As per instructions of Shri SKB Valli Sir safety first in all activities to develop safety culture from bottom to top.
The hazards associated with damaged or missing plastic insulation on High Tension (HT) and Low Tension (LV) cables in a solar plant are severe, primarily revolving around electrical shock, fire, and equipment damage.
Primary Hazards
Electric Shock and Electrocution: The most significant and immediate hazard. Exposed live conductors (due to missing insulation) can cause severe injury or death if personnel come into direct or indirect contact with them. This risk is present in both HT (higher voltage, greater danger) and LV systems.
Fire Hazards: Damaged insulation often leads to short circuits or ground faults. The high power discharge from these faults can generate extreme heat (arc faults/flash), potentially igniting the cable insulation itself, surrounding materials, or the entire solar plant.
Arc Flash and Arc Blast: In high-voltage systems, a fault can lead to an arc flash, which releases a tremendous amount of concentrated radiant energy and hot gases (up to 19,500°C). This can cause severe burns, explosions, and project debris, posing a major threat to personnel and equipment.
System and Equipment Damage: Insulation failure causes overcurrents and voltage issues that can damage expensive components like inverters, combiner boxes, and solar panels, leading to system failure and costly repairs/downtime.
System Inefficiencies and Power Loss: Damaged insulation compromises the integrity of the system, leading to current leakage, increased resistance, overheating, and a reduction in overall power generation efficiency.
Toxic Fumes (in case of fire): If the plastic insulation (especially PVC, a common material in LV cables) catches fire, it can produce dense smoke and release toxic gases like hydrogen chloride, which are hazardous to human health and the environment.
Causes of Insulation Failure
The plastic insulation can fail or come off due to several factors common in a solar plant environment:
Mechanical Damage: Abrasions, cuts, or impacts during installation or maintenance (e.g., from tools, sharp conduit edges, or heavy objects).
Environmental Factors: Prolonged exposure to UV radiation (if non-UV-resistant cables are used), extreme temperatures, and moisture ingress can cause the insulation to become brittle, crack, or degrade over time.
Animal Activity: Rodents or other pests may chew on cables, compromising the protective sheathing.
Improper Installation: Issues such as excessive bending of cables, using the wrong cable size for the current load, or loose connections all contribute to the breakdown of insulation and increased risk of hazards.
Aging: Over time, even with proper installation, insulation materials degrade and become less effective, requiring regular inspection and maintenance.
Mitigation and Safety
To prevent these hazards, it is essential to:
Use appropriate, certified solar-specific cables: These are designed to be UV and heat resistant (e.g., XLPE insulation).
Ensure proper installation: Use appropriate tools, secure cables correctly (e.g., in conduits), and follow manufacturer specifications and local electrical codes.
Conduct regular inspections: Periodically check cables for any signs of physical wear, discoloration, or other damage and replace damaged sections immediately.
Implement safety protocols: Always assume wires are live, use appropriate Personal Protective Equipment (PPE), and ensure systems are de-energized before maintenance.
