Doc Number 801-00015, Version 1.1, Copyright © 2010 Zep Solar, Inc.
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ZEP SYSTEM II INSTALLATION MANUAL
4.2 > Array Layout & Bill of Materials
During the site visit, record information pertaining to the specific roof area where the Modules will be
mounted. This includes roof azimuth angle, roof pitch, dimensions of the mounting area including all
obstructions such as chimneys or vents, the rafter schedule, rafter lumber type if available, roofing
material, and shading factor. Once you have this information, you can begin to create a layout diagram
on paper or with a drawing program that identifies the placement of the array.
NOTE:
Alternately, you can create your layout directly on the roof at the time of installation.
However, since this method will not allow you to confirm the exact quantity of components
ahead of time, it is recommended that you have extra hardware available to account for
unforeseen layout configurations.
When determining the overall array dimensions, calculate ½" gaps per every vertical and horizontal
Module seam.
Consider whether to mount the Modules in landscape or portrait orientation. As discussed above,
landscape orientation usually offers an opportunity to fit more kilowatts of PV Modules on a typical
roof. It will also allow for a more economical use of mounting hardware.
Figure 4.2A illustrates the Leveling Feet with circles at the intersections of the Module frame and
the rafters and Interlocks have been indicated with rectangles where the corners of the Modules
intersect.
On your diagram, draw your rafter layout and then superimpose a drawing of your array in its desired
location. Locate an Interlock at every vertical seam in an east-west orientation as in Figure 4.2A.
Then, mark the Leveling Feet locations according to the maximum allowable spacing determined by
your span tables.
NOTE:
It is not necessary to install Interlocks along the east and west edges of the array.
If the location of an Interlock prevents locating the Leveling Foot on a desired rafter, shift the
Leveling Foot to the nearest adjacent rafter while maintaining span and cantilever requirements.
This is indicated in Figure 4.2A with dashed circles where Leveling Feet have been relocated to the
left due to an Interlock location conflict.
