Cables of Solar PV Power Plant Installation

The performance, quality, safety and profitability of a PV power plant doesn’t only depend on the workmanship, efficiency of PV modules and the reliability of the inverter installed, but also on the components that connect them within an electrical system.

Cables are often not considered to be a highly critical factor, however, neglecting correct cables and using material that is not suitable for solar PV applications can compromise the overall performance and expected downtime of the PV power plant. Cables and wires can be considered as veins of any electrical power system including a PV power plant. The energy generated at PV  modules passing though Junction Boxes, to the Inverter and later the interconnection point with the grid is facilitated by deploying a proper and effective network of cables.

As these cables are used both indoor & outdoor for flexible and fixed installations to perform in highly extreme weather conditions.These cables can be categories into two based on their functions:

1. DC Cables

Installed on the DC side of the PV system, before the inverter input, the AC cables specification must include:

  • General
    • UV-resistant,
    • Rated for > 1100 VDC, outdoor use
    • If overground then UV-hardened PVC conduit
    • If underground then Armoured
  • From PV module to junction box
    • 4 mm2 or 6 mm2, 1C multi-stranded Cu
    • MC4 or equivalent PV connector
  • From junction box to inverter
    • Multi-core Cu
    • Cross-section as per design (capacity & length) to limit DC cable losses <2%

2. AC Cables

Installed on the AC side of the PV system, after the inverter, the AC cables specification must include:

  • Design & construction
    • Al or Cu,
    • Cable cross-section as per the design to limit AC cable losses < 2%
    • Termination with suitable lugs & sockets, crimped
    • Passed through compression-type cable glands
  • Underground cable
    • Should be armoured
    • Laying depth: 1.5 mtr
  • Marking
    • Marking on cable every 1 mtr
    • Cable marking: Punched Al tags
    • Cable routing should be clearly marked

Features of a Solar Cable

  • good weather- and UV-resistance, as solar cables, lay usually outdoors and are subject to direct sun radiation and air humidity
  • withstand high and low temperatures and thus be used within a temperature range of usually between -40°C to 90°C
  • withstand mechanical stress from pressure, bending or stretching as experienced during installation
  • be resistant to abrasion, therefore most sheaths are made of plastics cross-linked using electron beam
  • withstand stress in the form of alkaline solutions and saltwater.

The post ID for this chapter is 3385. For any suggestion or comment regarding the content, you may write to us at faqs[dot]solar[at]gmail[dot]com. Please quote the post ID in the subject, for better assistance.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.