The following checks must be performed during inspection & maintenance:
- Check for cable routing. The cables shall be routed properly and fastened with clamps to avoid damage to the cables. Often times we notice that cables are not properly routed and the cable wires are left hanging. This may cause damage to cables due to rodents, squirrels, and other pests or can cause a hazard when people walk around the terrace.
Fig – Improper cable routing
- Closed Loops and open loops. Many at times we notice that cables are not properly looped. Sometimes the cable loops are very tight or very loose. A loose connection may lead to a fire hazard and tight connections may lead to breakage of the cable.
Fig – Cables looped loosely
- Check that all cable connections are tightened and securely fastened. Check that all cables are properly insulated, without insulation damage. Check for quality of outer sheath and conductor insulation.
- Check whether separate single-core cables have been used for the positive and negative conductors of dc circuits. Check whether unused cable entries have been closed. All unused cable and conduit openings shall be plugged with blind plugs or caps to prevent the entry of dust, insects, squirrels, rats and other pests.
- Check for the quality of conduits (diameter, wall thickness)
Fig – Damaged conduits
- Electrical rooms, niches, switchboards, and distribution boards shall be kept clean and neat. The immediate surroundings of all electrical systems shall be kept clean and free to allow access at any time.
- Check for the proper labelling of cables. PV modules cables are generally tied by ‘cable tie’. Check that they are properly tied with a cable tie and not loosely mounted.
Fig – Cable ties used
- The MCB’s, isolators, connectors, switches, fuses, and other components shall be of ratings that match the cables, wires, and equipment to be protected by these components. Check for all cables and wires shall be of the adequate current rating.
- Cables and wires shall not bypass fuses and breakers. All indoor enclosures shall be of IP 54 or better rating. All outdoor enclosures shall be of IP 65 or better rating.
(Ref: Best Practices in Operation and Maintenance of Rooftop Solar PV Systems in India – GERMI)