 ) respectively.

Methodology
2.2 I have described below the methods Mitton Electronet Ltd used to undertake the investigation into EPR, Induction, RFI, AN, EMF effects of the proposed transmission line.
For the EPR review:
(a) Align advised the following information: i) ii) iii)
Line data (conductor types, configuration, span lengths).
Fault levels at the Source Substations (TMU and HTI).
The probable maximum primary and backup fault durations
(0.12 s primary, and 0.35 s backup).
(b) iv) The typical 110 kV pole foundation types planned to be used.
Using the CDEGS™ Right-Of-Way (ROW) module, the maximum pole voltage rise at all poles along the planned 110 kV transmission line was calculated.
(c)
(d)
(e)
The pole voltage rise calculations were conducted with the calculated pole footing resistances of 52 Ω .
The tolerable touch, step and transferred voltage limits have been calculated based on the EEA Guide to Power System Earthing
Practice, June 2009, calculations, which are based on the IEC/TS
60479, 2005, curve C2 tolerable body currents, in compliance with the
Electricity (Safety) Regulations, 2010.
Using the CDEGS™ MALZ module, the touch voltages onto the
(f)
(g)
(h)
(i) poles, step voltages around the poles and the transferred voltage
EPR contours surrounding the poles have been calculated.
These voltages have been used to calculate the hazards at each pole.
A “Dial-before-you-dig” survey was undertaken to determine the infrastructure (i.e. Chorus cable, pipes, etc.) and a desktop review of aerial photos of the line was undertaken to determine:
(i) The types of area the planned line passes through, such as play grounds, parks, campsites, industrial areas, etc.
(ii) The proximity of nearby infrastructure and the parallel sections to the planned 110 kV line.
A high level assessment was undertaken to conduct a first pass review to determine which poles may need a more detailed review.
Where poles are identified as having issues, then mitigation options are proposed to ensure site safety and compliance.

3.
For the Induction review:
(a) The parallel infrastructure, particularly the Chorus cables, were
(b) identified (excluding KiwiRail and Vector gas pipeline infrastructure).
Using the CDEGS™ Right-Of-Way (ROW) module, the maximum induced voltages have been calculated for both normal operating and earth fault conditions.
If hazards are identified, then these areas are highlighted. (c)
For the EMF, RFI, AN review:
Using the CDEGS™ SESEnviroPlus module, the maximum electric field (EF), magnetic field (MF), RFI and AN values have been calculated, for the worst case situation.
SUMMARY OF RESULTS FROM INVESTIGATIONS
3.1 I have described below the results of Mitton Electronet Ltd’s investigation into
EPR, Induction, RFI, AN, EMF effects of the proposed transmission line.
3.2 EPR Issues
(a) The proposed 110 kV pole footing resistances are determined to vary
(b) from 7 Ω to 52 Ω .
In the event of a phase to earth fault at a proposed 110 kV pole, the
(c) voltage rise on the faulted 110 kV pole is calculated to range from
1,240 V to 2,950 V.
The touch voltages on the faulted 110 kV poles are calculated to range from 300 V to 1,780 V.
(d)
(e)
(f)
For most cases the touch voltages on the poles exceeds the touch voltage limit (523 V for Special Locations and 1,240 V for Normal
Locations) and are considered hazardous.
The risk associated with touch voltage hazards onto most of the
110 kV poles is considered to be Low.
The risk associated with touch voltage hazards onto poles P9, P10 and P11 is considered to be Intermediate, since these are located in a public park. The installation of gradient control conductors or asphalt
(g)
(h) around the poles will mitigate the touch voltage hazards.
There are no step voltage hazards. There is no risk associated with step voltages.
Surrounding each pole transferred hazards extend up to 2 m from the
110 kV pole. This means that:

3.3
(i)
(i) There are likely to be transferred touch voltage hazards onto stock fences where a planned 110 kV pole is located within
2 m of the fence. This affects poles P2, P3, P22, P27B,
P32, P33, P34, P39, P42, P43, P45, P50, P51, P52, P54,
P71 (image unclear), P76, P99, P101, P103, P104 (image unclear), P107, P142 (image unclear), P148, P155, P157 and P178.
There are no transferred hazards on nearby water pipelines (ii) or other infrastructure (note that EPR reviews on nearby
Vector gas pipelines and KiwiRail infrastructure is covered in a separate report by others).
Pole P8 is located near existing Chorus infrastructure, however, a detailed review indicates the proposed pole location is acceptable.
There are no transferred hazards onto nearby Chorus infrastructure.
Induction Issues
(a) The maximum induced voltage on telecommunications equipment during steady state conditions is calculated to be 27 V, which is acceptable.
(b) The maximum induced voltage on telecommunications equipment during earth fault conditions is calculated to be 930 V. This exceeds
650 V, which is the allowable level given in the NZ Electricity (Safety)
Regulations 2010, reprint as at 1 February 2014, clause 33 parts
(c)
3,(a),(ii),B and 4,(b), but is less than the ITU K68 equipment damage limit of 1,030 V. This voltage is considered to be acceptable, where
Chorus have accepted the increased limits for recent, similar projects.
The maximum induced voltage on parallel water pipelines during
(d)
(e) acceptable.
The maximum induced voltage on parallel water pipelines during earth fault conditions is calculated to be 306 V, which is acceptable.
The maximum induced voltage on parallel stock fences during steady state conditions is calculated to be 6.8 V/km. The maximum parallel continuous length is 4.4 km. We do not believe that any fence section will be continuous for 4.4 km without any breaks, and therefore consider the inducted voltage on parallel stock fences to be acceptable.

(f) The maximum induced voltage on parallel stock fences during earth fault conditions is calculated to be 125 V/km. The maximum parallel continuous length is 6.8 km. We do not believe that any fence section will be continuous for 6.8 km without any breaks, and therefore consider the inducted voltage on parallel stock fences to be acceptable.
3.4 EMF, RFI, AN
(a) The maximum EF is calculated to be less than 1.7 kV/m, which is less
(b) than the limit of 5 kV/m.
The maximum MF is calculated to be less than 12 μ T, which is less
(c)
(d) than the limit of 200 μ T.
The maximum RFI is calculated to be less than 35 dB(1 μ V/m), which is less than the limit of 45 dB(1 μ V/m).
The maximum AN is calculated to be less than 24 dBA, which is less than the guideline value of 45 dBA.
4. SUMMARY OF KEY RECOMMENDATIONS
4.1 The following key recommendations are made:
(a)
(b)
Mitigation is required at proposed 110 kV poles P9, P10 and P11, where these are located in a park area. This could consist of an earth conductor buried in a ring, about 0.5 m deep, 1 m out from each pole and bonded to the pole foundation reinforcing. This will reduce the touch voltage on to the poles to be lower than the touch voltage limit, thereby eliminating the touch voltage hazard at those poles.
Mitigation is required to be installed in the stock fencing near a number of proposed 110 kV poles. This could consist of simple insulators installed in the stock fencing near the poles.
5. SUBMISSIONS
5.1 I have read all of the submissions received in relation to the Project that raise matters potentially within my area of expertise, and each is commented on in numerical order of the submission number.

5.2
5.3
5.4
5.5
Vector [No. 003]
Vector Gas Limited supports the proposal providing it achieves compliance with “pipeline code requirements and pipeline protection”.
This matter is addressed in the evidence of Mr Edward Hardie.
KiwiRail [No. 31]
KiwiRail is opposed to the Project with potential impacts on its infrastructure cited as one reason.
This matter is addressed in the evidence of Mr Edward Hardie.
B-A Gadd [No. 033]
Safety is one of the reasons this submitter is opposed to the Project, with her concerns being that:
 she will not be able to utilize part of her property,
 the line will (in her opinion) cause a safety issue for residents and workers; and,
 the proximity of the transmission line to the rail infrastructure creates a safety risk.
The safety concerns mentioned in this submission do not appear to directly reference electrical hazards. Notwithstanding, the conclusions regarding the electrical safety from section 2.3 apply. I consider the risk associated with touch voltage hazards around the affected poles to be Low. However, if this is still considered to be unacceptable, then the mitigation described in section 3.1 of my evidence above can be applied. This will then eliminate any electrical hazards.
With regard to property utilisation, as long as legal requirements are met (i.e. the requirements from ECP34), I do not see any reason why any property utilisation would be restricted.
With regard to the structural integrity of the line, and the proximity of the transmission line to the rail infrastructure, this matter is addressed in the evidence of Mr Edward Hardie.
R T Clarke [No. 034]
Safety in the event that the transmission line collapses is one of the reasons this submitter is opposed to the Project

5.6
5.7
5.8
With regard to the structural integrity of the line, this matter is addressed in the evidence of Mr Edward Hardie.
Conductor drop is a rare occurrence. If there is a conductor drop, then I expect the imbalance current caused by one phase being disconnected to cause the protection to trip prior to the conductor landing on the ground (the protection is expected to operate within 0.12 s of phase disconnection). At this stage I have not been advised if an auto-reclose function will be enabled in the protection.
O Shergold [No. 035] and R Lewis [No. 037]
These submitters are opposed to the Project and cite one reason as the safety issues associated with the proximity of the transmission line and poles to their place of work, Otorohanga Timber Company.
The conclusions regarding the electrical safety as I’ve outlined in section 2.3 of my evidence above apply. The risk associated with touch voltage hazards around the affected poles is considered to be Low. However, if this is still considered to be unacceptable, then the mitigation described in section 3.1 of my evidence above can be applied. This will then eliminate any electrical hazards.
L Phillips [No. 036]
Safety is one of the reasons this submitter is opposed to the Project, but she does not specify what particular event or action she is concerned about.
The safety concerns mentioned in this submission do not appear to directly reference electrical hazards. My comment above in relation to submitters 035 and 037 are equally applicable if this submitter is concerned about electrical safety.
Should the submitter be concerned about the structural integrity of the line, this matter is addressed in the evidence of Mr Edward Hardie.
E Gadd [No. 039]
Safety is one of the reasons this submitter is opposed to the Project. She considers the line will cause a safety issue for residence [sic] and workers, but does not specify what particular event or action she is concerned about.
My comment above in relation to submitters Nos. 035 and 037 is equally applicable to this submission.

6. REPORT of COUNCILS’ PLANNER
6.1 The Report of the Councils’ Planner, Section-42A, noted two issues to be addressed:
(a) Section 9.5, item 1, where a small discrepancy of the dimensions of the pole structures is noted when calculating the electric and magnetic fields around the poles.
(b)
The conductor spacing using in the modelling has been checked, and the conductor spacings are as indicated on the Linetech drawings
LEH11863-1, parts 1, 2, 3 and 4. . There are a couple of minor typographical errors shown in Figure 10 of report MEL-R2047, Rev
03, however, these have no effect on the conclusions of the maximum calculated values.
Section 9.12.2, where the induced voltage on the parallel Chorus infrastructure is noted.
The maximum induced voltage on the Chorus cabling, is on the maximum parallel length. As noted, the maximum induced voltage is
930 V. This is greater than the limit given in the Electricity (Safety)
Regulations 2010, regulation 33. However, additional limits are given in the ITU K68 document, where for short durations the equipment and hazard limits are given as greater than 1,030 V for faults with a duration from less than 0.2 s. Therefore, I consider that the induced voltages are acceptable. Additionally, for recent, similar projects,
Chorus have accepted the higher ITU K68 limits, as for fault durations of such a short duration, the regulated limits are extremely conservative.
7.1 I have reviewed the schedule of conditions proposed by WNL in its applications as lodged with the councils. I have also reviewed the designation conditions included in Appendix 1 of the councils’ planner’s report.

8.
7.2 In both cases, I consider changes are required and as outlined below. For simplicity I have only referred to the changes I consider necessary to the conditions suggested by the councils’ planner.
7.3 Proposed Condition 5.1 (Designations) provides for the location of poles to be changed subject to certain limits. Where a pole location is to change I consider compliance with the provisions of NZECP34:2001 with respect to conductive fences needs re-evaluation. I therefore recommend the following additional condition:
5.3(A) Where the position of any pole is changed in accordance with Condition
5.1, compliance with Clause 2.3 of NZECP34:2001 (which relates to the proximity of conductive fences to transmission line support structures) must be assessed and any required mitigation undertaken as per Condition 6.3 below.
7.4 Proposed Condition 6.3 (Designations) refers to the transmission line being designed and constructed in compliance with the Electricity Regulations 1997.
The regulations were revised in 2010 and a corresponding amendment is required. I therefore recommend that Condition 6.3 should read as follows:
6.3 In designing and constructing the transmission line, the Requiring
Authority shall give consideration to third-party conductive structures and services to ensure compliance with:
(a) Regulations 14, 33, 34, 42, 43, and 44 of the Electricity
(b)
(Safety) Regulations 2010 as in force at the date of confirmation of the designation; and,
Clause 2.3.3 and 2.3.4 of NZECP34:2001.
CONCLUSIONS AND RECOMMENDATIONS
8.1
8.2
The voltage rise on the planned 110 kV poles has been calculated, where the voltage rise is expected to range from 1,240 V to 2,950 V. This means that without mitigation, there will be touch voltage hazards onto the poles and touch voltage hazards on nearby electrical structures within 2 m of a faulted 110 kV pole. There will be no step voltage hazards around any planned 110 kV poles.
A risk assessment has been conducted, which concludes the risk of the identified hazards is generally low, except at a few pole locations in a public park area, where significant gatherings may occur. The identified hazards can be mitigated, with the use of earthing conductors around the planned 110 kV poles, and isolation installed in any nearby fences.

8.3
8.4
8.5
I recommend that the mitigation is installed at the identified pole locations.
Where pole locations are shifted, then the installation contractor should review the location of surrounding infrastructure (fences and gates in particular) to determine if mitigation is required at those poles.
With respect to the concerns expressed in submissions, the risk associated with the pole locations could be considered in more detail, and if required mitigation can be installed.
A review of parallel conductive infrastructure has been carried out to determine the induced voltages on the parallel infrastructure. The calculated induced voltages have been calculated to be acceptable on such items as parallel fencing. The induced voltages on parallel Chorus infrastructure has been determined to be safe, although the voltage, on one section, exceeds the limits defined in the Electricity (Safety) Regulations, section 33, but are less than limits given by the ITU, document K68. I consider the induced voltages to be acceptable, where additionally, Chorus have accepted the limits provided in the
ITU K68 document for recent, similar projects.
8.6 A review of the EMF, RFI and AN concludes that the maximum values are significantly less than the guideline values and that these are acceptable.
Philip R Boys
21 November 2014