Issue 123 November - December 2017

Please note: The issue content below is just a summary of the articles in the printed magazine.
The articles are not available on-line. Please refer to the printed magazine for the complete article.
New industry specific drives from ABB

For industrial plant managers the battle to cut energy costs, improve productivity, increase plant reliability, lower opex and capex, and address stricter environmental and workplace safety regulation never stops.

But whatever the pressures for improvement are on your site, you can find a willing ally in the ABB drives business and the products and engineering support they can bring to achieve any and all of these objectives, says ABB’s Drive Business manager, John Keir.

He says the ability of the latest ABB variable speed drives to improve the control of motors and the processes they govern, put VFD upgrades centre stage in lifting the performance of every industrial site.

“Whether it’s replacement, upgrade or a green-field development, the latest generation of ABB low voltage drives provide the best platform to optimise the performance of any plant. Over the last five years we have rolled out a series of high-performing industrial and general purpose drives to set our VSD platform for the next ten years.

Managing design risks under new law

The accountability of anyone undertaking an electrical design has gone through several changes since 2010 and has been further rocked by the imposition of the Health and Safety at Work Act which makes designers liable not just for the design of the electrical component of plant and structures, but also the safe workplace use of whatever was constructed from their electrical design.

Because the Health and Safety at Work Act (HSWA) is a one-size-fits-all, performance-based solution overlaying all workplace activities, it clashes with the prescriptive precision of the Electricity Regulations and how electrical design is regulated to manage the unique risks posed by the presence of electricity.

Under section 39, HSWA also goes a step further than the electricity legislation and makes service providers (PCBUs) in the business of designing electrical installations or works, liable for an unlimited number of years after the construction work is completed. This liability includes responsibility for ensuring the building or structure is safe for workers and the public to use the electrical facilities they design for workplaces.

Missing link in MEN evolution

The development of a standardised solution for the introduction of a TT system of supply to eventually replace MEN is now likely to be introduced as an addition to NZS 6114.

Energy Safety’s principal technical advisor Peter Morfee says TT could be introduced in a standard of its own but, with NZS 6114 already covering some types of installations with different supply systems outside the scope of AS/NZS 3000, NZS 6114 could be the place to start.

Work is already underway by Standards NZ to address the urgent restoration of Part 6 to this standard for aviation voltage TNC supplies at 115 and 208 volts (400 Hertz). Once this has occurred Energy Safety will look at adding rules that will allow the controlled use of a TT system in New Zealand buildings.

Morfee says the transition to TT is necessary because the earthing structure intrinsic to the MEN variation of TNC-S system we use has been irrevocably changed. The loss of the metal mass from the conversion of metallic plumbing to plastic has resulted in the increased earthing resistance of electrodes to the general mass of earth and no longer provides the surety of a sufficient level of safety in all circumstances as it once did.

Become the local lighting expert – Part IV beam angles

If you are an electrical contractor who is doing residential work, this series of articles is designed to help you become the local lighting expert and grow your business as a result.

In this issue we look at downlight beam angles because sometimes a selecting a fitting with a typical 40⁰ beam angle can be the wrong choice.

People don’t take much notice of beam angles when choosing a downlight. The most common beam angle for a downlight or retrofit lamp is 40⁰ and most GU10 lamps will be around this angle. Broadly speaking, anything less than about 25⁰ is considered a narrow or spot beam. Over 60⁰ is a flood beam.

An easy way to change the look of a room is by changing the beam angle of the downlights. Narrow spot beams will give pools of light and less light on the walls, making them appear darker. This will make the room feel more moody and atmospheric. Wide beam angles will make the room seem brighter overall, and more open and welcoming.

However, there is a trap for young players: if you choose a wide beam you won’t get any more light because the light is simply spread out over a wider area. There will be less of it in any one place and more could be absorbed in the walls and surrounding areas.

Using light to promote health and wellbeing

In September 2017 Massey University held a symposium on healthy lighting, bringing together experts to discuss the topic ‘using light to promote health and wellbeing’. It was well attended by lighting suppliers, lighting designers, engineers, architects and academics in the field of lighting and medicine.

The relationship between light and wellbeing has been talked about for some years but the seminar speakers made it clear that there is still a lot that we don’t yet know. Some common claims about health and light go beyond what has been scientifically proven. However, some benefits are clearly supported by science.

Following is an overview of the keynote speaker’s presentation. The other speakers’ presentations were equally fascinating, covering topics like lighting for healthy schools and the controversy over the blue light component of white light, and these will be covered in future issues.

Associate professor Guy Warman of the Department of Anaesthesiology at University of Auckland addressed lighting, biological clocks and sleep, and the considerations for architecture that arise from these factors. Warman is a chronobiologist – someone who studies the biology of time. He explained the latest research that shows that adequate sleep and a regular circadian rhythm are essential for our health.