Sperry Marine Rudder Angle Indicator System, Руководство по эксплуатации, установке и обслуживанию

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056357/B RAIS
6-24 In- and Output Calibration
Input Calibration using Dummy Values
In some installations, it may be required to carry out the output calibra-
tion before the input calibration. E. g., if the RAI system is installed and
wired up, but the rudder cannot be actuated because the steering gear is
not operational. As a temporary measure in such cases, the input may
be calibrated using the feedback potentiometer supply and center tap
potentials as input signals, instead of the actual feedback signal.
To calibrate the input using dummy values:
1. Disconnect the feedback unit from the RAC, TB 1.3 through 1.6
(refer to circuit diagram 5014-0115-01).
2. Proceed as if carrying out the initial input calibration (see “Initial
Calibration” on page 6-16).
However, instead of putting the rudder to the hardover and midships
positions,
– shorten TB 1.4 to 1.5 to connect the negative feedback supply
potential to the input. Then, enter the nominal hardover port
angle (e. g. -45 or -70 degrees) in the rudder angle control and
click to set the hardover port calibration point;
– shorten TB 1.4 to 1.6 to connect the feedback center tap potential
to the input. Then, enter a value of 0.0 degrees in the rudder
angle control and click to set the midships calibra-
tion point;
– shorten TB 1.4 to 1.3 to connect the positive feedback supply
potential to the input. Then, enter the nominal hardover star-
board angle (e. g. 45 or 70 degrees) in the rudder angle control
and click to set the hardover starboard calibration
point.
3. Re-connect the feedback unit to the RAC, TB 1.3 through 1.6.