The document discusses different types of overhead conductors used in transmission and distribution lines including stranded conductors, AAC, AAAC, ACSR, ACAR, smooth body ACSR, expanded ACSR, and ACCC. It provides details on their construction, materials used, properties and applications. Stranded conductors have increased flexibility and mechanical strength. AAC uses aluminum and is used where corrosion resistance is important. AAAC and ACAR use aluminum alloys for improved strength and properties over AAC. ACSR combines aluminum and steel. ACCC uses a lightweight carbon-fiber composite core.

1. OVERHEAD CONDUCTOTS
SUMBUL.H.Abidi

2. Stranded Conductors
•Flexibility
•Mechanical Strength increases
•Central strand surrounded by
successive layers
•6,12,18,24
•n=no of layers
•Total conductors=1+3n(1+n)
•Overall diameter of n layer stranded
conductor D=(1+2n)d

3. AAC ( All-Aluminium
Conductors )
 Concentric lay stranded Aluminium Conductor ( AAC) is made up of one or
more strands of hard drawn 1350 aluminum alloy.
 These conductors are used in low, medium and high voltage overhead lines.
 AAC has seen extensive use in urban areas where spans are usually short but
high conductivity us required.
 Because its relatively poor strength to weight ratio, AAC had limited use in
transmission lines and rural distribution because of long spans utilized.
 The excellent corrosion resistance of aluminium has made AAC a conductor of
choice in coastal areas. Because of its relatively poor strength to

4. AAAC ( All Aluminium Alloy
Conductors )
 Concentric lay stranded Aluminium Alloy Conductors (AAAC)
are made out of high strength Aluminium-Magnesium-Silicon
Alloy.
 conductors are designed to get better strength to weight ratio and
offer improved electrical properties, excellent sag-tension
characteristics, and superior corrosion resistance when compared
with ACSR.
 As compared to a conventional ACSR conductor, the lighter
weight, comparable strength & current carrying capacity, lower
electrical losses and superior corrosion resistance have given
AAAC a wide acceptance in the distribution and medium & high
voltage transmission lines..

5. ACSR (Aluminium Conductor Steel
Reinforced )
 Aluminium Conductor Steel Reinforced (ACSR) is concentrically
stranded conductor with one or more layers of hard drawn
aluminium wire on galvanized steel wire core.
 The core can be single wire or stranded depending on the size.
Steel core wire is galvanized to protect for corrosion protection.
Additional corrosion protection is available through the application
of grease to the core or infusion of the completed conductor with
grease.
 The proportion of steel and aluminium in an ACSR conductor can
be selected based on the mechanical strength and current carrying
capacity demanded by each application.

6. ACSR Contd
 ACSR conductors are recognized for their record of
economy, dependability and favourable strength /
weight ratio.
 ACSR conductors combine the light weight and
good conductivity of aluminium with the high
tensile strength and ruggedness of steel.
 In line design, this can provide higher tensions, less
sag, and longer span lengths than obtainable with
most other types of overhead conductors.

7. ACSR

8. ACAR (Aluminium Conductor
Alloy Reinforced )
 Aluminium Conductor Alloy Reinforced (ACAR) is formed by
concentrically stranded wires of Aluminium on high strength Aluminium
-Magnesium -Silicon(AlMgSi) alloy core.
 The number of wires of Aluminum & AlMgSi alloy depends on the cable
design. Though the general design comprises a stranded core of AlMgSi
alloy strand, in certain cable constructions , the wires of AlMgSi alloy
strands can be distributed in layers throughout the Aluminium strands.
ACAR has got a better mechanical and electrical properties as compared
to an equivalent ACSR, AAC or AAAC.
 A very good balance between the mechanical and electrical properties
therefore makes ACAR the best choice where the ampacity, strength
and light weight are the main consideration of the line design.
 These conductors are extensively used in overhead transmission and
distribution lines.

9. Smooth body ACSR conductor
• They are also called compacted ACSR
• The conductors are pressed through dies to flatten the aluminum
strands into segmental shape.
• The interstrand space id filled and the diameter of the conductor
is reduced without affecting electrical and mechanical properties.
• For the same aluminium area the steel core diameter is increased
so mechanical strength is increased.
• Can be used for long span length.
• ACSR/TWD is ideal for reconductoring: it offers the same
diameter for ice and wind but loading at higher ampacity than
traditional ACSR designs.

10. Expanded ACSR Conductor
A plastic or fibrous material is introduced
between the steel core and almunium strands
to make diameter of the conductor large to
reduce corona loss and radio interference

11. ACCC ® (Aluminum Conductor
Composite Core)
•The new Generation, highly energy efficient ACCC®
(Aluminum Conductor Composite Core) is a concentrically
stranded conductor with one or more layers of trapezoidal
shaped hard drawn and annealed 1350-0 aluminum wires
on a central core of light weight Carbon-Glass fiber
composite.
•The ACCC® Conductor uses a carbon fiber core that is
25% stronger and 60% lighter than a traditional steel core.
This along with trapezoidal shaped aluminum strands help
to increases the aluminum content in ACCC® by over 28%
without increasing the conductor’s overall diameter or
weight.

12. ACCC ® contd
 ACCC® is designed to operate continuously at elevated
temperatures and has excellent sag characteristics through
out the operating range.
 ACCC® is the right choice if reconductoring of the existing
lines are required to enhance the transmission capacity.
 This conductor offers very low line losses and excellent self-
damping properties. Because of it's high strength to weight
ratio, ACCC® can be used with long spans which brings
down the cost of structures in new lines