Outline of Low-Sag Aluminum Conductor Carbon Fiber Reinforced

Summary

With its special carbon fiber core, ACFR conductors achieve both lighter weight and less liner expansion than a conventional ACSR, and display the following excellent characteristics:

• Securing the greatest clearance between conductor and ground level
• Increasing power transmission capacity and reducing conductor sag（ACSR⇒TACFR）

Advantages of Carbon Fiber

Fig. 1 Production process of CFCC

Carbon Fiber (CFCC: Carbon Fiber Composite Cable) used for the core of ACFR has the following characteristics (refer to Fig. 1):

• Weight is approximately 1/5 compared with steel stranded wire
• Thermal expansion coefficient is approximately 1/12 compared with steel stranded wire
• Tensile strength is the same grade as steel strand wire

Characteristics and Construction Menu

Fig. 2 External appearance of (T)ACFR160mm²

There are two types of conductors with the CFCC core: ACFR, the normal CFCC core combined with hard drawn aluminum wires; and TACFR, a thermal-resistant type CFCC core combination with thermal-resistant aluminum alloy wires (refer to Fig. 2, Comparison Table).

• Weight is approximately 70 percent compared with ACSR
• Thermal expansion coefficient is approximately 1/12 compared with ACSR (Above transition temperature)

Characteristics of Sag and Temperature

Fig. 3 Sag/temperature characteristics of
(T)ACFR 160mm²

The sag of ACFR at its continuous allowable temperature of 90゜C can be decreased approximately 2 meters compared with ACSR, and the sag of (T)ACFR at its continuous allowable temperature of 150゜C can be decreased approximately 2.8 meters compared with (T)ACSR, when strung over a span length of 300 meters.

Table 1 Comparison of (T)ACFR160mm² and (T)ACSR160mm² conductor characteristics

Conductors		ACSR	(T)ACFR
Nominal size[mm2]		160	160
Strands[Number/mm]		AL 30/2.6 ST 7/2.6	AL 30/2.6 CFCC 1/7.8
Outer diameter[mm]		18.2	18.2
Calculated cross-sectional area[mm2]		196.5	196.5
Weight[kg/km]		732.8	502.5
Tensile strength[kN]		Min. 68.4	Min. 68.9
Modulus of elasticity[mm2]	Transition temp. or below	89,100	76,000
	Above transition temp.	206,000	137,000
Co-efficient of linear expansion[/゜C]	Transition temp. or below	18.0×10-6	15.5×10-6
	Above transition temp.	11.5×10-6	1.0×10-6
DC resistance at 20゜C[Ω/km]		0.182(0.185)	0.182(0.185)
Continuous current capacity[A]		454[ 90゜C] (705[150゜C])	454[ 90゜C] (705[150゜C])

Note: The numerical value inside the parentheses ( ) shows the electric resistance and continuous allowable electric current values for TACFR and TACSR