Terry Mackenzie Hoy

Terry Mackenzie HoyWorking Knowledge by Terry Mackenzie Hoy looks at the electrical industry from an electrical engineer’s perspective and offers valuable advice to everyone in the electrical profession – including young apprentices, self-employed electrical contractors and electrical engineers. With about 40 years in the industry, Terry draws on some of his own experiences as the background to his columns and to illustrate his point. He encourages integrity and ethical business practices and, above all, safe working practices. Sometimes humorous, always honest, Terry’s columns cover topical issues in a pragmatic, no nonsense style and, when necessary, he shoots from the hip.



Terry says that, for electrical contractors, cash flow is one of the biggest problems facing small electrical businesses and he gives some advice on how to keep the wolf from the door. Read more...



This column discusses PILC and XLPE cables and the problems associated with ‘dendritic water trees’. If you are going to use XLPE cable, use South African made products, says Terry. Read more...



In March, Terry looks at the ‘system’ whereby, when tendering for a contract, contractors name an amount for completing work on time, another amount for working safely and a further amount for good quality of work. If the targets are met, they are rewarded, however, if the targets are not met, they are penalised. Read more...



This column sees Terry talk about motor control centres and he gives some interesting background to the development of motor control centres. “A well-designed MCC is a pleasure. And a badly designed one is a nightmare. An overdesigned one is silly,” he says. Read more...



In his May column, Terry delves into motor control systems and the importance of remote starting and stopping, which, says Terry, is a matter for careful consideration. Read more...



In his June column, Terry talks about energy contractors and gives some pointers as to what constitutes good energy saving and what doesn’t. Read more...



In his July column, Working Knowledge, Terry relates three tales that summarise why electrical contractors should regard personal safety and the safety of all work on site is extremely important. Equally important is to remember that lawyers make money out of one party claiming from another. No matter how much time elapses or how unlikely the claim, they will claim if they can. And they will claim from you. Read more...



In his August column, Terry Mackenzie Hoy discusses ‘the grid’. “We can comprehend the apparent scale of the National Grid when we consider that the energy consumption of South Africa is the same per capita as the combined consumption of Botswana, Namibia, Zambia and Zimbabwe.” Read more...



In his September column, Working Knowledge, Terry Mackenzie Hoy discusses a situation he encountered with a counterfeit relay and explains the Law of Delict when it comes to installing counterfeit devices – even if this is done unknowingly. Read more...



In his October column, Working Knowledge, Terry Mackenzie Hoy indulges in a little retrospection about some hair-raising experiences he has had during his long career, and appeals to young electricians to “observe and think” when confronted with anything that doesn’t make electrical sense. Read more...



In his November column, Working Knowledge, Terry Mackenzie Hoy says that most municipalities have finally accepted that there are people who would like to generate their own power; and the only stable, reliable way to do it, is to connect it to the municipal grid. “Having accepted that private generation will occur (it is now called ‘embedded generation’), there are a whole lot of guidelines that have been published, which contain recommendations from NRS and various municipalities,” he writes, and adds:” This is where the paint hits the carpet.” Read more...



In his final column of 2016 Terry Mackenzie Hoy says that many emerging contractors underestimate the enormous amount of paperwork associated with getting a contract. And, when the correct paperwork is not submitted, this can delay payment of invoices and impact the cash flow. Read more...


January 2017

In his first column for 2017, Terry Mackenzie Hoy predicts that more electrical contractors will get involved in the installation of solar PV power generation projects – something many have been reluctant to do because the technology is regarded as ‘new’ and they are unfamiliar with the technical terms. Read more...


February 2017

In his February column, Terry Mackenzie Hoy highlights a common problem in South Africa – that, although it is a requirement of the OHS Act that work on an electrical installation must be supervised by a registered installation electrician, this doesn't always happen. Read more...


March 2017

In this month’s column, Terry Mackenzie Hoy discusses two things that need to be considered when choosing a cable to supply a load:  the current handling capability of the cable and the volt drop at the point of connection to the load. The current handling capability of cable is to be found in tables in SANS 10142; but all is not as simple as it sounds. Read more...


April 2017

This month, the inimitable Terry Mackenzie Hoy apologises to our readers for a mistake in a previous column, thanks Kevin Welch of UIC Automation (Pty) Ltd. for pointing out the error and then moves on to discuss electric motors, more specifically single phase motors. Read more...

Contact Sparks Electrical News

Title: Editor
Name: Karen Grant
Email: sparks@crown.co.za
Phone: +27 11 622-4770
Fax: +27 11 615-6108

Title: Advertising Manager
Name: Carin Hannay
Email: carinh@crown.co.za
Phone: +27 11 622-4770
Fax: +27 11 615-6108

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