Note: The information contained in this periodical weblog may be outdated. This was my personal weblog published before January 1, 2015. Since then I have been the co-owner and Principal Solar Designer at Florida Solar Design Group.

The Best Solar Installers Pay Attention to Detail

Today was frustrating. I visited the site of a solar electric installation that we narrowly lost to a competitor earlier this year. I’m not going to mention the competitor, nor the job. When I first approached the system, I was quite impressed by the outward appearance. The design concept was actually better than I had proposed. The products used were high quality. But upon closer inspection, there we so many things wrong! The details are where this competitor failed, and the details are where competitors start to differ.

In today’s solar electric market, installing the major components has become easier. Modules have snap together connectors, inverters have integrated disconnects and ground fault protection, and mounting systems are very user friendly. That leaves a lot of time and attention available for other important aspects of the installation. I keep my ear to the track in the industry, reading and researching codes and techniques voraciously, and participating in online forums with fellow professionals. It is plainly obvious that some do not.

Incorrect Grounding
This PV Module is not grounded correctly. A listed grounding lug is required. Note the unused approved grounding hole location just inches away from where a self-drilling screw was used.

One of the hottest topics in PV installations these days is grounding. There is lots of debate on proper grounding procedures. Building inspectors are keen to look for installation errors. I’m not sure if this system has been inspected or not yet, but it should most definitely fail. The simplest way to comply is to use the proper equipment in the first place. Yes, proper grounding lugs are expensive – over $4 each. It’s just a cost that we installers need to build into the price if we are to do a proper installation.

Almost Correct Grounding
Here the proper module grounding lug was used (I think - it's hard to identify the outdoor rated lugs from the cheaper regular ones until they start to corrode). However, it is improperly bonded to the metal mounting structure! Why?!

Many installers don’t dig far enough into the specifications and instructions for the products being used, or into the National Electric Code which governs installation methods. Some don’t even bother with common sense. The real failure, I believe, is that there is no check and balance – no quality assurance or supervision. Usually the guy or gal on-site doing the installation is the company’s “expert” and they complete the installation without a follow-up inspection by another company representative. I understand why that happens. Most of the solar companies in Southwest Florida are small mom-and-pop shops, as is my employer. Employing management (like me) is expensive overhead. Often the licensed individual is the person doing the work, and there is no check and balance at all – nobody off whom to bounce ideas.

Improper Strain Relief
The installer brought the PV wires into a pass-through box using a strain relief - a proper concept. Unfortunately, this strain relief is not intended for outdoor use. Moisture, insect penetration, and rust is inevitable.

Everyone makes mistakes. Some are minor, some are serious. There are some relatively obscure, but very important issues that come up in cable management when installing PV modules. Dangling cables that rub on roofs or hang down from the panels are an eyesore and can cause failures. Most PV installers go to great lengths to make an installation look tidy. Just because it’s tidy, it doesn’t mean it’s correct!

Minimum Bending Radius
The minimum bending radius of most PV lead wires is 5x (USE-2 Cable) or 8x (Type PV Cable) the diameter of the wire. This picture clearly shows a lack of knowledge of this requirement with a very tight bend. This can cause damage to the wire and a safety hazard.
Common Mistakes
This shows a common mistake when trying to keep wiring tidy. The minimum bending radius of the wire is exceeded using these plastic wire ties. There are several other errors in just this one picture!

It is not my intention to besmirch the installer or company that did this job. I really want all of my competitors to do better work. We are in a relatively young industry, and this kind of improper workmanship is a black eye on the industry as a whole. Management, quality assurance, and training are not cheap; however, they are critical functions needed to advance solar in Southwest Florida.


1 Comment

  1. Author

    I have to add one more. This irritates me. You can buy clamps that properly stand-off conduits from the wall. This use of two one hole clamps on either side of the conduit was either an afterthought, or the installer decided to use whatever was on the truck to secure this conduit to the structure. While not improper, per se, it’s just shoddy in my opinion.

    Wrong part for the job

Leave a Reply

Your email address will not be published. Required fields are marked *