WILEY

WEEB: Thermal Cycle (+80°C to -20°C)

Reliable enough to withstand harsh temperature extremes!

Results: (as of 2/23/07)

With a rail temperature range of +80°C to -20°C, the WEEB has shown no distinct change in continuity or perfomance after a test period equivalent to 19 years* of natural thermal cycling. Continuity of the WEEB connection was evaluated by measuring resistance from solar panel frame to rail, through the WEEB. The average resistance measured has remained constant and is about 2.1 mΩ.

As a result of this testing we found that simply scraping off the oxide coating from both annodized alumninum surfaces provides the same reliable connection achieved with the WEEB. So, why use the WEEB at all? The time saved and the consistent results achieved by using the WEEB are far superior to scraping the annodized coating off each rail and panel.

* Time is approximated as 1 day per thermal cycle, with the hottest part of the cycle occuring at noon and the coolest part occuring at night.

The Test:

1. Four pairs of solar panel frames were attached to a rail using 8 WEEBs.
• Two WEEB pairs were connected with anti-oxide paste.
• Two WEEB pairs were connected without anti-oxide paste.
2. One piece of anodized aluminum was attached to the same rail (for comparison).
• Anodized coating on both rail and aluminum piece was scraped off before assembly.
3. Heat was applied using resistors attached to the sides of the rail.
4. The assembly was cooled using a sealed refrigeration unit.
5. Resistance was measured for..
• WEEBs: from solar panel frame to rail, through the WEEB
• Piece of Aluminum: from top of aluminum piece to rail