Power management: the story of Otago University


Power management: the story of Otago University

A classic success story using power analysers and meters continues at The University of Otago in Dunedin.

Rising energy prices present an ongoing challenge to energy managers to keep on top of building utilities’ running expenses. The first step in overcoming the energy cost escalation in building and facility management is to record all energy data including electrical power and its quality parameters.

Modern energy meters and power analysers ensure the required transparency in the consumption of building power supply. Electric energy reduction concepts can then be developed and firm measures and actions can be introduced. Detailed data provided by power analysers also enable the ongoing monitoring and logging of the savings and consumption improvements.

Hans Pietsch, energy manager at the Property Services Division of the University of Otago, took the initiative of replacing existing power meters and some other measuring instruments with the Janitza® UMG604 DIN rail-mounted power analyser and UMG96 RM panel-mounted slave meters to measure and analyse the power consumption in some campus buildings.

The project’s aim was to enable real time monitoring, energy cost allocation, load monitoring, and load control. The university participates in a load control programme that requires some loads to be switched off rapidly (less than one second) whenever the supply frequency drops below a minimum threshold. In order to achieve this, electrical loads are either controlled directly by the meters or through the building management system (BMS) via the UMG604 in each individual building on its network.

The University paid for its required power consumption data. Today, energy consumption data is gathered from the UMG604 meters over the local area network (LAN) and used to allocate the cost of electrical energy to each building and facility. The cost savings from about 18 months worth of data acquisition service were sufficient to pay for purchasing the Janitza® instruments supplied by Direct Control. Direct Control’s technical team helped integrate these instruments into the university’s network by providing the required technical assistance, training and ongoing support.

The current install base has about 50 UMG604 energy meters and more than 40 UMG96 RM slave meters monitoring electrical power consumption in its buildings and networked through their LAN. These meters are now used for load shedding functions and help stabilise the supply frequency almost instantly by utilising some of the programmable logic controller (PLC) functionalities embedded in the UMG604 and acting directly on local loads without delays caused by slow LAN traffic.

The UMG604 meters have their own onboard memory and home page and can communicate with other network elements over an existing LAN using TCP/IP protocol as well as control up to 32 slave meters via Modbus RTU. With digital inputs and outputs, the UMG604 also has the ability to perform some simple PLC functions locally. Energy MAX (load shedding) and cost calculation are some of the additional features of the UMG604. Information on these meters is on www.janitza.com.

Mr Pietsch is impressed by the ease of use and connectivity of these units compared with that of other top-brand instruments he replaced. The IT department is equally impressed as it runs the new functions of Janitza GridVis Service Software on a virtual machine that integrated seamlessly with its existing infrastructure.

With these meters in place, and with many others possibly to come in future, the University of Otago could now easily expand this network and use the web-based Janitza Energy Portal to generate a complete visualisation, monitoring and data analysis of the entire campus. This energy use will provide an invaluable insight toward further cost savings in future.

Direct Control will be showing some of these interesting solutions at the EEA Conference and Trade Show, Stand 108, at Sky City Convention Centre in Auckland from June 18 to 20, 2014.

For more information:

Nabil Garabet

Business Development Manager

Direct Control

Phone: 09-300-4300

Email: [email protected]

Visit: www.directcontrol.co.nz