Raymarine Autohelm 4000, User Manual

Auto-Tack Function

The following additional trial is

recommended:

l 

Steer onto a constant heading

approximately 

 free of close hauled

l 

Press 

Auto 

to lock onto the current

heading or both red keys to lock onto

the apparent wind if a vane is fitted.

l 

Decrease the apparent wind angle

(using the + 1 key if on the starboard
tack) until the yacht is sailing close

hauled at optimum penetration.

l 

Prepare to tack and then press the + 1

and + 10 keys together (if on the
starboard tack) to initiate a tack to
starboard.

 The yacht will complete a 1 

 course

change to bring it onto the opposite
tack.

WIND

On 

 the tack and havinu

sheeted and retrimmed the sails, 
vessel may be brought onto the desired
apparent wind angle by fine adjustments
to the course using the + 

 1   keys. No

adjustments should be made within 1

minute of completing the tack to allow
the Autopilot to compensate for the helm
trim on the new tack.

Disengagement

When manual override is required the
drive unit can be rapidly disengaged by
operating the clutch lever.

OFF-COURSE ALARM

When the autopilot is set to either 

Auto

or 

Vane 

mode a built in off-course alarm

is automatically set up. The off-course
alarm will sound when the vessel deviates

r any reason from the original course by

‘ore than 15 degrees for over 20

seconds. It is denoted by a continuous
series of bleep tones.

The alarm will be silenced-if the vessel

returns to within 15 degrees of the
original course.

In 

Auto, 

if the vessel does not return

within these limits the alarm 

 be

silenced by selecting 

Standby.

In 

Vane, 

the alarm will sound when the

wind direction changes by more than 15
degrees and may be accepted by pressing

both red keys together. This will silence
the alarm and advance the off course
alarm datum to the current compass
heading.

CURRENT LIMITING AND CUTOUT

If the autopilot is driven into its end stops,
the drive will be 

pulsed 

to prevent

overloading the motor. If the pilot is left in
this condition for 30 seconds the
microprocessor will automatically cut out

power to the motor and sound the alarm

continuously.

To restore the autopilot for normal

operation the 

standby 

key must be

pressed to put the unit in 

standby

 mode.

! ’

 EEL BRAKE

t any time when not underway, the

wheel drive unit clutch may be engaged
to provide a wheel brake.

Rudder Control Adjustment

The rudder control setting recommended

on page 17 will provide stable control for
initial sea trials. However, sailing craft can
vary widely in their response to the helm
and further adjustment of the rudder
control setting may improve the
Autohelms steering characteristics.

An excessively high rudder control

setting results in 

oversteer 

which can be

recognised by the vessel swinging slowly
from side to side of the automatic

heading accompanied by excessive rudder
movement. In addition, distinct overshoot

will be observed when the course is

changed. This condition can be corrected
by reducing the rudder control setting
(rotating rudder control anti-clockwise).

Similarly, an insufficient rudder control

setting results in 

understeer 

which gives

sluggish steering performance and is
particularly apparent when changing
course. This is corrected by increasing the

rudder control setting (rotating rudder

control clockwise). These tendencies are

most easily recognised in calm sea
conditions where wave action does not
mask basic steering performance. The

rudder control setting is not over critical
and should be set to the lowest setting

consistent with accurate course keeping.
This will minimise actuator movements
and hence reduce power consumption.

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