Sparks Electrical News September 2016

DISTRIBUTION BOARDS, SWITCHES, SOCKETS AND PROTECTION

17

DO ALL INFRARED WINDOWS WORK WITH ALL IR CAMERAS?

ENCLOSURES PROTECT ELECTRONIC NERVE CENTRES OF SA BUSINESS

I F you want to conduct a live thermal inspection of electrical equipment, the most effective and certainly safest way is via an infrared window. It’s a data collection point that is IR transmissible, which allows meaningful data to be obtained with- out the thermographer encountering the dangers of arc flash. Not only do infrared windows en- sure a best practice approach to pre- ventive maintenance and condition monitoring, however. They also allow electrical systems, previously consid- ered to be too much of a safety haz- ard, to be brought into routine main- tenance. For many companies, this is invaluable as these systems are often critical to the process or operation. A very common question is: Can any brand of thermal imaging camera

ELECTRICAL and automation systems are central to the functioning of businesses and damage to this equipment can lead to expensive delays. It makes sense, then, for companies to source enclosures for electronics and automation with the same care they would use to select the systems themselves. Zanardo manufactures boxes, suspension and roof ven- tilation systems to cabinets for housing network servers and distribution boards,” says Mike Cronin, MD of Elquip Solutions, Zanardo’s local distributor. The company’s product lines make use of casings con- structed from welded steel monobloc structures, and steel sheet drawn-column bearing frames. Side panels, back panels and doors are manufactured in steel sheet with a thickness of 1.5 mm or more, while internal plates come in galvanised steel of 2 mm and upwards.

Features include transparent doors, doors with keyboard andmouse-supporting systems, single or multiple cable entry flanges and polyurethane sealing gaskets. Pre-drilled internal supports for elements mounting and removable shelves on telescopic guides allow for ease of assembly – while the use of thermosetting powders for painting guarantees that Zanardo’s painted sheet products tolerate temperatures from -40 °C to 60 °C. The items are available in multiple sizes and configurations, and the company also manufactures units in stainless steel: junction boxes, hanging boxes and control consoles. Security and safety considerations include PVC locking systems as well as M4 and M6 pins for earthing.

be used with any type of window? Naturally the infrared camera manufacturers will recommend their own brand of window. But, when armed with the necessary infor- mation, companies can make their own decision on the best combination for their business. Quick guide Step 1: Determine the type of camera to be used. Infra- red detectors broadly fall into the wavelength of 1 – 12 microns. Shortwave covers 1 – 3 microns, medium wave 3 – 5 microns and longwave 8 – 12 microns. Longwave, uncooled cameras are the standard choice for maintenance and condition monitoring applications. Step 2: Determine the type of material of the window being considered. The most common used for indus- trial thermography are calcium and barium fluoride, sapphire and IR transmissible polymer. Next consider the transmission range of those materials. Respectively they are .13 to 10 microns, .17 to 5.5 microns and 3 to about 12.5 microns. When you correlate the data from both steps you can see the longwave cameras can’t be used with a sapphire window as the transmission ranges don’t tie up. This means you are left with a choice between a fluoride or polymer based infrared window systems. Both have the correct credentials on paper but which is the most suit- able for industrial maintenance applications? Think, harsh environment Calcium and barium fluoride are crystals which by

their very nature, are fragile. There are certainly ap- plications that are well served by this type of win- dow, particularly in the lab, but they are not the best choice for harsh industrial or uncontrolled environ- ments where mechanical stresses such as vibration are common. These stresses degrade the crystalline structure increasing refraction and decreasing transmission. And as the window becomes weaker it is much more prone to fracture. Even an electrician slamming a panel door closed can cause it to shatter. As a result, the average life expectancy of this type of window, irrespective of whether it is producing valuable data or not, is less than 10 years. Another factor to consider is whether the intended environment for the window is damp or humid. Calcium and barium fluoride are hygroscopic, even when coated. This means an infrared window made from this material will absorb moisture and, over time, this too will compromise transmission rates and render readings inaccurate. That leaves polymer based infrared window systems. For the industrial environment, this type of window has many advantages. It is shatter and impact proof, will not degrade in the presence of moisture, UV or vibration and windows made from this material carry an unlim- ited lifetime warranty. It can also be any size or shape to suit the application.

Enquiries: +27 11 826 7117

Flexible power distribution system

THE range of XL³ modular power distribu- tion enclosures from Legrand complies with international IEC 61439 standards that have replaced IEC 60439. “The certification of enclosures is defined by IEC 61439-1 and IEC 61439-2 for power switchgear and controlgear assemblies. This accreditation formulates the definitions, oper- ating conditions, structural provisions, techni- cal characteristics and tests for low voltage wiring accessory assemblies,” explains says Marc Naidoo, projects and technical co-or- dinator, Legrand SA. “Modifications to these IEC standards encompass three different, but equivalent types for verifying requirements. These are verification by a test, verification by calculation or measurement, or verification by satisfying design rules. Unlike IEC 60439-1, conformity cannot be established simply on the basis of the general rules of the standard. Assemblies must comply with the specific standards dedicated to them. Compliance with standard IEC 61439-2 also enables the CE mark to be attached, if required.” There are 13 standard tests for the certifi- cation of pre-equipped enclosures, which are an additional guarantee of safe operation. Legrand is also committed to carrying out ten type tests. Characteristics that need to be checked include resistance of materials and parts, temperature rise, degree of protection (IP), dielectric properties and short circuit re- sistance, as well as electric shock protection and integrity of the protective circuit. Clear- ances and creepage distances, mechanical operation and electromagnetic compatibility are also important. Standards IEC 61439-1 and IEC 61439-2 also require final checks on all wired assemblies. These checks certify that the essential characteristics linked to safety are fully complied with. Legrand’s XL³ cabinets and enclosures – for sites between 160 A and 6 300 A – provide solutions adapted to meet exact site power distribution needs in industrial, commercial and residential environments. Most impor- tantly, these units comply with every part of the standard IEC 61439 to guarantee reliabil- ity and total protection of the installation. Each model in this range includes a se- lection of sizes, versions and equipment. XL³ enclosures are enhanced by Legrand devices

for optimum protection and efficient distribu- tion. These devices include DMX³ air circuit breakers, MCCBs, DX³ DIN rail mounting cir- cuit breakers, busbars and modular distribu- tion blocks. XL³ metallic or plastic enclosures, with index protection ratings between IP 30 and IP 55, have a short circuit resistance from 20 kA to 110 kA. This flexible power distribution system,

Enquiries: +27 32 946 2805

which can be adapted at any time, includes either standard or optimised dis- tribution. Standard distri- bution allows the user to choose busbars and their supports, with a personal configuration for efficient power distribution. The op- timised distribution system, which ensures freedom of assembly, eliminates the need to create special con- nections upstream and en- sures time savings during installation by being able to connect appliances on pre- equipped units. Also available to opti- mise the design, is user- friendly XL Pro panel de- sign software, incorporating XL Pro Calculator software, which automatically cal- culates the total power consumption, required pro- tection devices and cable selection for the circuit, as well as cascading and dis- crimination solutions.

• Not everyone is aware of the fact that an Olifantsfontein-based company has been supplying vital equipment to the transmission and distribution industry in South Africa and abroad for the past 55 years. McWade Productions was founded in 1965 and is now a leading supplier of locally manufactured Transmission and Distribution Line Hardware, High Voltage Sub Station Interconnecting Clamps up to 765kV, Insulators, Disconnectors, Isolators and Compression Tooling. • Founded in 1965 and is now a leading supplier of locally manufactured Transmission and Distribution Line Hardware, High Voltage Sub Station Interconnecting Clamps up to 765kV, Insulators, Disconnectors, Isolators and Compression Tooling. • It has a substantial manufacturing facility operating in accordance with ISO 9001, to local and international speci cations. • On site facilities include a non-ferrous, sand and gravity die-casting foundry, machine shop as well as tool and die-making facilities. • They provide in-house design, documentation and technical back-up, local and international sourcing of specialised equipment, manufacture, source and supply of full packages for sub stations and line projects and design and consulting services to plan and recommend the most suitable equipment, connections and installation procedures to meet customer requirements. SOUTH AFRICAN... AND PROUD OF IT!

For more information contact Steven Naidoo on 082 904 1105/011 3162262 sales@mcwade.co.za or visit their website www.mcwadeproductions.co.za

Enquiries: +27 11 444 7971

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SPARKS ELECTRICAL NEWS

SEPTEMBER 2016