Grounding - Dedicated Drain Wire Required; Power Distribution - Acu - Raymarine EVOLUTION EV-1 Installation Instructions Manual

Warning: Positive ground
systems
Do not connect this unit to a system which
has positive grounding.
Fuses and circuit protection
There are 3 levels of power protection in the autopilot
system. The drive (motor) and associated cables
are initially protected by the current sensing and stall
condition detection within the ACU hardware and
software. A second level of protection is provided
to these parts and the ACU components by the
unit's main power fuse. Protection for the entire
autopilot system and its wiring back to the main
power distribution panel is provided by your vessel's
circuit breaker / fuse.
Power supply circuit protection
Protect the power supply for the Evolution system at
the distribution board with a fuse or circuit breaker
that is suitable for the ACU. For guidance, refer to
main power fuse rating stated on the ACU connector
panel. If in doubt, consult your local dealer.
Internal fuses
The ACU uses standard automotive blade fuses.
Spare fuses are located on the underside of the
removable cover.
Note:
For clarity, only the power and fuse-related
connections are shown in the illustration above.
1. Power fuse (accessible via the removable cover)
2. SeaTalkng® fuse (fuse power supply from ACU
to SeaTalkng® backbone)
3. Power fuse (labelled with total power consumed
by system)
Fuse ratings
SeaTalkng®
ACU-100
ACU-150
Cables and connections
3 A
10 A
15 A
ACU-200
ACU-300
ACU-400
Grounding — Dedicated drain wire
required
This product includes a dedicated drain conductor
(screen) for connection to a vessel's RF ground
point.
It is important that an effective RF ground is
connected to the unit. The unit can be grounded
by connecting the drain conductor (screen) to the
vessel's RF ground point. On vessels without an
RF ground system the drain conductor (screen)
should be connected directly to the negative battery
terminal.
The dc power system should be either:
• Negative grounded, with the negative battery
terminal connected to the vessel's ground; or
• Floating, with neither battery terminal connected
to the vessel's ground.
If several items require grounding, they may first
be connected to a single local point (e.g. within
a switch panel), with this point connected via a
single, appropriately-rated conductor, to the vessel's
common RF ground point.
Implementation
The preferred minimum requirement for the path to
ground is via a flat tinned copper braid, with a 30A
rating (1/4inch) or greater. If this is not possible, an
equivalent stranded wire conductor maybe used,
rated as follows:
• for runs of <1m (3 ft), use 6mm
greater.
• for runs of >1m (3 ft), use 8 mm
greater.
In any grounding system, always keep the length of
connecting braid or wires as short as possible.
References
• ISO10133/13297
• BMEA code of practice
• NMEA 0400
Power distribution — ACU
Recommendations and best practice.
• The product is NOT supplied with a power cable.
Please refer to the Power and drive cables
section for power cable requirements.
• Refer to the Power connection section for more
information on how to identify the wires in your
product's power cable, and where to connect them.
• See below for more information on implementation
for some common power distribution scenarios.
20 A
15 A
40 A
2 (#10 AWG) or
2 (#8 AWG) or
35