New Zealand Committee for the Co-ordination of Power and Telecommunication Systems (NZCCPTS)

Tools

The following tools are available.

Disclaimer
The information contained in the worksheets below has been compiled by the NZCCPTS for the use of its members from sources believed to be reliable, but neither the NZCCPTS nor any of the contributors to these worksheets (whether or not employed by NZCCPTS) undertake any responsibility for any mis-statement of information or mistake in the worksheets, and readers should rely on their own judgement or, if in doubt, seek expert advice on the application of the worksheets to work being carried out.


Calculation Worksheets

Worksheets are attached for calculating in Power Company Distribution Networks:

  1. the EPR on distribution transformer earthing systems, HV conductive poles and urban MEN systems, and
  2. the earth impedances of typical Urban MEN systems.

These worksheets correspond to worked examples used in the AS/NZS Handbook HB 219 ‘Earth potential rise – Protection of telecommunications users, personnel and plant – Worked examples for the application guide’.

EPR Calculation Worksheets

Earthing System EPR
is Calculated for
HV voltage HV supply NER at HV source Typical of which country HB 219 Worked Example No. Download PDF
file
Download Mathcad
file
Download
Excel
file
Rural distribution transformer 11 kV Overhead None NZ 3.2.1

22 kV Overhead None Australia 3.2.2

HV concrete pole 11 kV Overhead None NZ & Australia 3.3.1
11 kV Overhead 4 ohms Australia 3.3.2
22 kV Overhead 8 ohms Australia 3.3.3
33 kV Overhead None NZ & Australia 3.4.1
33 kV Overhead 20 ohms NZ & Australia 3.4.2
Isolated 48 customer urban MEN system 11 kV Overhead None NZ 3.5.1
Extensive interconnected urban MEN system 11 kV Overhead None NZ 3.6.1
11 kV Overhead 20 ohms Australia 3.6.2
22 kV Overhead None Australia 3.6.3
22 kV Overhead 8 ohms Australia 3.6.4
11 kV Buried None NZ 3.7.1

Urban MEN Impedance Calculation Worksheets

Type of URBAN MEN network

 

Poles conductive and bonded to LV MEN Typical of which country  MEN impedance value used in HB 219 Worked Example Nos.  HB 219
Worked
Example
No.
Download PDF
file
Download Mathcad file Download
Excel
file
Extensive interconnected MEN None NZ 3.6.1
3.7.1
4.1.1
All Australia 3.6.2
3.6.3
3.6.4
4.1.2
Isolated, 48 customer MEN None  NZ 3.5.1  4.2.1

Mathcad Worksheets Version Number

The above Mathcad worksheets can be read using Mathcad version 10 (also known as Mathcad version 2001 or 2001i) or a later version of Mathcad.

To obtain a copy of Mathcad, or to get advice if you are having problems using Mathcad, contact your local Mathcad distributor. Details of your local distributor can be obtained from http://www.ptc.com/products/mathcad/.

The New Zealand Mathcad distributor is:

Hoare Research Software Ltd
PO Box 4153
Hamilton East
New Zealand
Ph: 0800 477 776
Fax:  07 839 9103
Email:      info@hrs.co.nz
Web: http://www.hrs.co.nz/mathcad