Raymarine Autohelm 5000 User Manual page 13

2.2.3 HYDRAULIC DRIVE UNIT
The hydraulic drive unitshould be mounted
clear of spraj/ and the possibility of immersion
in water. It should be located as near as
possible to the hydraulic steering cylinder. It is
important to bolt the hydraulic drive unit
securely to a substantial member to avoid any
possibility of vibration that could damage the
inter-connecting pipework.
The drive amplifier (Fig. 13) should be
mounted between the drive unit and the power
supply (batteries) in order to minimise the total
length of power cable. It should also be
mounted in a position clear of bilge water and
spray. The drive amplifier is mounted by first
removing the cover marked 'Autohelm' and
bolting or screwing to a suitable vertical
bulkhead through the four holes in the .base
(Fig. 14).
There are three basic types of hydraulic
steering system (Fig. 12). Typical connection
points for the drive unit are shown in each case.
In all cases it is strongly recommended that
the steering gear manufacturer be
consulted. The drive unit valve block is tapped
Dowty sealing washers are supplied (Fig. 15).
Two Line System
CONTROL
I
EARTHING
Two Line
Pressurised System
-RESERVOIR LINE
222mm (8 7")
Fig. 13 Drive Amplifier
UNIT POWER SUPPLY CABLE
SOCKET
TERMINAL
Diagram
Fig. 14 Drive Amplifier Wiring
Three Line System
RESERVOIR LINE
I
-ve
DRIVE UNIT
CONNECTION
.