Power Connection Considerations
Connecting the NMEA 2000® network to a power source greater than 12 Vdc may damage devices connected to the network.
You must connect the NMEA 2000 network to power through the ignition or other external switch, or it will drain the boat battery when not in use.
You should not connect an NMEA 2000 network to power in more than one place without using a power isolator in between the two network power connections.
An NMEA 2000 network must connect to a 12 Vdc power source using a dedicated NMEA 2000 power cable.
The dedicated NMEA 2000 power cable must connect to a 12 Vdc. Connecting to a 24 Vdc or any power source greater than 12 Vdc may damage the NMEA 2000 network components or devices.
The dedicated NMEA 2000 power cable should connect to the power source through the auxiliary power switch on the boat. If there is not an auxiliary power switch, or if connecting to the auxiliary power switch causes electrical interference, you must connect the power cable to the power source through an in-line switch.
The dedicated NMEA 2000 power cable must connect to the top of a T-connector, not the side.
The power cable can connect to the top of a T-connector located in the backbone of your NMEA 2000 network on either end or in the middle, depending on the length of the backbone and the power needs of the devices on the network (Power Distribution and Balance).
Some NMEA 2000 devices provide power to the NMEA 2000 network, and this may not be ideal for every NMEA 2000 design. To avoid having two power connections to the network, you can install these devices using a power isolator (Power Isolation).