WILEY

WEEB: High Temperature Acclerated Life Test (HALT)

The WEEB is reliable!

Results: (as of 2/23/07)

With an average elevated rail temperature of +105°C the WEEB has shown no distinct change in continuity or perfomance after a test period equivalent to 38 years* at room temperature. 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 2.3 mΩ.

Testing had to be discontinued after the heater element burnt out. Apparently not as reliable as the WEEB!

An important finding that resulted from this testing is that simply scraping off the oxide coating from both anodized 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 anodized coating off each rail and panel.

* Time at room temperature was estimated using the following rule of thumb: for every 10°C above room temperature, the rate of reaction increases by a factor of 2.

The Test:

1. Two pairs of solar panel frames were attached to a rail using 4 WEEBs.
• One WEEB pair was connected with anti-oxide paste.
• One WEEB pair was 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. Resistance was measured for..
• WEEBs: from solar panel frame to rail, through the WEEB
• Piece of Aluminum: from top of aluminum piece to rail