Furuno LH-3000 - Manual (Page 14)

1. INSTALLATION
8
Floating ground
The LH-3000 has a floating ground. What this means is that the heat sink ground is floating
and will not ground batteries if they are connected to the ship’s chassis. To maintain a
floating ground:
1. Use a stereo plug when connecting a 4 ohm speaker to the external speaker plug.
Connect it as shown in the illustration below.
Do not use for battery -
use for ship's earth only
Stereo plug
2. Do not connect any of the output connectors on the rear panel to the ship’s ground.
3. SP outputs are floating and must not be connected to either battery or the rear panel.
Use a normal two conductor insulated speaker wire for the horn speaker.
Output power
The output power may be set for 30 W or 20 W, and the default settings is 30 W. For 20 W
output contact a FURUNO agent or dealer for details.
Note: If an external speaker is used it must be capable of handling the rated output power.