One of the most impressive things about walking around (at least most) utility-scale PV sites, is how neat, orderly, and consistent the cable management is. Unfortunately though this might be covering up some of the issues that happened during the install phase. Issues that create weak points and compromised components, which can create serious problems during operation.
One of the most prevalent of these is the module connectors and cables being allowed to hang exposed, often laying on the ground in mud and debris, for literally weeks and months before being ultimately connected and constrained into place. This almost always results in contaminated sealing surfaces, electrical contact surfaces, and crimped cable connection inside the unmated connector. This creates a no-win situation because either:
- They get mated as-is and the contamination compromises the function and effectiveness of mated connectors, or
- Some sort of cleaning routine is used and the contaminants are lodged further into the open connectors (with no assurance that all contaminants have been removed from sensitive areas), and cleaning solvents or lubricants are used that have a high likelihood of compromising the polymeric materials or mating surfaces of the connector.
Both of these conditions have a high probability of creating future issues such as water ingress, cracked insulators from environmental stress cracking, or high-resistance electrical connections from contaminated mating surfaces. On top of that, both are most likely going to void the warranty from the connector or cable harness manufacturer.
It is absolutely essential to protect the open connections on modules and eBOS components, from the moment they leave the delivery truck to the moment they are plugged in. This means even the unopened shipping cartons of the products (such as modules and inverters) need to be protected from getting wet or soiled, as this too can result in compromised connectors. It is best practice to use protective caps, designed to both seal and protect the open connectors, and to make certain all loose cable leads are kept up off of the ground plane and secured confidently until it is time to plug them together and do the final cable securement.
Not doing so can lead to a systemic and costly O&M event down the road, often within the first 3-5 years.
Brian Mills, Product Manager Alternative Energy, North America, Staubli.
— Solar Builder magazine