The function of the cables is to conduct the energy generated by the modules to the inverter and from there to the building grid that is why you need ramps like 5 channel cable ramp to cover it. Losses should be minimal as they represent lost money. And the challenge is that the cables must survive intact for decades – after all, the modules are warranted for 25 years or more.
It is important to remember that we are seeing wires through which direct current passes, generated by the modules. Unlike circuits in the standard electrical installation in alternating current, there is no circuit breaker or other device that trips, cutting off the current.
How Do Protect The Wires?
Underneath the modules, the wires must be fixed with cable ties. Avoid very sharp curves so as not to force the insulation.Cable ties must have UV protection, so do not use white or clear cable ties unless the manufacturer guarantees that protection. Some suppliers for PV systems offer cable ties made of stronger material.
How To Go Through The Tiles?
All wires exposed to the sun must run in ducts such as conduits, cable trays, or corrugated ducts. These also need to be resistant to the sun’s radiation, which precludes the use of conduits. The ducts also protect the wires when passing through the tiles.We need to take special care not to cause infiltration at this point. For example, the shape shown in the image to the side is acceptable on roofs with a steeper slope where there is no reverse flow of rainwater. An additional foam or asphalt blanket seal is recommended.
Another alternative is to drill the tile vertically in the diameter of the duct. Always drill holes in the upper part of the tile and seal the passage well to avoid infiltration. Silicone does not work in this environment.
How To Detect Insulation Faults In Cables
The inverter continuously checks the resistance between the primary circuit and the ground. When it drops below an acceptable minimum value, it shuts down and displays an alarm on the display or remote monitoring.The problem usually appears on rainy days, when water carries the current between the poles, and disappears as the sun dries up the vanishing point.So, watch out for these warnings or generation failures during or after rain episodes.