Installation Manual
DynoRaxx Evolution PR Guide to Code Compliant Installation
19 | P a g e 8 6 6 . 6 2 0 . 2 4 1 0 | d y n o r a x x . c o m
V. Load Combinations
Often times, there is a good chance that various types of system loads are acting on a system simultaneously.
Because these various loads provide different cumulative loads, the combination that produces the highest
total system load must be taken into consideration. Hence, this value shall govern the system design. Shown
below are the different cumulative loads as taken from Section 2.4 of the ASCE 7-05. Not all of the
combinations have been shown, only the ones that are relevant to the solar racking system.
Down-Force Loading Combinations:
Uplift Force Combination:
Here D is referred to as the dead load, or the total net weight of the system, while
refer to the sloped snow
load and the wind design load respectively. The use of each of these equations is dependent on the
environmental conditions that are present. For example,
would be applicable when there is a
combination of both the snow and the dead load of the system. However, if there was also a wind pressure
present in addition to these two loads, one would then use
. Similarly
is reserved for cases when
there is only wind loading present in addition to the weight of the system.
Please note that for the “Uplift Force Combination,” the negative value for the wind design load needs to be
used. The negative value signifies the fact that the force is acting away from the surface, not towards.