Cables

Modern Cables

T&E

• L&N are PVC insulated, earth conductor is bare
• All 3 are sheathed with PVC
• Most domestic cable is T&E

Singles

• PVC insulated single conductors
• Used for a minority of domestic work
• For earth & equipotential bonding
• Standard cable for use in conduit

LSF

• Low Smoke & Fume
• Available in pretty purple

Armoured

• For outdoor & garden use

MICC

• aka pyro
• Copper tube sheath with mineral oxide insulation
• Fireproof
• Rigid
• Occasionally seen in domestic premises, mainly in blocks of flats
• Prone to absorbing moisture from the air
• Hence does not always combine well with RCDs
• Special cable terminations required
• Ideal for flammability risk areas, eg traversing a thatched roof.

Historic Cables

Paper

• Paper insulation
• From the WW1 era
• Very rare now

PBJ

• PolyButyl Jute
• Common mains incomer insulation,
• Lots of old PBJ is still in service

Lead sheathed

• Common in 1930s for socket circuits
• Used as exterior farm cable well after that
• Lead sheath does not make good earth connections
• Rubber interior insulation

VIR

• Rubber insulated wiring
• The most common historic wiring
• Twisted pair cotton/rubber was very common
• Rubber insulation perishes, cracks & falls off
• Most VIR wiring is now in a very bad way
• If you have a VIR instalation in use you have a safety problem.

Aluminium

• Cheaper alternative to copper
• Used at one time until its risks were realised
• Aluminium cable creeps, oxidises & fractures.
• Fire risk
• Requires special connections, do not connect to old ali cable using connectors intended for copper.
• Al requires a larger conductor size than Cu for the same current rating

Copper clad aluminium

• An attempt to improve the properties of ali cable
• Significantly better than al, surface oxidation is eliminated, creep reduced & the cracking risk more or less eliminated

T&E

• 7/.029 T&E
  • imperial stranded version of 2.5mm^2 T&E
• Ashathene T&E
  • Precursor to PVC T&E
• PVC outer VIR inner
  • an early T&E cable
• 2 core T&E
  • no earth, used for lighting circuits

See Also

Wiki Contents

Wiki Subject Categories

Cable Sizes

Wiring colour codes