FW: Uplift Wind Loading Values: Dead or A Live [RE-wrenches]

ASAP POWER! asap at podnine.com
Mon Jul 21 16:37:10 PDT 2003


Been busy, but wanted to get back to these questions from earlier in the
year...
Wrenches, Jeff, my questions were:

1. Can one really consider downward wind pressure a dead load (vs. live
load)?  If so, why and when?

2. If the weight of service people and equipment temporarily on a roof is
considered in the designed roof's live loading permitting, does it need to
be re-considered in PV array install permitting?

3. How do you calculate uplift load value at different design wind
pressures? (with interpretation of equation)

4. Does wind design pressure for a flush-mounted system (and any tilted
array for that matter) assume that design wind speed is hitting the back of
mounted panels straight on?  If so, is the assumption in the equation?

5. Related, should a tilted array wind loading value be more than a flush
mounted array?  If so, should the safety factor be invoked for these
concerns?

6. Is Uplift Wind Loading = to "Foot Design Live Loading?" (Uni-Rac)

7. Finally, when and where does point loading become a concern and need to
be understood?

8. How do other grid-tieing Wrenches/Contractors go about obtaining wind
load numbers (if) required for permitting plans?

9. There are some on-line calculators for wind-loading on structures out
there but for general use and not for PV on roof or ground mounts.  Does
anyone know if there are specific calculators with PV relevant input?

Peter D
ASAP POWER!

- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://www.topica.com/lists/RE-wrenches/

List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm

Check out participant bios: www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael_welch at sbcglobal.net

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

TOPICA - Start your own email discussion group. FREE!
http://www.topica.com/partner/tag02/create/index2.html
--^----------------------------------------------------------------





More information about the RE-wrenches mailing list