Abstract
Electricity theft and safety hazards associated with overhead distribution networks (energy losses — right-of-way issues in overhead lines) are major challenges for the power industry in Iran and many developing countries. Covered conductors (CCX, CCSX) and aerial bundled cables (ABC) can serve as a technical and economic solution, playing a significant role in mitigating these problems. This paper first introduces the structure and types of covered conductors and ABC cables, then examines the mechanisms of electricity theft and safety risks related to bare-wire networks. Using empirical evidence and field studies, the effectiveness of this technology in reducing theft and improving safety is analyzed. Results show that ABC cables not only reduce non-technical losses and operational costs but also, by eliminating bare wires and insulating conductors, significantly lower the risk of electric shock and fire. Finally, implementation challenges and limitations are discussed, and recommendations for deploying this technology in Iran’s distribution network are presented.
1. Introduction
Electricity distribution networks, as the final link in the energy supply chain, play a vital role in delivering reliable and safe power to consumers. However, non-technical losses (NTLs), mainly due to energy theft and meter tampering, have become a major challenge for distribution utilities worldwide, especially in developing countries. In Iran, official reports indicate that billions of tomans in damages are inflicted annually on the network from electricity and equipment theft. Furthermore, bare overhead conductors traditionally used in low-voltage and medium-voltage distribution networks pose serious safety risks such as electric shock, fire, and short circuits caused by contact with foreign objects.
Covered conductors (CCX, CCSX) and aerial bundled cables (ABC) offer an effective technical response to these challenges. These cables, composed of several insulated and twisted conductors, not only significantly reduce the possibility of electricity theft but also greatly enhance network safety. This paper aims to comprehensively explain the role of this technology in reducing theft and safety hazards.
2. Structure and Types of Covered Conductors
Covered conductors (CCX, CCSX) or aerial bundled cables (ABC) are overhead lines in which current-carrying conductors, instead of being bare, are coated with cross-linked polyethylene (XLPE) or similar insulating materials. Importantly, this covering serves primarily as a protective sheath and does not necessarily provide full electrical insulation. Covered conductors have a conductor with an insulating layer that protects against accidental contact with other covered conductors or grounded components such as tree branches. Compared to fully insulated cables, covered conductors have lower electrical specifications; however, they can temporarily withstand phase-to-ground voltage.
Since covered conductors are unshielded, they are not safe against body contact and, regarding electric shock risk, should be treated like bare conductors. These conductors can be manufactured as single-layer (CCX) or double-layer (CCSX). In the single-layer type, the covering is extruded from high-density polyethylene resistant to environmental conditions, UV radiation, and abrasion, using medium-voltage grade raw materials. In the double-layer type, the inner layer is transparent cross-linked polyethylene without additives (medium-voltage grade), and the outer layer is UV- and abrasion-resistant HDPE (medium-voltage grade). The injection of the semiconducting layer and the covering is done simultaneously with a two- or three-head extruder or via two sequential extruders in a continuous process to ensure effective adhesion, bubble prevention, and increased service life. This structure severely limits accidental contact by persons or objects with the conductor. The conductor core consists of compacted aluminum strands with a steel core, including cross-sections such as Mink, Hyena, Wolf, or alloy aluminum conductors with compaction, covering cross-sections from 70 to 185 mm².
Based on voltage level and application, ABC cables are classified into low-voltage ABC (0.6/1 kV for 400/230 V networks), medium-voltage ABC (up to 33 kV), and spacer cables where conductors are separated by insulating spacers. Reference standards for design and manufacturing include IEC 60287 (current rating calculation) and IEC 61597 (performance tests), along with HD, IEC 60502, and BS EN 5018 series, from which Tavanir Company has compiled its own requirements.
3. Electricity Theft: Definition, Methods, and Consequences
Electricity theft refers to any deliberate action to receive electrical energy without paying legal charges or outside the contractual framework. In bare overhead networks, the most common method is illegal connection using a hook (“Kunda”), where a wire is directly attached to the low-voltage conductor, bypassing the meter. Other methods include meter tampering, direct connection to the service cable, and using series resistors to reduce recorded consumption.
The economic impact of electricity theft is substantial. In Iran, the Deputy of Distribution at Tavanir reported an annual theft of 108 billion tomans worth of high-voltage network wires. Additionally, the CEO of Tehran Province Electricity Distribution Company stated that 25–30% of the network is aging and needs renovation, increasing vulnerability to theft. Beyond direct financial losses, theft increases network losses, reduces system reliability, and imposes extra costs on legal subscribers.
4. Safety Hazards of Bare-Wire Networks
Bare wires in overhead distribution networks introduce several safety hazards:
a) Electric shock risk: Accidental contact by people or animals with live bare conductors can cause severe shock or death, especially in residential areas and public paths where clearances are insufficient.
b) Fire due to short circuits: Contact of tree branches, metal objects, or strong winds with bare wires can cause arcing and fire. ABC cables, by insulating conductors, prevent such faults.
c) Hazards from equipment theft: Thieves cutting live wires or opening connections endanger themselves and others. Cutting ground wires and protective conductors at substations severely reduces network safety.
d) Hazards from illegal connections (Kunda): Non-standard connections made by untrained individuals not only risk electrocution for the thief but can also cause faults and equipment damage.
5. Role of Covered Conductors in Reducing Electricity Theft
Covered conductors create serious obstacles against common theft methods:
a) Hook-proof design: In ABC cables, conductors are enclosed in thick, twisted insulation. To make an illegal connection, the thief must puncture or cut the sheath, which is technically difficult and leaves visible damage. As officials from Pakistan’s distribution company stated, “These cables can be called anti-theft because electricity cannot be stolen from them by hooks.”
b) Increased cost and risk of theft: Piercing the insulation requires special tools and more time. Since this is done at height and under dangerous conditions, the risk of detection and arrest increases.
c) Faster detection: Unlike bare-wire networks where connections can be made and removed quickly without traces, any tampering with covered cables requires physical damage to insulation, which is visible during inspections.
d) Field evidence: A study in Karachi, Pakistan, showed that replacing bare wires with ABC cables reduced feeder losses by 8%. In Iran, the CEO of Tabriz Electric Power Distribution Company cited replacing copper wires with covered aluminum cables as a solution to reduce equipment theft.
6. Improving Network Safety with Covered Conductors
Covered conductors directly and significantly improve safety:
a) Reduced shock risk: In low-voltage covered networks, even accidental contact is less dangerous due to insulation, especially when cables pass near walls or buildings.
b) Fire prevention: Eliminating contact between foreign objects and conductors prevents short circuits and fires, crucial in forests, dense urban areas, and storm-prone regions.
c) Reduced wire breakage and falling: The twisting and presence of a messenger wire give ABC cables higher mechanical strength, reducing breakage and falling that could cause shock or fire.
d) Improved safety in adverse weather: Due to insulation, ABC cables are more resistant to moisture, rain, and storms, reducing leakage current or short circuits from precipitation.
e) Reduced risk from theft: Theft of electrical equipment undermines safety. Replacing copper with aluminum covered conductors reduces theft appeal and enhances safety.
7. Economic and Technical Considerations
Although ABC cables have a higher initial cost than bare wires, they are cost-effective in the long term. Benefits include reduced energy losses (lower power purchase costs), lower maintenance costs (fewer faults from external contact), longer network life, and reduced costs for detecting illegal connections. Improved reliability and fewer outages increase customer satisfaction and provide social benefits.
Technical challenges include the need for skilled labor, potential insulation degradation from UV, heat, and humidity, and the high cost of special connectors (insulation-piercing connectors). However, recent advances in insulating materials and connector design have largely addressed these limitations.
8. Conclusion and Recommendations
Covered conductors (aerial bundled cables) are an effective and sustainable solution to two major challenges in power distribution: energy theft and safety hazards. Their physical design reduces non-technical losses and improves safety, making them ideal for renovating aging networks and developing new ones.
Based on successful international and domestic experiences, the following is recommended for Iran:
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Develop a comprehensive bare-wire replacement program prioritizing high-loss, dense urban, and high-theft areas.
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Upgrade design and manufacturing standards based on IEC and local climatic requirements.
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Train and empower workforce in installation, repair, and maintenance.
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Conduct a full cost-benefit analysis to demonstrate long-term economic viability.
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Promote theft reporting culture and cooperate with law enforcement.
While not a panacea, ABC cables are among the most effective technical tools for improving the security and safety of distribution networks. Investing in them is an investment in a safer, more sustainable future.
References
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Ahmad, Ali, Meeks, Wang, & Younas (2025). “The ABCs of Electricity Theft.” American Economic Journal: Applied Economics.
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Pesco Public Relations (2015). “Against tampering: Locals to have theft-resistant electricity cables.” The Express Tribune.
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Tabriz Electric Power Distribution Company (2020). “Replacing copper wire with self-supporting cable as a solution to reduce theft and increase network safety.” Fars News Agency.
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IEC 60287 & IEC 61597 – International standards for covered cables.
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Internal sources of Iran’s power industry: technical papers and distribution company reports.