Sparks Electrical News July 2021

CABLES AND CABLE ACCESSORIES

10

WORKING KNOWLEDGE WITH TERRY MACKENZIE HOY

Doing a jippo

I n South Africa, back in the day, if something stopped working and you needed it in a hurry but it couldn’t be fixed in a hurry, then somebody would suggest that you “jippo it”. These days we might use the word ‘hack’ instead of ‘jippo’ – it is sort of the same thing. So, here are six “hacks/jippos”: First: I have written before about load testing a generator. To repeat: If the generator is rated at 100 kVA or less, proceed as follows: Obtain the following: 210 litre steel drum with the lid removed, 80% full of tap water, mounted on a wooden pallet; 150 amp three phase circuit breaker, 5 kA; wood strip: 500 x 40 x 12 with three holes drilled in it, one at the centre and the others at 200 mm from the centre; three 500 mm long metal threaded rods; and three 16 mm insulated fly leads. Bolt the threaded rods into the wood so that the tops of the rods are about 20 mm above the wood. Connect the top of each rod onto a fly lead and onto the out- put of each phase of the circuit breaker. Connect the generator output to the circuit breaker input. Immerse the rods in the water, resting the wood strip on the sides of the drum so the rods dangle in the water. Start the generator. Close the circuit breaker. Measure the current in the fly leads – it should be low. Now add salt to the water, a teaspoon at a time. The generator will gradually load up. If it reaches full load, let it run for a few

minutes, stopping when the water boils. If the generator voltage drops to low load and the voltage collapses, the automatic voltage regulator is not working. Take care! Stay away from the drum . And yes, it does work. Second: Say you need to supply a load for a short time, but you have not got a cable with enough capacity. Solution: run the cable through a hose and fill the hose with water. You can easily double the normal current the cable can handle. Third: Emergency transformer: If your transformer is overloaded you can balance a garden sprinkler on it and you will be able to run it 20% over- load (but not if it has open bushings). Fourth: Let us say there is a large motor which, when you want to get it up to speed, requires that you bypass all the trip circuits since it grossly over- loads the power supply which then trips. To get it up to speed with ease, buy a variable speed drive rated at about 15% of the motor rating. Con- nect the output of the drive to the motor terminals via a circuit breaker. Set the current limit on the drive to 110% and start the drive. The motor will turn and accelerate slowly and then, after about 10 seconds, the drive

will trip. Wait 10 seconds and restart the drive. Repeat until the motor is at about 60% speed. Close the motor circuit breaker and the motor will quickly run up to full speed. Fifth: You need a good temporary earth but have no copper rods etc., So- lution: Use reinforcing bar. Diameter does not really matter. Space at 2 m intervals and hammer 2 m into the ground. Connect all the tops sticking out with fencing wire. In addition, if you are laying a cable in a location where there is a high theft rate, don’t lay a bare copper earth wire with the cable. Use 12 mm 19 strand stainless steel rigging wire. Make sure it is fixed at both ends. It does not rust and is impossible to cut. Sixth: And finally… say you have a small generator and it makes a big noise when it runs. You need a silencer. Proceed as follows: Get a 210 litre drum, cleaned out of any oil or inflammables. Using galvanised pipes, connect one pipe to one end of the drum and the other to the other. Bury the whole arrangement but leave the pipes sticking out the ground. Then connect one pipe to the exhaust outlet of the generator. Voila! Homemade silencer…

Easily double your cable identification speed I f you are still using old technology, the time you have to get your work done seems to disappear. Old processes slow you down, rework creates bottlenecks and errors can bring things to a full stop. Help keep things running smoothly by automating your identification. Brady offers a family of print-and-apply machines that take the manual labelling process out of your hands so you can move through your work more efficiently and with less rework. With these modern automated machines, you can: • Increase productivity – cut labelling time in half to keep your output numbers high. • Reduce errors – get sustainable, consistent identification without the rework. • Make changes fast – intuitive full-colour touchscreen and user interface make changing settings easy. 10 seconds faster per cable Wraparound and flag labels can be applied up to 10 seconds faster with Brady’s automated cable identification solutions. The Wraptor A6200 wrap printer applicator for wrap-around labels in cellular manufacturing and process-driven assem- bly. Greater flexibility now comes in a lightweight, compact size. It’s a new, automated labelling device from Brady, and it’s built to boost your efficiency. Meet the Wraptor A6200 wrap printer applica- tor The Wraptor A6500 wrap printer applicator significantly increases production output by identifying cables with wrap- around labels in 5 seconds. With the BradyPrinter A5500 flag printer applicator, operators can significantly increase production output by flagging cables in 5 seconds. Great reliability Dedicated labels are available for maximum reliability when using Brady’s automated identification solutions. The labels themselves are of great quality and can resist challenging in- dustrial environments. All identification materials have been tested using standard ASTM test methods for optimal reli- ability as described in the technical datasheets.

Highly innovative electrical cable solutions

W ith over 65 years of experience, Prat- ley prides itself on the production of highly innovative electrical cable glands, electrical junction boxes and related accessories. Those variants for use in hazardous locations com- ply with international IECex Standards for Ex n, Ex e and Ex d explosion protected equipment. Many Pratley cable glands and boxes also comply with the European ATEX directive. Pratley products can be found in many inter- national mines, petrochemical plants and col- lieries including those of Sasol, Caltex, Natref, Anglo Platinum, Anglo Gold, Mosgas Offshore, Siemens, AECI, Amcoal and many more. Its market leading electrical products serve the in- dustrial, mining, construction, petrochemical and consumer markets in many countries around the globe. Pratley manufactures over 800 products, has filed more than 350 patents world-wide and is an ISO 9001:2008 accredited organisation. A world first The Pratley Taper-Tech® Ex d/e Flameproof En- viro Compression Cable Gland is an ultra-tough, corrosion resistant encapsulated brass cable glands for unarmoured cable. It is fully certified to SABS (MS-XPL/18.0668X) and IECex (ICS 20.0006X) standards and is suitable for use in Zones 1, 2, 20, 21 and 22. No special tools or spanners required, as well as no external clamping. The compression gland is suitable for use in installations from -20°C to 95°C and underground mines. Furthermore, it is IP 66/68 rated to an incredible 350m underwater continuously. The gland is also resistant to corro- sive environments, as well as being oil and grease resistant. Cable gland training The Pratley Training Centre was opened in 2004 and comprises a modern, fully equipped lecture room and practical workshop area of more than 300 square meters. Pratley cable gland train-

ing is aimed at creating a culture of quality and distinction among learners, electrical artisans and engineers. This is achieved by educating on the importance of correct cable termination and electrical product selection. Since inception, we have trained more than 5000 learners, artisans and engineers from South Africa and abroad. Aligned with Pratley’s famous Policy Statement, the courses equip artisans with skills needed to gain maximum benefit from Pratley Products. The most popular workshop is a basic theoretical and practical cable glanding workshop focusing on the fitting of cable glands in non-hazardous and haz- ardous locations. Typical workshop contents: • Lectures on the design and function of a ca- ble gland. • Lectures on hazardous locations and applica- ble equipment. • A practical session, including how to select

the correct size cable gland, cable prepara- tion and how to fit a cable gland and rubber shroud to a length of cable. • A brief introduction to the theory of Ex n and Ex e enclosures, followed by flameproof theory. • A practical session on installing a Flameproof Cable Gland. • Tour of the Pratley Research, Development and Testing Laboratories. In addition, the company offer a ‘Hazardous Lo- cations Seminar’ presented by Eldon Kruger. He is a recognised authority on the subject and past groups have significantly benefited by his interest- ing and informative sessions. These seminars are usually offered to senior management and engi- neers wanting to further of refresh their knowledge on hazardous locations. The company also offer Hazardous Locations training at its Cape Town Training Centre on request.

Enquiries: +27 (0)11 704 3295

Enquiries: www.pratleyelectrical.com

SPARKS ELECTRICAL NEWS

JULY 2021