All the Data, All the Time
Not only can N2P Controls offer Electrical/Electronic automation design assistance, but can help with process engineering design, therefore, offering a fully package solution. This package solution helps give our clients a competitive edge.

Client: Taupo District Council
Turangi Water Treatment Plant Upgrade

  • Unitronics PLC & HMI
  • Telemetry

 Download this case study as a PDF (2.4MB)


Turangi is located on the southern end of Lake Taupo. The region around Turangi is known for being The Trout Fishing Capital of the World. It also boasts excellent hunting, mounting biking, tramping, white water rafting, skiing, and sightseeing. Despite being surrounding by some of the cleanest water in the world, the 3,500 people of Turangi did not have a water treatment supply that met with the New Zealand Drinking Water Standards 2005 (rev. 2008).


Turangi’s existing water treatment plant was built in the 1950s, and consisted of taking water from a natural spring, dosing with chlorine and hydrofluorosilicic acid (HFA) before pumping it to a reservoir. To meet the revised New Zealand Drinking Water Standards (NZDWS) the plant needed a significant upgrade.

Taupo District Council put out a tender for the upgrade of the Turangi Water Treatment Plant. With N2P Controls’ resident Process Engineer, Niki Johnstone, assisting Hynds Environmental Systems Limited (HESL) won this contract.


The upgrade included UV treatment, chlorine dosing, hypochlorite dosing and provision for future filtration. The tender asked for the plant to be fully automated with a telemetry link back to Taupo District Council’s Service Centre, to allow remote monitoring and control, and the water reservoir, which is located 500m away from the treatment plant. The plant required a HMI at the plant to allow for local monitoring and control.

N2P Controls won the contract to supply the automation and telemetry link for HESL. N2P Controls’ Niki Johnstone worked with all parties involved with this project including HESL, Harrison Grierson (HESL’s Process Engineer) and Taupo District Council to provide the Functional Description for the new treatment plant. Once authorised, N2P Controls, sourced, programmed and installed the PLC and HMI into the new Motor Control Cabinet. N2P Controls also interfaced with the telemetry system supplied by QTech.

N2P Controls’ own Design Engineer, Peter Taylor, wrote the PLC program and was on site to assist in commissioning. His electronic, electrical and programming background, coupled with his extensive industry experience, makes Peter an ideal partner to have on site to quickly overcome any commissioning hurdles.

The Technical Stuff

The PLC and HMI used was a Vision 130 from Unitronics (an Israeli based PLC manufacturer). The PLC used its propriety communication protocol to communicate with the HMI, and used Modbus TC/IP to communicate with the QTech telemetry unit. The PLC had 25 digital I/O points, 10 analogue I/O points and over 50 Modus addresses that interfaces with the telemetry unit. The PLC was housed within the main MCC cabinet with the VSDs mounted separately.


With N2P Controls being able to supply the automation design, supply and commissioning assistance as a package solution, it reduced the number of contractors Hynds Environmental had to work with, and allowed Hynds Environmental to focus on deliverying a successful project for their client. John Bradford, Construction Manager at Hynds Environmental, “Says the experience and product knowledge of N2P Controls’ staff ensured that we could entrust them with automation of this project and freed us up to focus on the installation of this project.”

N2P Controls prides itself on offering a total package solution with engineering assistance from a Chartered Process Engineer, design and build of the MCC cabinet, PLC procurement and programming and on site commissioning assistance.

Let N2P Controls help make your next project a success.

 Download this case study as a PDF (2.4MB)