Specifications

Doc Number: VIS-ANA-VER-01001-9002
Date: 27 May 2004
Issue: 5.0
Page: 28 of 80
Author: J. Delgadillo
Controls Preliminary Design Report Issue 5.doc
4.2.4.8 AZ/ALT Interlocking
As dictated by AD01 11.1.7 c spec, if any of the following isolated contacts open, 3-phase
power is removed from the azimuth and/or altitude motor controllers, and will independently
remove the brake release command.
The Azimuth axis is composed of the following interlock chain:
Emergency Stops (AZ Motor 1-2, AZ Motor 3-4, Alt Motor 1, Alt Motor 2, Alt Pier,
Equipment Room, and Cone E-stops)
AZ Positive/Negative Interlock Limit
AZ Stow Pin Engaged
AZ Overhead Dome Crane Interlock (AD01 13.4.12 b spec)
Yoke Access Hatch Interlock
AZ LCU Interlock
Pier Access Interlock
Mobile Access Platform Interlock
The Altitude axis is composed of the following interlock chain:
ALT Overspeed
Emergency Stops (AZ Motor 1-2, AZ Motor 3-4, ALT Motor 1, ALT Motor 2, ALT
Pier, Equipment Room, and Cone E-stops)
ALT Positive/Negative Interlock Limit
ALT Stow Pin Engaged
ALT Auxiliary Drive Enabled Interlock (AD01 11.1.12 spec)
ALT Overhead Dome Crane Interlock (AD01 13.4.12 b spec)
ALT LCU Interlock
OSS Not Installed
CASS Instrument not Installed
M2 Unit not Installed
M1 Mirror Restraint Failure
Mobile Access Platform Interlock
AZ Floor Access Interlock
Per the requirements of AD07, the LCU should have the capability to turn ON and OFF
power to the motor controllers. VertexRSI will partially comply with this requirement. It
will be possible for the LCUs to remove power to the motor controllers by issuing an
Interlock command, but when power needs to be restored (after clearing the fault condition),
it would need to be done by manually turning on the tripped circuit breakers in the Power
Drive Unit. By having the operator physically switching back ON the circuit breakers that
tripped, it ensures that the operator is made aware of the problem that caused the
Interlock chain to break so that the appropriate remedial action can be made in order to avoid
the situation again. This is in line with VertexRSI’s safety philosophy where software should
not be allowed to clear a hardware condition. Furthermore, the design of the motor controller