Garmin GMR 21/41 - Manual (Page 5)

GMR 21/41 Marine Radar Installation Instructions 3
Installation
The following order of mounting the scanner and attaching the Power/Network cables may vary depending on the installation location and
mount used.
Mounting the Scanner
1. When a suitable mounting location has been determined, verify that the mounting hole locations are aligned fore and aft, then drill four
9.5 mm (0.37") mounting holes referencing Figure 1 below. (This step is not necessary if you are using a pre-drilled Garmin compatible
or Raymarine ® mount.)
2. Remove the supplied M8 x 30 bolts, flat washers, and spring washers (4 each) from the bottom of the scanner unit. DO NOT remove the
outer case bolts. There are no user serviceable parts in the scanner and opening the case may void your warranty.
3. Align the notch and locking ring on the power cable to the power connector. Press the 2-pin power cable to the power connector and the
RJ-45 marine network cable to the RJ-45 socket (Figure 2). Turn the power cable locking ring clockwise until it stops. Tighten the RJ-45
locking ring clockwise until it is firmly sealed.
4. The power/network cable may be pressed into one of the five guide grooves molded into the bottom of the scanner case and secured
under the cable hold-down plate (Figure 2). Avoid excessive bending or twisting of the cable. See the following “Cable Runs” section for
more information.
5. Position the scanner on the mounting surface with the triangular marks on the case aligned to the front of the vessel. Apply a bead of
marine sealant around each of the mounting holes on the mounting surface.
6. Fasten the scanner to the mounting surface using the M8 x1.25 x 30 hex bolts, spring washers, and flat washer and shoulder washers in
the order show in Figure 3. The supplied M8 x 1.25 x 30 bolts can be used on mounting thicknesses of 5-10 mm (3/8") (recommended).
For surfaces over 10 mm (3/8"), locally supplied longer bolts are needed. The bolts should be torqued to between 13.7-18.6 Nm (10-
14 lb ft).
Cable Runs
Route the cable as needed, depending on the type of mount you are using. DO NOT cut the cable! It may be necessary to drill a 31.7 mm
(1.25") hole for routing the power/network cable. Garmin provides a rubber cable grommet which may be used to cover the cable installation
hole. The grommet does NOT provide a waterproof seal. To waterproof the grommet, apply a marine sealant. Additional cable grommets can be
purchased through Garmin or a Garmin dealer.
When installing the power/network cable, observe the following:
• To ensure safety, use the appropriate tie-wraps, fasteners, and sealant to secure the cable along a route and through any bulkhead or deck.
Avoid running the cable near moving objects, high-heat sources, or through doorways and bilges.
• Avoid installing the cable next to or parallel to other cables, such as radio antenna lines, or power cables. This is essential to avoid
interference to or from other equipment. If this is not possible, shield the cable with metal conduit or a form of EMI shielding.
• Install the power portion of the cable as close to the battery source as possible. A minimum of 10 VDC. is required at the 15 m cable
connector during radar turn-on and operation. See the table below for the recommended wire gauge between radar cable and battery.
Ship's Bow
141.5 mm
(5.57")
233.0 mm
(9.17")
9.5 mm
(0.37")
Figure 3
Mounting
Bracket
Flat
Washer
Spring
Washer
M8 x 30
Bolt
Figure 2
Mounting
Holes
Power
Connector
Network
RJ-45 Port
Figure 1
Wire Gauge Table
Distance Gauge
2 meters (6.5 ft) 16 AWG
4 meters (13 ft) 14 AWG
6 meters (19 ft) 12 AWG
Shoulder
Washer
Scanner
Cable Routing
Options
Plate