Sparks Electrical News June 2019

CONTRACTORS’ CORNER

5

WORKING KNOWLEDGE WITH TERRY MACKENZIE HOY

TEN THINGS YOU SHOULD BEAR IN MIND AS AN ELECTRICAL CONTRACTOR

Y ou know how it is that you 'Google' something and lists pop up? Lists like ‘Ten things you didn’t know about the royal family’ and ‘10 things to do when you like Donald Trump’? So, here are ten things not to do to keep you safe at work in the electrical world. 1. Don’t wear a watch or jewellery. Take your rings and chains and watches (and studs and piercings) off and put them away safely when you get into your overalls. At some stage of your career you will reach out near live terminals and the ring or the watch will touch them. You can lose a finger or burn your wrist. If you have a pendant, at some stage it will get caught in moving machinery. Don’t argue. Finding out the hard way is ... um, hard. 2. Wear a hard hat. In 40 years of engineering, my hard hat has never been needed to protect me from anything falling on my head. Nothing has fallen on my head. So far. But, when I first put on my hard hat, I didn’t know this would be the case. I still go to

When the driver climbs onto the crane he will be electrocuted. 10. When opening a busbar chamber, do so gently. Take the cover off and let the chamber ‘breathe’. Very often, flammable gases form in such chambers and explode if there are any naked flames in the vicinity. Remember, if there is no ‘source of ignition’, one will soon turn up ... Then there is all the other standard stuff: if you can’t see the face of the truck driver, then the driver can’t see you; get somebody to hold the ladder; if you can’t get somebody then you shouldn’t be working alone; don’t stand on forklift forks to lift you up; and finally, that most often ignored of rules, don’t work on a circuit if it is live. No matter who, no matter what or no matter how, a live circuit is a threat to you. Nobody should make you undo live cable tails, live wires or terminals. Just don’t do it.

pull away reflexively and your hand won’t grasp it reflexively. 7. Wear goggles and gloves when grinding. Heavy gloves for grind- ing with an angle grinder, garden gloves for a grinding wheel. If you are grinding aluminium, the doctor will never get a splinter out of your eye with a magnet. Think about it. 8. Never enter a closed compartment without a gas test. On a mine, four artisans decided to steal lead weight from inside a metal barge. Gas from oil was in the barge and they all died. If you have to enter a closed compartment without a gas test, make sure your will is up to date. 9. Do not let a crane park under a power line. If you see a crane parked under a power line, find the driver and tell him to move it. If the driver refuses, find the safety officer and tell him. The danger is that at some stage the driver will lift the crane jib into the power line and the line won’t trip since the crane tyres insulate the crane.

site and put on my hard hat. It is better to have something stopping you hurting yourself and not need it, than the other way around. 3. Isolate the circuit yourself or watch somebody doing it before you start work on it. If someone tells you the circuit is isolated, check. Use your padlock to lock their lock. Leave a note saying you are working on the circuit. 4. The safe earth is the one you can trust. The safe earth is the one you can see. Buy jumper leads and use them as earths. Never work on an un- earthed circuit. 5. You think some wires or terminals are live? Buy a neon tester which lights up if the circuit is live. It works through cable insulation. 6. If you have to touch a bare conductor, do it with the back of your hand. If it is live your arm will IMPRESSIVE NEW SOLAR HEAT SYSTEMS SAVE MILLIONS T he Austrian Ambassador officially launched two of the largest sub-Saharan solar sys- tems in Johannesburg in May. These SOL- TRAIN (Southern African Solar Thermal Training and Demonstration Initiative) projects, a district heating plant for Wits University residences and a solar process heat plant for the Klein Karoo Inter- national (KKI) tannery, will save millions in energy costs over the lifetime of the plants. SOLTRAIN in South Africa is managed by the Centre for Renewable and Sustainable Energy Stud- ies at Stellenbosch University, and the South African National Energy Development Institute (SANEDI), in partnership with AEE-Institute for Sustainable Technologies (AEE INTEC) from Austria. SOLTRAIN is a regional initiative on capacity building and dem- onstration of solar thermal systems. Wits Junction The Wits Junction district heating project combines solar, co-generation and gas heating technologies, servicing 14 student residence buildings with hot water from one centralised hot water plant room. The installation includes 600 m 2 solar heating plant with 10 m 2 Austrian collectors. There are 1 103 students in the 14 buildings, with an average consumption of 94 000 litres of hot water per day. Peak demand is in the morning, averaging 30% of daily consumption, with a maxi- mum demand of 28 200 litres in an hour. The sys- tem supplies the entire hot water demand, including kitchens, laundry, cleaning and other domestic uses. Each student has his/her own kitchen and there are some centralised service rooms for cleaning staff. Since the system was commissioned, the com- plaints of not having hot water have reduced by 98%. The estimated cost savings are R40 million over the next 20 years and already the University has seen substantial electricity savings over the trial period of eight months. As the electricity cost from the co-generator is equal to municipal cost, the thermal energy is free and the centralised plant requires a lot less maintenance intervention, hence less costs.

Enquiries: www.soltrain.org

SPARKS ELECTRICAL NEWS

JUNE 2019