Vertex Drive System Log
as of Saturday, 05-Jul-2008 18:30:07 AST

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Name	Email	Date	Comment
Luis Murray	lmurray@naic.edu	Wednesday, February 2, 2005 10:36:08	January 6 2005, Overtemperature failure at Vertex's Shack. Both air conditioner units were off because 480VAC breaker was tripped. Bill Genter said that temperature at the Vertex's Shack was over 100 degrees Farenheit.
Luis Murray	lmurray@naic.edu	Wednesday, February 2, 2005 11:50:04	January 20 2005, Overtemperature failure at the Vertex's Shack again. The same 480VAC breaker tripped and both air conditioners were down. After the Vertex's Shack was cooled, Azimuth wasn't moving in one direction using the "traking mode". Problem was found at the PLC. Overtemperature damaged the Siemens CPU 928B PLC (Vertex's Drive's System Control Computer). Azimuth axis
Luis Murray	lmurray@naic.edu	Wednesday, February 2, 2005 11:55:44	January 22 2005, We helped Maintenance Department to check the 480VAC 20Amp breaker today. Breaker looked OK but one of the air conditioner units was drawing more than 30 Amps when starting. Starting capacitor was replaced for that AC and the breaker was replaced with a 40 Amp.
Luis Murray	lmurray@naic.edu	Wednesday, February 2, 2005 14:05:18	January 29 2005, Gregorian Dome pre-limits and final limits were at a different setting. Lower limit was around 3 degrees. After evaluation we found that the problem was at the "cam switch". It is located at the opposite side of the GD encoder and it contains the pre and final limits for both up and down limits. Our recomendation is to replace the "cam switch" with individual switches.
Luis Murray	lmurray@naic.edu	Wednesday, February 9, 2005 16:09:36	Feb 4 2005, Discrete limit switches were installed at the Gregorian Dome. These switches are replacing the "Cam Switch" wich included the pre-limits and final limits. Emergency limits were tested and are OK. Final limits are located .04 degrees after the Emergency limits and pre-limits are .04 degrees after the final limit.