Manually Specifying Racking for Roof Mounted Systems (Part 1)
Panels can be arranged in either portrait (longest side is vertical) or landscape (longest side is horizontal) position. Further, rails can be run either north/south (vertical) or east/west (horizontal). As such, the four permutations below are available:
The formula for determining the length of a particular row or column of panels is as follows (where x = number of panels in column/row):
(x)(length OR width of panel, depending on portrait or landscape) + (x - 1)(space required for each mid clamp) + (2)(space required for each end clamp) = required length of row or column
IronRidge: ¼” for mid clamps, 1.5” for end clamps
Unirac: 1” for mid clamps, 1.5” for end clamps
For example, to determine the space required for a single row of 10 Canadian Solar CS6P-265P panels (dimensions: 64.5 × 38.7 × 1.57 inches) in portrait orientation using IronRidge racking, the equation would look like:
(10)(38.7”) + (10-1)(0.25”) + (2)(1.5”)
= 387” + 2.25” + 3”
The E/W width of the array is 392.25” (32.6875’) and the N/S length of the array is 64.5” (5.375’, equal to the length of the panel).
With this information, we can determine the racking BOM for this array.