Analysis of the Underground Service Life and Influencing Factors of PV1-F Cables

Overview of the Underground Service Life of PV1 - F Cables

PV1 - F cables, a common type of photovoltaic DC cable, typically feature copper conductors and cross - linked polyethylene (XLPE) insulation. When installed underground, they generally have a service life of 20 to 25 years, which aligns with the typical operational lifespan of solar PV systems. However, their durability underground is influenced by several key factors.

Factors Affecting the Underground Life of PV1 - F Cables

Insulation and Sheath Materials

PV1 - F cables usually employ XLPE insulation, which is resistant to heat, moisture, and chemical corrosion. They are also equipped with a protective outer sheath, which can be made of materials such as polyvinyl chloride (PVC) or low - smoke zero - halogen (LSZH). These materials can resist underground moisture, soil chemicals, and microbial erosion, which are crucial for the long - term performance of the cables. For example, in areas with high soil chemical content, XLPE insulation and high - quality outer sheaths can effectively prevent cable corrosion and extend their service life.

Underground Installation Conditions

• Favorable Installation Conditions: If the cables are installed in a protective conduit (such as HDPE pipes) or buried in well - drained, non - corrosive soil (low in acids, alkalis, and free of sharp debris), the cables can be protected from physical damage and environmental stress, thereby extending their service life. According to relevant research, when installed with a protective conduit, the service life of the cables can approach 25 years.
• Poor Installation Conditions: Conversely, poor conditions, such as waterlogged soil, high soil salinity, or frequent ground movement, can accelerate the degradation of the insulation layer, shortening the cable's service life to 15 - 20 years. For instance, in coastal areas, due to high soil salinity, the aging rate of PV1 - F cables is significantly accelerated.

Operating Loads

PV1 - F cables are designed for specific DC voltages (usually 1.8kV or 1kV) and current ratings. If operated within their rated load (avoiding overheating caused by excessive current), their insulation performance will remain stable; overloading can cause premature aging of the cables. There are actual cases showing that when cables are overloaded for a long time, their service life may be shortened to 10 - 15 years.

Summary and Maintenance Recommendations

In summary, under standard underground installation conditions (protected by a conduit, suitable soil, and normal PV system loads), PV1 - F cables can be reliably used for 20 - 25 years. Regular inspections (such as testing insulation resistance) can help detect early signs of aging and extend their service life.

FAQs

• Q: What is the general service life of PV1 - F cables underground?
  A: Generally, it is 20 to 25 years.
• Q: How do insulation and sheath materials affect the cable's service life?
  A: XLPE insulation is resistant to heat, moisture, and chemical corrosion, and the outer sheath can resist physical damage and chemical erosion, which are crucial for long - term performance.
• Q: Can poor installation conditions shorten the cable's service life?
  A: Yes, poor conditions such as waterlogged soil, high soil salinity, or frequent ground movement can accelerate the degradation of the insulation layer and shorten the service life to 15 - 20 years.
• Q: Why should the cables be operated within the rated load?
  A: Operating within the rated load can keep the insulation performance stable, and overloading can cause premature aging.