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Core for innovative conductor(Overhead conductor)

ACFR (Aluminum Conductor Fiber Reinforced)

ACFR(Aluminum Conductor Fiber Reinforced) has been developed by using CFCC as a core of conductor instead of steel wire like conventional conductor ACSR. ACFR has the great characteristics as follows.※1
Low sag: Improve ground clearance or expand tower span
More current: More transmission capacity compare to the same size and weight of ACSR
Low transmission loss: No iron loss due to non magnetic core and less Joule heating loss for more area of Aluminum at the
same weight of conductor

Thermal resistance grades of CFCC

We have three thermal resistance grades of CFCC for the range of operating temperature of conductor.

  Continuous operation temperature Short time operation temperature
Normal type 90°C 120°C
Thermal resistant type
(T type)
160°C 180°C
High-thermal resistant type (HT type) 175°C 200°C

Construction and Specification of ACFR

ACFR consists of Aluminum wires as conductor and CFCC as a core. You can choose Aluminum round wire or Shaped Aluminum wire(for more cross sectional area) depending on the purpose

  • ACFR with shaped Aluminum wire has about 30% more aluminum areas than conventional ACSR with round Aluminum wire. Yet ACFR has same or lighter weight than ACSR
  • ACFR with shaped Aluminum wire has about the double transmission capacity compare to the same size of ACSR
  • Weight of ACFR is about 70% of that of ACSR.(Both have the same cross sectional area of round wire)
  • Thermal Coefficient of CFCC is less than 10% of that of ACSR core.
Construction of ACFR

Table 1 Specification of ACFR 315/40

  ACFR 315/40 ACSR 240/40
Conductor Annealed, shaped Aluminum wire Alloy, Round Aluminum wire
Core CFCC Galvanized steel wire
Construction Conductor 6/4.98, 10/4.98 26/3.44
Core 7/2.60 7/2.60
Outer diameter [mm] 22.4 21.8
Cross sectional area [mm2] Conductor 311.5 241.6
Core 37.2 39.5
Overall 348.7 281.1
Weight[kg/km] 919 975
Minimum breaking load [kN] 93.9 86.7
Elastic modulus[Gpa] Below thermal knee point 71.7 82.2
Over thermal knee point 155  
Thermal coefficiency [/K] Below thermal knee point 17.9x10-6 18.9x10-6
Over thermal knee point 1.0x10-6 11.5x10-6
DC Resistivity[Ω/km] 0.0892 0.1196
Continuous transmission capacity[A] 1,325 (175°C) 650 (75°C)

Reduce the transmission loss

ACSR generates iron loss (transmission loss) by the cyclic magnetization of the core when it transmits alternative current. But the core of ACFR, CFCC is non-magnetic and never generates iron loss. Furthermore, ACFR uses light-weight CFCC as a core, even when ACFR uses shaped wire to have more area of Aluminum, the total weight of ACFR is not more than the same size of ACSR. By these two effect, ACFR reduces 20% of transmission loss compared to the same size of ACSR when they transmit same current.

Less sagging

Comparing same diameter and same current capacity of ACFR with ACSR, ACFR is lighter in weight, and thermal coefficiency of the ACFR core is smaller than that of ACSR. Calculated sagging of ACFR is 4m lower than ACSR when the condition is same except the material of the core. (tower span=450m)

Cost advantages

For replacement

  • You can gain more transmission capacity or more ground clearance only by the cost of conductor replacement. No need of reinforcing the existing tower nor building new towers.
  • Less transmission loss by the same ground clearance and current.

For newly designed line

  • Shorten the tower height or expand the tower span for its better sagging property(Round wire).
  • Reduce the number of the conductor for its larger transmission capacity(Shaped wire).

Jointly developed by Tohoku Electric Power co., Inc and SWCC SHOWA HOLDINGS CO., LTD.

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