Raymarine RSW-Wired, Руководство по установке

Страница: 32 / 74

Products which have a dedicated power supply connection that are
connected to the SeaTalkng ® backbone will still have an LEN rating. This is
because product’s SeaTalkng ®/NMEA 2000 internal transceiver will still be
powered by the SeaTalkng ® backbone.
LENs are used to determine the power connection point for the SeaTalkng ®
backbone.
9.4 SeaTalkng ® power connection point
The point along the backbone where the power connection should be made
is based on the length of the backbone.
Note:
• The power connection must be connected to a white spur connection on
the backbone.
• Do NOT connect the power connection to a blue backbone connector.
• Excluding the iTC-5, do NOT connect the power connection directly to
a product’s white spur connector.
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.
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 Load Equivalency Number (LEN) is used
to determine the power connection point for the system.
In the example above the system has an overall LEN of 16, so the optimum
connection point would be to have 8 LEN either side of the connection point.
9.5 SeaTalkng ® system loading
The maximum loading / LEN for a SeaTalkng ® system depends on the length
of the backbone.
Unbalanced system loading:
• Backbone Length : 0 m (0 ft) to 20 m (66 ft) — Maximum LEN : 40
• Backbone Length : > 20 m (66 ft) to 40 m (131 ft) — Maximum LEN : 20
• Backbone Length : > 40 m (131 ft) to 60 m (197 ft) — Maximum LEN : 14
Balanced system loading:
• Backbone Length : 0 m (0 ft) to 60 m (197 ft) — Maximum LEN : 100
• Backbone Length : > 60 m (197 ft) to 80 m (262 ft) — Maximum LEN : 84
• Backbone Length : > 80 m (262 ft) to 100 m (328 ft) — Maximum LEN : 60
• Backbone Length : > 100 m (328 ft) to 120 m (394 ft) — Maximum LEN : 50
32