Raymarine Pathfinder Radar Scanner - Manual (Page 43)

15
Power cable
The radome radar systems are intended for use on ships’ DC power systems
operating in the range 10.7 to 32 V DC (that is, 12 V and 24 V systems; not 32 V
systems).
A 1.5 m (5 ft) power cable is supplied (with the display unit) for connecting the
ship’s DC power to the radar scanner via the display unit. Refer to the
Display Unit
Owner’s Handbook for details on connecting this cable. This section provides
details for extending the length of the power cable.
If a longer power cable run is required, use the supplied power cable to connect to
the display unit. Then use a suitable connector block to connect the free end to the
extension cable. The supplied power cable has a cross-section of 2.0 mm
2 .
Note: For vessels with 24 V power systems, the power cable may be extended by up to
20 m using a wire gauge of 1.5 mm 2 (AWG 16) or greater, irrespective of the inter-unit ca-
ble length.
For vessels with 12 V power systems , longer power cable runs may require larger
wire gauges to minimize any voltage drop in the cable. The type of scanner, type
of inter-unit cable and cable length also affect the wire gauge required for the
extension power cable.
To determine the correct supply cable size:
1. Estimate the length of cable between the ship’s main power source and the
connector block.
2. Use the followings tables (one for each scanner size) to determine, for each
inter-unit cable combination, the wire size required for that length.
For example, you might have a 24" scanner, with 20 m between the scanner and
display unit, that you plan to connect by extending the supplied 15 m heavy inter-
unit cable with a 5 m extension cable. In addition, your 12 V power supply might
be 10 m from the display unit, requiring an extension of 8.5 m. To determine the
wire gauge required for the power cable extension, refer to the table for the 24"
scanner, go to the row labelled
15 m Heavy + 5 m ext , and read across until you
come to a maximum cable length greater than 8.5 m. This is the 10 m entry, in the
column for 4.0 mm
2 wire gauge.