Si-tex SP38, Installation And Operation Manual, Page: 47 / 193

Sitex SP38 Installation and Operation
Document PN 29010101 V1r0
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Mounting
The sensor can be mounted to the bottom of the compass using the brass screw supplied, or it
may be bonded directly to the compass bowl using a suitable adhesive. The nylon washer
should be placed between the Compass Sensor and the bottom of the compass bowl.
When the sensor mounts to the bottom of the bowl, the magnetic compass may be used as a
steering compass, if desired.
It is also possible to mount the sensor above the compass. This reduces the possibility of
interference from the compensating magnets, but also reduces the visibility of the compass.
Optimum positioning of the sensor can only be accomplished once the Autopilot system has
been installed and powered up.
See the Getting Started chapter of the manual to perform this procedure.
Electrical Connections
Route the Magnetic Compass Sensor cable from the Compass to the location where the SPU
will be. Avoid running the cable parallel to antenna cables, AC power, or DC wires/cables
carrying heavy current.
Ensure that there is sufficient slack in the cable to allow the compass bowl to tilt and rotate
freely in all directions.
Excess cable should be coiled up (Sitex recommends that the cable NOT be shortened). If the
cable is too short, plug-in Compass Extension Cables are available in various lengths from your
Sitex Dealer. Cutting and splicing the Magnetic Sensor cable is NOT recommended.
See the Compasses section for further details on connecting the cable to the SPU.
Rudder Follower
The Rudder Follower is used to transmit the position of the rudder back to the Autopilot. It
should be connected to whatever parts of the steering system the Autopilot controls.
Normally, this will be the vessel’s rudder. However, if the vessel has a two-stage steering
system where the Autopilot drives a control or servo ram, the Rudder Follower should be
mounted to the servo ram rather than to the rudder.
Normally the Rudder Follower is mounted in the stern of the vessel, close to the rudder post.
A mounting base may have to be fabricated to position the Rudder Follower properly. Mount the
Rudder Follower in a location where the possibility of damage from any equipment stowed in the
area is minimized.
Note: If you are connecting the SP38 to a mechanical Cable Drive (for vessels that use cable
steering instead of hydraulic steering), the rudder follower is built into the Cable Drive. See the
Cable Drive Installation Manual for details.