The SeaTalkng ® power cable (A06049) is used to connect the SeaTalkng backbone to your chosen
12 V dc power supply.
SeaTalkng ® product loading
The number of products that can be connected to a SeaTalkng ® backbone depends on the current
draw of each product and the physical length of the backbone cabling.
NMEA 2000 Load Equivalency Numbers (LEN) are used to express the amount of current that is
drawn from SeaTalkng ® products (1 LEN = 50 mA) The LEN for each product can be found in the
product’s Technical Specification.
LENs are used to determine the power connection point for the SeaTalkng ® backbone.
SeaTalkng ® power connection point
The 12 V dc power supply is connected to a spur connection on the SeaTalkng ® backbone.
Large systems
If the backbone length is greater than 60 m (197 ft), the power connection point should be connected
at a point that creates a balanced current draw from each side of the backbone. The NMEA 2000
Load Equivalency Number (LEN) is used to determine the power connection point for the backbone.
In the example above the backbone has an overall LEN of 10, so the optimum connection point would
be to have 5 LEN either side of the connection point.
Small systems
If the backbone length is 60 m (197 ft) or less, the power connection point may be connected at
any point in the backbone.
In-line fuse and thermal breaker ratings
The SeaTalkng ® network’s power supply requires an in-line fuse or thermal breaker to be fitted.
• In-line fuse rating: 5 A
• Thermal breaker rating : 3 A (refer to note below)
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