| Version |
$Revision: 1.3 $ |
| Last Update |
$Date: 2001/11/08 14:46:10 $ |
| HRC CCB Status |
NA |
Number: HRC-C-011
Type: Constraint
Original Date: 1998 October 13
Subsystem: HRC
Subject: HRC Power Internal Configuration
Source: Gerry Austin
CRL Statement:
The HRC power internal configuration must be established and verified
prior to application of 28V power by either one of the spacecraft buses.
CRL Rationale/Justification:
The power configuration constraint is derived from the HRC design.
CRL Impact:
There are two sources of damage if the HRC internal power
configuration is not established and verified prior to the application
of 28V power:
- If any of the failsafe relays have been enabled, one or more
failsafes may be initiated upon the application of the 28V. There is
no recovery possible once a failsafe has been exercised.
- Switching of the two low voltage power supplies or the four HV
power supplies from one bus to the other with 28V power applied to the
HRC will result in hot switching of the relays with the possibility of
damage or degradation.
Recommended Action:
Incorporate into the Systems and Operations Procedures, with ASC providing
the inputs.
$Log: hrc-c-011.html,v $
Revision 1.3 2001/11/08 14:46:10 juda
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Revision 1.2 1999/01/26 18:34:38 juda
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Revision 1.1 1998/10/14 13:48:59 juda
Initial revision
Dr. Michael
Juda
Harvard-Smithsonian Center for Astrophysics
60 Garden Street, Mail Stop 70
Cambridge, MA 02138, USA
Ph.: (617) 495-7062
Fax: (617) 495-7356
E-mail: mjuda@cfa.harvard.edu