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3.3.2 FUNCTIONAL TEST PROCEDURE
live and signalling
'Stand by mode.
that 'Auto' mode is indicated on all control
units and that the automatic heading is
displayed preceded by letter 'A'.
units noting that course displays update
correctly and that corresponding helm
movements occur.
fitted) and note that 'Manual' mode is signalled
from all control units and that course displays
indicate compass heading.
control keys of the hand held control unit and
note that corresponding incremental helm
movements occur.
l
Key 'Stand by' and check that the drive unit
clutch disengages instantly to allow manual
steering.
If the windvane
system is fitted, correct
function of the windvane
been checked during the vane head alignment
procedure.
The automatic trimming capability of the
autopilot can be observed by the following test:
Key 'Auto' followed by a IO" course change to
starboard. This effectively simulates a condition
where the need for standing helm has developed
and the vessel is not returning to course. You will
notice that an initial fixed helm movement is
applied and that after a short interval the drive unit
will continue to apply further incremental helm
movements. If left in this condition the rudder will
eventually be driven hard over. If, however, the
vessel were moving through the water, the
progressive application of additional helm would
eventually return the vessel to the correct course
with the necessary standing helm applied. Return
to course can be simulated by keying '-10' (to
return to the current heading). The progressive
application of standing helm will cease when the
Ship's
Compass
0
Ind. Cont. Unit
Deviation
controls have already
30"
60"
90"
senses that the course error has been
removed.
3.3.3 COMPASS DEVIATION CHECK
When using an indicating control unit the
any magnetic deviation errors present in the
vessel and thus may not correlate with the
headings obtained from the main steering
compass.
It is important that these errors be checked if
the heading information is to be used for
navigation or course setting purposes.
To carry out a deviation check take the
vessel into clear unobstructed water and steer
onto the following sequence of headings on the
ship's
compass.
With the Autohelm 6000 in 'Stand-by' note
the compass heading read by the indicating
control unit at 30" increments on the Table
below. Allow the vessel to stabilise on each
heading for 15 seconds before noting the
heading.
To set the fluxgate compass for minimum
deviation note the maximum errors read during
the test..
Say i-4" at Heading 060"
-2" at Heading 240"
Total deviation is 6"
Setting error is ((+4) + (-2)) = 2 = +l"
To reset fluxgate therefore rotate compass
unit so that reading increases by 1" from
previously set position.
If maximum errors were
Say-4" at Heading 060"
-10" at Heading 240"
Total deviation is 6"
Setting error is ((-10) + (-4)) = -14 = -7"
To reset fluxgate rotate compass unit so that
reading decreases by 7" from previously set
position.
After adjustment repeat the deviation check
and note the deviation figures for reference.
150"
210"
240"
2
2
2
270"
300"
330"
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