Step-by-Step Guide: Installing Solar Panel Mounting Rails

Writer：Kaysen

For many solar installers and DIY enthusiasts, installing solar panels is one of the most critical tasks. There are many high-quality installation solutions on the market, such as the Kaysen SolarMount mounting system, and we'll use this as an example to outline the materials needed for a specific application.

 

A simple roof mounting system may require the following items:

 

- Rails (to provide a platform for mounting the modules)

 

- Splices (to connect rails as needed)

 

- Mid clamps (located between each module)

 

- End clamps (to secure the end of the last module)

 

- L-feet or brackets (to secure the rail to the roof)

 

- Flashing (to prevent water leakage)

 

- Grounding lugs (to guide the grounding wire)

 

- Grounding clips

 

1) Estimating Rail Size

 

First, you need to determine how many modules will be placed in each row and ascertain the dimensions of each module and the orientation of the panels (vertical or horizontal). To estimate the total rail size, simply multiply the width of each module (if in a vertical arrangement, or the length if horizontal) by the number of modules in a row. Then, add one inch between each module and two inches at each end of the modules for the mid and end clamps.

 

For example, if installing nine modules with a width of 31.4 inches, you would need 282.6 inches of rail. Adding eight inches for mid clamps and two inches for end clamps results in a minimum of 294.6 inches of rail.

 

You'll find that rails come in predetermined lengths. To achieve the required length, you'll connect two shorter rails using a splice. A 156-inch SolarMount rail would be suitable for this purpose.

 

Each row of modules requires two rails (top and bottom). Therefore, a system with two rows of modules would need four rails. Additionally, since you'll be splicing two 156-inch rails to reach the required 294.6-inch rail length, you'll need a total of eight 156-inch rails.

 

2) Splices

 

To connect two 156-inch rails (to achieve the total required length), you'll need to use one splice bar per splice point between eight rails.

 

3) Mid Clamps

 

The number of mid clamps required is equal to one less than the number of modules in each row. For nine modules, you'd need eight mid clamps per rail. With four rails, that totals 32 mid clamps.

 

Consider the thickness of the module. Since the module thickness used is 1.82 inches, F-type mid and end clamps applicable for modules between 1.77 inches to 1.85 inches would be suitable.

 

Note: You may prefer to use bottom mounting clips instead of mid and end clamps. Bottom clips are cheaper but more challenging to install in large systems.

 

4) End Clamps

 

Four end clamps are required for each row, as end clamps are attached to the ends of each rail. In this case, you'd need eight end clamps for the rows in this array.

 

5) L-Feet or Brackets

 

L-feet and brackets are components that connect your rail to the roof. The number of L-feet required depends on how sturdy of a system you need. In conditions with low snow load or wind speed, L-feet spacing of approximately 5 feet may be necessary. The harsher the conditions, the more L-feet connections and roof penetrations are required. To minimize roof penetrations, heavy-duty rails are available, allowing for longer spans.

 

For this system using a 5-foot rail span, at least six L-feet are needed for every 294-inch length of rail. With four rails, you'd need 24 L-feet for your system.

 

If you prefer to use brackets instead of L-feet, the same calculation applies.

 

6) Flashing

 

The number of flashings needed is generally equal to the number of L-feet or brackets required. In the specified L-feet system, QuickMount PV flashing solutions would be preferred.

 

7) Grounding Clips

 

One grounding clip is needed for every two top mounting clamps (mid plus end clamps). Only one of the two rails in each row of the array requires grounding clips.

 

With 32 mid clamps and 8 end clamps for your system, you'd need 20 grounding clips (two 10-packs of item number 980005).

 

8) Grounding Lugs

 

One lug is needed for each rail span and two for each rail splice. With two grounding lugs needed for each splice in your system and four splices on four rows, you'd need a total of 12 grounding lugs. Grounding lugs are sold in packs of ten, so you'd order two packages of part number 980011.

 

Once you know your requirements, the best way to obtain these products is to contact us and request a quote. You can do so by emailing info@kaysensolar.com