COBHAM Sea Tel 9711-56 IMA C Band, Installation Manual

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Installation Troubleshooting Sea Tel 9711-56 IMA
16-2
EAR Controlled - ECCN EAR99
5. If the Ship - Heading display is different from the actual Gyro heading, access the Heading
entry menu and key in the correct heading value (refer to the operation Ship menu section).
Note the reading. After the ship has turned more than one degree, compare the new gyro
heading with the reading on the display, if it has moved in the opposite direction then
reverse connections A and B. Reset the ACU, put in the correct ship's heading again and
verify that the display reading now follows the Gyro heading.
16.1.2. 1:1 SYNCHRO
Observe the ship's heading display on the ACU. Compare its movement with that of the ship. If it
does not move at all go to step 1. If it moves but in the wrong direction (even if it does not display the
correct heading) go to step 2. If it moves in the correct direction but does not display the correct
heading go to step 3. The gyro compass connects to the R1, R2, S1, S2 and S3 terminals.
CAUTION - Electrical Shock Potentials exist on the Gyro Compass
output lines. Assure that the Gyro Compass output is turned OFF
when handling and connecting wiring to the Terminal Mounting
Strip.
1. The Ships Heading display does not change when the ship changes direction . Using a
multimeter read between R1 and R2. It should read 115 VAC. If it does not then a fuse is
blown at the gyro repeater or there is an open between the repeater and the ACU. Read
between S1 and S2, S2 and S3 and finally S3 and S1. They should all read between 0 and 90
VAC. The voltage level will change as the ship turns. If one reading is very close to 0 volts
wait until the ship has made a major change in heading and then check voltage again. If the
reading is still very low there is a problem in the line between the gyro repeater and the ACU
or a problem in the gyro repeater itself.
2. The display changes in the direction opposite of the movement of the ship . Switch the
secondary leads S1 and S2. Caution: there is 90 VAC between them! Verify that when the
ship changes direction the display shows change in the same direction. If the direction is
correct but the heading is incorrect go to step C.
3. The ship's heading display does not indicate the correct heading . If the display is off by
60, 180 or 300 degrees, this indicates that R1 and R2 are reversed. Reverse R1 and R2 and
recheck the heading display. If the display is off by 120 or 240 degrees, this indicates that
S1, S2 and S3 are in the right order but off by one place. Note their positions and carefully
move the connections one position over (S1 to S2, S2 to S3, and S3 to S1). This action will
offset the display by 120 degrees. Check if the display now reads correctly. If not move all
three leads one more time in the same direction as last time. Verify that the ship's heading
is correct.
16.1.3. 360:1 Synchro
Observe the ship's heading display on the ACU. Compare its movement with that of the ship. If it
does not move at all go to step 1. If it moves but in the wrong direction (even if it does not display the
correct heading) go to step 2. If it moves in the correct direction but does not display the correct
heading go to step 3. The gyro compass connects to the Terminal Mounting Strip on TB3- R1, R2, S1,
S2 and S3.
CAUTION - Electrical Shock Potentials exist on the Gyro Compass
output lines. Assure that the Gyro Compass output is turned OFF
when handling and connecting wiring to the Terminal Mounting
Strip.