Lowrance electronic LMS-339cDF iGPS GPS Receiver User Manual


 
31
Powering the Unit
(Power Supply cable – red and black wires)
The unit works from a 12-volt battery system. For the best results, at-
tach the unit power cable directly to the battery. You can attach the
power cable to an accessory or power buss, but you may have problems
with electrical interference. Therefore, it's safer to go ahead and attach
the power cable directly to the battery.
CAUTION:
When using the unit in a saltwater environment, we strongly rec-
ommend that you shut off the power supply to the unit power cable
when the unit is not in use. When the unit is turned off but still
connected to a power supply, electrolysis can occur in the power ca-
ble plug. This may result in corrosion of the plug body along with
the electrical contacts in the cable and the unit's power socket.
In saltwater environments we recommend you connect the unit
power cable to the auxiliary power switch included in most boat
designs. If that results in electrical interference, or if such a
switch is not available, we recommend connecting direct to the
battery and installing an inline switch. This will let you shut off
power to the power cable when the unit is not in use. When you
are not using the unit, you should always shut off power to the
power cable, especially when the power cable is disconnected from
the unit.
If possible, keep the power cable away from other boat wiring, especially
the engine's wires. This will provide the best isolation from electrical
noise. If the cable is not long enough, splice #18 gauge wire onto it.
The power cable has two wires, red and black. Red is the positive lead,
black is negative or ground. (There is also a white wire to power an op-
tional external speaker for some units.) Make sure to attach the in-line
fuse holder to the red lead as close to the power source as possible.
For example, if you have to extend the power cable to the battery or
power buss, attach one end of the fuse holder directly to the battery or
power buss. This will protect both the unit and the power cable in the
event of a short. It uses a 3-amp fuse.