Seiwa SW AP01 - Manual (Page 33)

To minimise the risk of radio interference, the Controller cable, like the others, must be
kept well separated from antennas and antenna feeds. On some vessels this is
difficult to do, but some extra effort to maintain separation will reduce problems in the
future.
3.3 COMPASS
The performance of the compass affects the performance of the whole system and
some care should be taken in locating it in the best position. If a compass slave,
mounted on the glass face of the ship’s flat top compass, is being used, performance
is mainly dictated by the accuracy of the ship’s compass.
Ideally, the compass should be mounted at the roll centre of the vessel, at or slightly
above the waterline. The unit may be damaged by long-term exposure to water and
must be above the bilge level. It should be at least 1 metre away from the engine and
from other objects with strong magnetic fields such as loudspeakers and wiring which
carry large currents. In timber, fibreglass or aluminium hulls, these conditions should
be easily met. But in steel hulls, some trial and error may be needed to find the best
position. Generally, the compass will not perform well if totally enclosed in a steel
structure. Further notes on mounting in a steel vessel are given below.
Mount the S81.02 compass on a vertical surface with its mounting flange towards the
bow and the cable entry facing down. (The compass will not operate correctly if
mounted upside down.) Corrections for small errors in orientation can be made via the
heading adjust menu option in the autopilot. Lay the cable back to the Junction Box,
following the same method and precautions as for the controller cable and terminate it
in the Compass socket as shown in Fig 3.5.
The S81.02 cable has 6 conductors, plus a screen. Five of these are connected to the
Compass socket, as in Fig 3.5(a). The sixth (brown) is connected to the brown pin on
the Gyro/Port B socket.
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