Sparks Electrical News September 2016

SPARKS

ELECTRICAL NEWS

SEPTEMBER 2016

• 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

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ENCLOSURES PROTECT

ELECTRONIC

NERVE CENTRES OF SA BUSINESS

Flexible

power distribution system

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.

Enquiries: +27 11 826 7117

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

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 32 946 2805

DO ALL INFRARED WINDOWS

WORK

WITH ALL IR CAMERAS?

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,

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.

Enquiries: +27 11 444 7971

DISTRIBUTION BOARDS, SWITCHES,

SOCKETS AND PROTECTION