reconductor
To replace the cable or wire on an electric circuit, typically a high-voltage transmission line, usually to afford a greater electric-current-carrying capability.
reconductor: swap the wire for one that handles more current
Reconductoring is the replacement of existing cables or conductors on an energized or de-energized electric circuit with new cable of different or upgraded specifications. In transmission and distribution networks, this typically means removing old aluminum or copper strands and installing new conductors with higher ampacity, lower resistance, or improved thermal performance. The work is most common on high-voltage lines where aging infrastructure or increased demand requires a boost in current-carrying capacity without rebuilding the entire tower or support structure.
The physical process involves stringing new conductors alongside or over the existing line, then transferring load gradually or de-energizing the circuit to remove old conductors and splice or terminate the new ones. Modern reconductoring often uses Aluminum Conductor Steel Reinforced (ACSR) cable or newer composite-core conductors, which offer better strength-to-weight ratios and lower sag characteristics than older all-aluminum designs. A typical modern ACSR bundle might carry 1,200 to 2,000 amperes per phase, compared to 500 to 800 amperes for equipment installed 40 or 50 years ago.
When and why reconductor
Utilities reconductor circuits for several practical reasons: aging conductors develop surface corrosion and embrittlement that reduces effective cross-section, growing load demand exceeds nameplate capacity, or a line must operate at higher voltage without increasing tower footprint. Reconductoring avoids the enormous expense of replacing pylons, foundations, and right-of-way clearances. The cost remains substantial, typically 200,000 to 500,000 US dollars per mile depending on voltage class, terrain, and whether work occurs live or dead, but it is far cheaper than a new corridor.
The term reflects the literal action: to re-fit or re-install the conducting material. It is distinct from upgrading a substation or rebuilding a line (which may include new towers), and distinct from recladding (renewing insulation sheaths without changing the conductor itself). A reconductored line retains its existing supports, geometry, and routing.
Common failure modes in original conductors include loss of tensile strength from corrosion of steel reinforcement in ACSR, creep or permanent elongation under sustained load (especially in older aluminum), and surface oxidation that increases resistance and heat generation. These defects accelerate dramatically after 30 to 50 years of service in high-salt or high-humidity environments. Reconductoring extends circuit life another 50+ years and often improves reliability metrics such as thermal margin and voltage support during peak demand.