DQRID : D011019.8
Start DateStart TimeEnd DateEnd Time
TWP/SKYRAD/C2 - Solar tracker failure
DataStreams:twpskyrad60sC2.a1, twpskyrad60sC2.b1
During Reset7 (8/6) the skytracker firmware was upgraded for Y2K.  While still at the 
site, the mentor noted that the tracker was sticking and replaced it on 8/8/99. The 
replacement tracker also failed.  Repeated attempts through 8/13 were not successful.  After 8/13, 
the tracker was not operational.

It was found that the problem was the result of bugs in the Y2K compliant version (2.44) 
of the firmware.  On 10/14, Jeff Zirzow installed a new tracker with the Y2K non-compliant 
version (2.43) of the firmware.  It was correctly assumed that the Y2K issues would only 
be apparent at the 19991231-20000101 time boundary.

Exact times of changes are not known; noon GMT (midnight Local) was used to adequately 
window the time period of the changes.
  • PIR shaded standard deviation(pirs_sd)
  • PSP shaded standard deviation(psps_sd)
  • PSP shaded mean(psps_mean)
  • NIP mean(nip_mean)
  • PIR shaded minimum(pirs_min)
  • NIP standard deviation(nip_sd)
  • NIP maximum(nip_max)
  • PSP shaded minimum(psps_min)
  • PIR shaded maximum(pirs_max)
  • PIR shaded mean(pirs_mean)
  • NIP minimum(nip_min)
  • PSP shaded maximum(psps_max)
  • Downwelling Shortwave Diffuse Hemispheric Irradiance, Pyrgeometer, Minima(down_short_diffuse_hemisp_min)
  • Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Standard Deviation(down_long_hemisp2_std)
  • Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
  • Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Maxima(down_long_hemisp2_max)
  • Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
  • Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
  • Shortwave direct normal irradiance, pyrheliometer, minima(short_direct_normal_min)
  • Shortwave direct normal irradiance, pyrheliometer(short_direct_normal)
  • Downwelling shortwave diffuse hemispheric irradiance, pyranometer, maxima(down_short_diffuse_hemisp_max)
  • Downwelling Shortwave Diffuse Hemispheric Irradiance, Pyranometer, Standard
  • Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2(down_long_hemisp2)
  • Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Minima(down_long_hemisp2_min)

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