Raymarine autopilot ST4000+, Service Manual

Page: 13 / 34

Chapter 2. Fluxgate Compass Transducer
Autopilots Service Manual 83115-1 9
Chapter 2. Fluxgate Compass Transducer
2.1 Functional test
Disconnect the Fluxgate from the Autopilot and check continuity as follows:
Cable colour Connector pin number Resistance
Screen to blue 2/4 < 10 ohms
Red to green 3/5 < 5 ohms
Red to yellow 3/6 < 5 ohms
Red to screen 3/2 Open circuit
2.2 Magnetic deviation
The Fluxgate Compass requires careful siting if optimum Autopilot
performance is to be acheived. The SeaTalk electronics is able to correct the
compass for most deviating magnetic fields present when the linearisation
procedure is carried out. Any further deviation, introduced after linearisation,
will introduce an error between the Fluxgate and the ship’s compass. This
can be removed by carrying out the linearisation again. If the displayed
deviation is greater than +/– 15 degrees the Fluxgate should be resited.
Note: The linearisation procedure should always be carried out if the
Fluxgate has been exchanged, removed or moved from its original mounting
position.