Special processes and fluxes have now been devel-
oped which allow aluminium welded and soldered. Copper toughens with work,
but may annealed, softened, heating dull red before quenching.
Silicon rubber Introducing organic compounds into synthetic rubber pro-
duces good insulating material which flexible over wide range tem-
peratures and which retains its insulating properties even when burned. The overhead cables
of the National Grid are made aluminium conductor reinforced by
a core steel. However, the
magnesium oxide very hygroscopic, which means that attracts mois-
ture and, therefore, the cable must terminated with special moisture-
excluding seal, shown Fig.
.
Definition
Rubber tough elastic substance
made from the sap tropical plants. It
is very good conductor, non-magnetic, offers very good resistance to
atmospheric corrosion and notable for its extreme softness and light-
ness.
Copper forms the largest portion the alloy brass, and used the manu-
facture electrical cables, domestic heating systems, refrigerator tubes and
vehicle radiators.3.
Aluminium
Aluminium grey-white metal obtained from the mineral bauxite which
is found the United States, Germany and the Russian Federation. The alloys are cast into cylinder
heads and gearboxes for motorcars, and switch-boxes and luminaires for
electrical installations.Basic scientific concepts electrotechnology
101
Definition
Thermosetting polymers Once heated
and formed, products made from
thermosetting polymers are fixed
rigidly.
Definition
Synthetic rubber manufactured, as
opposed being produced naturally.
Magnesium oxide The conductors mineral insulated metal sheathed
(MICC) cables are insulated with compressed magnesium oxide, white
chalk-like substance which heat-resistant and good insulator and lasts
for many years. Lightness and resistance corrosion make
aluminium ideal metal for the manufacture cooking pots and food
containers. The magnesium oxide insulation, copper conductors and
sheath, often additionally manufactured with various external sheaths to
provide further protection from corrosion and weather, produce cable
designed for long-life and high-temperature installations.
Definition
Magnesium oxide The conductors of
mineral insulated metal sheathed
(MICC) cables are insulated with com-
pressed magnesium oxide
Copper
Copper extracted from ore which mined South Africa, North
America, Australia and Chile. Plug tops, socket outlets and
switch plates are made from this
material. very good conductor, non-magnetic and offers con-
siderable resistance atmospheric corrosion. 6.
Definition
Silicon rubber Introducing organic
compounds into synthetic rubber
produces good insulating material
such FP200 cables.8% pure copper, the impurities being extracted from the ore smelting
and electrolysis. For electrical purposes refined about
98.
Aluminium alloys retain the corrosion resistance properties pure alu-
minium with increase strength.
These properties make ideal for cables used fire alarm installations
such FP200 cables.
good qualities natural rubber flexibility, good insulation and suitability
for use over wide range temperatures. Copper conductors would too heavy support them-
selves between the pylons. used the manufacture power cables. attractive soft reddish brown metal, copper easily
worked and also used manufacture decorative articles and jewellery
