Furuno GP-31, Operator'S Manual

Page: 60 / 81

9-2
Grounding
The display unit contains a CPU. While it is
operating, it radiates noise, which can in-
terfere with radio equipment. Ground the
unit as follows to prevent interference:
• The ground wire should be 1.25sq or
larger.
• The ground wire should be as short as
possible.
• The signal ground and frame ground are
separated, however the power line is not
isolated. Therefore, do not connect the
signal ground to the frame ground when
connecting other equipment to a posi-
tive ground battery.
• The antenna unit GPA-018 (for GP-36)
must be grounded. Connect a ground
wire of 1.25sq or larger (local supply)
between the ground terminal on the an-
tenna unit and a stainless steel screw
fastened to the mast. Coat the ground
terminal, stainless steel screw and crimp-
on lug on the ground wire with silicone
sealant.
• The power of this equipment is not iso-
lated, thus the earth lamp may light when
the antenna unit GPA-018 is grounded.
If it lights, attach two capacitors (1
m
F,
0.1
m
F) in parallel to the antenna earth
line.
External equipment
The power supply port is commonly used
for connection of external equipment such
as navigation equipment or a PC. Refer to
the interconnection diagram on page S-1
or S-2 for connection.
9.3 Wiring
The figure below shows where to connect
cables on the rear of the display unit. Please
review the WARNING SHEET at the front
of this manual before wiring the equipment.
Black Red
POWER
(10.8-31.2 VDC)
Ground
1A FUSE
(+ Line)
ANTENNA UNIT
(Shown: GPA-018)
GPS ANT
DISPLAY
UNIT
+
-
Ground the equipment to
prevent mutual interference.
CAUTION
Figure 9-3 Wiring
Note: The fuse holder contains a spring
which fixes the fuse. To prevent detachment
of the spring, which would cause loss of
power, tie the line as shown in Figure 9-4.
Fuse holder
+ line (red)
Tie here.
Figure 9-4 How to fix spring in fuse holder