[RE-wrenches] Hurricanes Forces

[Tom Lane]

Hurricanes wind create both suction up lift and direct pressure against the
glass frame wall of the module -- if a module is to be held securely it
must be attached 1/3 or 1/4 of the way from top to bottom by each of the
two rails . If modules are facing due South and the wind force comes from
the east or west the force will start pealing off one module at at time .
For example if the winds shearing force is from the west the first module
on that end should have an extra rail in the middle with two extra clamps
BECAUSE when that first one goes it will start peeling off each one one at
a time until that wind band passes . It is critical on raise systems on
flat roofs that the two end modules use the struts with two ( 11/2 sets of
mounting hardware per module) and the first three or at least first two
modules be X braced with aluminum L bars bolted with 3/8 bolts across the
back struts in front of and back of the struts with the L bars to prevent
peeling down the row or bank of modules the same as modules mounted flat on
a roof . Enough suction force from high wind speeds can suck the glass
right out of the frame wall - using three rails per module , two each 1/4
of the way from the top and bottom and one directly in the middle can help
. I also suggest using only 60 cell modules in wind zones over 150 MPH with
two rails minimum maybe even three on high rises .The frame walls on 72
cell modules is trying to hold too much glass in place for just two rails
.  On ground mounts that are adjustable lower the array to 15% or less and
on smaller home owner ground arrays attach motorcycle tie down straps on
the end corners and middle hooked to extra D rings attached to the array (
especially to the corners of Top of Pole Racks ) to mobile home screw in
ground anchors AND if possible strap plywood over the glass front .
GatorTom PS : having insurance is a good investment when a monster 100'
Live Oak tree topples forward onto your array . Or a car or boat gets blown
onto your roof .
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