Yes, the NMEA 2000 backbone cable draws power through a Power Tap. One end of the Power Tap connects to a fuse or breaker the other to a special T-Connector. Connect power as close to the center of the backbone as possible. Doing so will ensure even power distribution throughout the system.
However, the backbone cable is only able to power devices that draw up to 1 amp. Any device needing more than 1 amp of current, such as lights and audio equipment, must be wired to its own power source. Fortunately, NMEA 2000-certified devices show how much current they draw from the backbone cable on the label. The current draw is shown as a Load Equivalence Number (LEN). One LEN is equal to 50mA drawn by the device. In other words, a device drawing between 51mA and 100mA has a LEN of 2, 451mA – 500mA (.5A) a LEN of 10, and so on until it reaches 1000mA or 1 Amp.
