ACU-150
15 A
ACU-200
20 A
ACU-300
15 A
ACU-400
40 A
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
2
(#10 AWG) or
greater.
• for runs of >1m (3 ft), use 8 mm
2
(#8 AWG) or
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
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.
Important:
When planning and wiring, take into consideration
other products in your system, some of which (e.g.
sonar modules) may place large power demand
peaks on the vessel’s electrical system.
Note:
The information provided below is for guidance
only, to help protect your product. It covers
common vessel power arrangements, but does
NOT cover every scenario. If you are unsure how
to provide the correct level of protection, please
consult an authorized Raymarine dealer or a
suitably qualified professional marine electrician.
Implementation — direct connection to battery
• The unit may be connected directly to the vessel's
battery, via a suitably rated fuse or breaker.
• If the unit does not require a separate RF Ground
(drain) connection, only the power cable’s red and
black wires need to be connected.
• You MUST fit a suitably rated fuse or breaker
between the red wire and the battery’s positive
terminal.
• Refer to the inline fuse ratings provided in the
product’s documentation.
A
Battery connection scenario A: suitable for a vessel
with a common RF ground point. In this scenario, if
your product requires a separate RF Ground (drain)
connection then it should be connected to the vessel’s
common ground point.
B
Battery connection scenario B: suitable for a vessel
without a common grounding point. In this case, if
your product requires a separate RF Ground (drain)
connection then it should be connected directly to the
battery’s negative terminal.
Implementation — connection to distribution
panel
30