Raytheon 138-119, Operator'S And Service Manual

Page: 25 / 55

COMPASS
STD22
Change Over Box
138--119
19
3769DOC000002
Edition: April 06, 2005
3.3 Setting to work
There is no ON/OFF--switch at the Change Over Box.
There are no indicating elements.
The only operating element of the Change Over Box is the external Change Over Switch.
By operating the Change Over Switch the Change Over Box is switched into the desired
operation mode
NOTE!
The Change Over Box has to be set to work only with
switch position “Automatic”.
The normal mode of the Change Over Switch is the switch position “Automatic”, only in ex-
ceptional cases it should be switched to “Sys1” or “Sys 2”.
One of these exceptional cases is a non static error in the Compass system 1.
In this case an always changing error would activate a switch--over between system 1 and
system 2. By manual switching into position “system 2”, this unstable status is cancelled.
By switching ON one of the two power supplies (AC/DC--Converter 24 V DC) of the
STD22--system, the Change Over Box is set to work. Normally, both power supplies are
connected and switched ON.
After heating and settling time (see respective compass manual) of both compasses the
system is in operation.