Raymarine PowerPilot User Manual

Page 13

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

senses that

the course error has been removed.

3.3.3 Drive Unit Test Procedures

Before attempting sea trials it is important
to check that the vital link with the
steering system provided by the hydraulic

pump and rudder reference transducer
are free from obstruction and operating

correctly.

Warning
When the steering system is being moved
manually or under drive from the
autopilot do

not

touch any part of the

system. The forces exerted are
considerable and could cause injury.

With an assistant to turn the main

steering wheel get into a position where
the tiller and rudder reference transducer
can be seen.

With the autopilot in

Stand

by turn

the sheering wheel from hard over to

hard over.

Check that the rudder reference

transducer and linkage do not foul any
part of the steering mechanism or
vessel’s structure.

Select Auto and use the + 10 button

to drive the rudder hard over
maximum rudder setting).

Use the 10 button to drive the

rudder hard over in the opposite
direction.

Check that the steering ram moves

smoothly and that there is no excessive

Check that all unions are tight and

there is no seepage of hydraulic fluid.

Current Limit and Cutout
When the rudder is driven onto end stops
drive to the hydraulic pump may cut out
after a few seconds. This is normal. Drive
will only be restored if the rudder moves
away from the end stop or if drive is
required in the opposite direction.

The performance of the

will only reach the designed

levels if the installation of the hydraulic
pump and rudder reference transducer is

correctly engineered and adjusted. It is
strongly advised that these be checked

before sea trials.

4. SEA TRIALS

Initial sea trials should be carried out in

calm conditions with plenty of sea room.
The previously conducted functional test
will have verified that the autopilot is

operating correctly and that you are
familiar with all of its controls.

Set the rudder control on all control

units to minimum.

Initial sea trials on fast planing vessels

should be conducted at no more than half
engine speed. Minimum setting of the

rudder control should provide stable
steering performance.

Fine setting of the rudder control is

discussed later (4.2).

4.1 FIRST SEA TRIALS

During first sea trials, the vessel will be

changing heading, and it is,

therefore, very important to maintain a
constant look-out. The following initial
trial procedure is recommended:-

@ Steer on to a compass heading and

hold the course steady.

Press Auto to lock on to the current

heading. In calm

conditions a

perfectly constant heading will be
maintained.

Alter course to port or starboard in

multiple increments of 1 and 10
degrees from any control unit. Course
changes should be prompt and
without any sign of overshooting.

If a hand held control unit is fitted key

Manual to change over to remote
power steering. Practice power

steering using the four course control

keys..

Press Stand by to disengage the

autopilot for return to hand steering.

Automatic Sea State

Control

During the sea trial, the operation of the
automatic sea state control can be
observed. When the autopilot is initially
engaged in Auto mode the autopilot will
respond to all pitch and roll movements.

During the first minute of operation, it will
be noticed that repetitive movements of

the vessel are gradually neglected until
finally the autopilot will respond only to
true variations in course.

To ensure precise course adjustments

the sea state control is automatically reset
whenever a 1

course change is

selected.

Automatic Trim Control

The

automatically

corrects for trim. No adjustment of the

pilot is necessary.

After each course change the

Automatic Trim is cancelled and the

will re-establish the

correct trim for the new heading. This
process takes approximately one second
per degree of course change. It should be
noted that if a large course change is
keyed in (greater than

the pilot will

not assume the final selected course
immediately. The vessel will come to
within say

of the desired course and

will only settle onto course when the
Automatic Trim has been fully established.

It is recommended the following

procedure is adopted for large course

changes.

Note required new heading

Select

Stand

by and steer manually

Bring vessel onto new heading

Select Auto and let vessel settle onto

course

Bring to final course with

increments.

It is sound seamanship to make major

course changes only whilst steering
manually. In this way any obstructions or
other vessels may be cleared properly and
due account taken of the changed wind
and sea conditions

new heading

prior to engaging the pilot.