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Donna Donna McNamara wrote:
SBUV/2 Users,I have been asked by management to provide a list of impacts from the shutoff of N18 SBUV. Quantitative impacts are best. They have not given up on the instrument yet -- engineers are still pondering the problem.Thanks, Donna Donna McNamara wrote:SBUV2 Users,Attempts to turn on the instrument yesterday were not successful. The chopper motor remained stuck. Instrument was shut off again. Engineers will try other things, but things do not look good at this time.Donna -------- Original Message -------- Subject: NOAA 18 SBUV/2 Chopper Motor Anomaly Date: Tue, 27 May 2008 16:43:41 -0400 From: Dong.Han <Dong.Han@xxxxxxxx>To: NOAA IJPS Notification <NESDIS.IJPS-Notification@xxxxxxxx>, SystemOps LEO <SystemOps.LEO@xxxxxxxxxxxx>, Dominique Montero <Dominique.Montero@xxxxxxxxxxxx>, Michelle Baker <Michelle.Baker@xxxxxxxxxxxx>, Peter Collins <Peter.Collins@xxxxxxxxxxxx>, "Buemi, Marco" <Marco.Buemi@xxxxxxxxxxxx>, 'Abelardo Perez Albinana' <Abelardo.PerezAlbinana@xxxxxxxxxxxx>On May 22 at approximately 15:55Z, the NOAA-18 SBUV Chopper Motor Current (VCMTRI) and Chopper Motor Phase Error (VCPHZERR) began to manifest themselves anomalously reaching red high limits. As the Chopper Motor Current reaches over the red high limit, - possibly the stall current ~ 200 ma vs nominal 20 ma - the Chopper Motor Temperature (NSBUCMTR) quickly began to follow the current, reaching 50 degrees C. After the discussion through the telecon among NASA, NOAA and Ball Aerospace, on May 23 at 1614Z, the SBUV Motor Power was turned Off and remained with Motor Power Off through until May 27. Following the Anomaly Tiger Team (NASA, NOAA and Ball Aerospace) telecon, the SBUV Chopper Motor was attempted to be restarted with recommended command sequences during two consecutive passes - resetting the Grating Drive Position to Zero and Switching the Primary Encoder to Redundant back-up but the attempt to revive the Chopper Motor was to no avail, resulting in no sign of nominal movement. The results indicated where the previous Chopper Motor status was with stall current and the temperature at red high.The Tiger Team consensus was to live the SBUV Chopper Motor Off for a few days until the team come up with other alternative procedures to try.*Meantime there will be no SBUV data available.*
-- Donna P. McNamara Physical Scientist NOAA/NESDIS/OSDPD/SSD/PIB 5200 Auth Rd., Rm 510 Camp Springs MD 20746 Phone: (301)763-8142x145 Fax: (301)899-9196
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