Garmin GHP 20 Marine Autopilot System for Steer-by-Wire, Installation Instructions Manual

Page: 13 / 257

2
Disconnect one side of a NMEA 2000 T-connector from the
network.
3
If necessary, to extend the NMEA 2000 network backbone,
connect a NMEA 2000 backbone extension cable (not
included) to the side of the disconnected T-connector.
4
Add the included T
‑
connector
Â
for the CCU to the NMEA
2000 backbone by connecting it to the side of the
disconnected T
‑
connector or backbone extension cable.
5
Route the included drop cable
Ã
to the CCU and to the
bottom of the T-connector added in step 4.
If the included drop cable is not long enough, you can use a
drop cable up to 20 ft. (6 m) long (not included).
6
Connect the drop cable to the CCU and the T-connector.
Connecting Optional Devices to the Autopilot System
You can use advanced features of the autopilot system by
connecting optional NMEA 2000-compatible devices, such as a
wind sensor, a water-speed sensor, or a GPS device to the
NMEA 2000 network.
You can connect optional devices that are not NMEA 2000
compatible to the helm control through NMEA 0183 ( page 13 ).
1
Add an additional T-connector (not included) to the NMEA
2000 network.
2 Connect the device to the T-connector by following the
instructions provided with the device.
NMEA 0183 Connection Considerations
• The installation instructions provided with your NMEA 0183-
compatible device should contain the information you need
to identify the transmitting (Tx) and receiving (Rx) A (+) and
B (-) wires.
• When connecting NMEA 0183 devices with two transmitting
and two receiving wires, it is not necessary for the NMEA
2000 bus and the NMEA 0183 device to connect to a
common ground.
• When connecting a NMEA 0183 device with only one
transmitting (Tx) wire or with only one receiving (Rx) wire,
the NMEA 2000 bus and the NMEA 0183 device must be
connected to a common ground.
Pump Installation
Mounting the Pump
Before you mount the pump, if your boat has an unbalanced
cylinder steering system, you must re-configure the pump to
work properly with the unbalanced cylinder ( page 2 ).
Before you can mount the pump, you must select a location
( page 2 ) and determine the correct mounting hardware
( page 1 ).
1
Hold the pump in the intended mounting location and mark
the locations of the mounting holes on the mounting surface,
using the pump as a template.
2
Using a drill bit appropriate for the mounting surface and
selected mounting hardware, drill the four holes through the
mounting surface.
3
Secure the pump to the mounting surface using the selected
mounting hardware.
Connecting the Hydraulic Lines to the Pump
Refer to the layout diagrams beginning on page 7 for
assistance.
1
Disconnect the necessary lines from the hydraulic system.
2
Add a T-connector to the starboard and port lines of the
system between the helm and the steering cylinder.
NOTE: If the boat has a power-assist module, add the T-
connectors between the power-assist module and the
steering cylinder.
3
Complete an action:
• If the boat does not have a power-assist module, add
enough hydraulic hose to connect the return fitting on the
helm to the pump fitting labeled with a T.
• If the boat has a power-assist module, a return line should
already exist between the helm and the power-assist
module. Add a T-connector to the return line of the
system between the power-assist module and the helm.
4
Add hydraulic hose to the unused fitting on each T-
connector, with enough hose to connect the T-connector to
the pump fittings.
5
Connect the starboard line T-connector to a pump fitting
labeled with a C1 or C2.
6
Connect the port line T-connector to the pump fitting labeled
with a C1 or C2 that you did not use in step 4.
7
Complete an action:
• If the boat does not have a power-assist module, connect
the return fitting on the helm to the pump fitting labeled
with a T.
• If the boat has a power-assist module, connect the return
line T-connector to the pump fitting labeled with a T.
8
Install the Shadow Drive in the port or starboard hydraulic
line between the helm and the T-connector ( page 12 ).
9
Install a shut-off valve (not included) on each hydraulic line
that connects directly to the pump.
10
Insert, tighten, and seal the included plugs in the unused
pump fittings, if they are not already in place.
Connecting the Pump to Power
WARNING
When connecting the power cable, do not remove the in-line
fuse holder. To prevent the possibility of injury or product
damage caused by fire or overheating, the appropriate fuse
must be in place as indicated in the product specifications. In
addition, connecting the power cable without the appropriate
fuse in place will void the product warranty.
You should connect the pump power cable directly to the boat
battery, if possible. Although it is not recommended, if you
connect the power cable to a terminal block or other source,
connect it through a 40 A fuse.
If you plan to route the pump through a breaker or a switch near
the helm, you should use an appropriately sized relay and
control wire. Do not extend the pump power cable in this case.
1 Route the connector-terminated end of the power cable to
the pump, but do not connect it to the pump.
2
Route the bare-wire end of the power cable to the boat
battery.
13