. It
is colour-coded orange for general electrical wiring, white for emergency
lighting red for fire alarm wiring. 6.3
MI cable with terminating seal and gland. These characteristics often
make the only cable choice for hazardous high-temperature installa-
tions such oil refineries and chemical works, boiler houses and furnaces,
petrol pump and fire alarm installations.Basic Electrical Installation Work
126
conductor (CPC) and the cable simply terminated using compression
gland.
The cable has small overall diameter when compared alternative
cables and may supplied bare copper with PVC oversheath.3).
MI cable
A mineral insulated (MI) cable has seamless copper sheath which makes
it waterproof and fire- and corrosion-resistant.2
A four-core PVC/SWA cable. The copper outer sheath provides the
CPC, and the cable terminated with pot and sealed with compound
and compression gland (see Fig.
Conductors
embedded in
magnesium
oxide powder
Gland
body
Cable sheath
also CPC
Gland
nut
Compression
ring
Sealing pot
screwed cable sheath
by self-tapping thread
Sealing disc
Conductors
Sleeve
FIGURE 6.
The copper conductors are embedded white powder, magnesium
oxide, which non-ageing and non-combustible, but which hygro-
scopic, which means that readily absorbs moisture from the surrounding
Stranded copper
conductors
Inner plastic
sheath
Colour-coded
cable insulation
Galvanized
steel wire
armour
Outer plastic
sheath
FIGURE 6
