Garmin GMR 40, GMR 20 Installation Guide

GMR 20/40

marine radar

installation instructions

© Copyright 2004, 2005 Garmin Ltd. or its subsidiaries

Garmin International, Inc.

1200 East 151st Street,

Olathe, Kansas 66062, U.S.A.

Tel. [phone] or 800/800.1020

Fax [phone]

All rights reserved. Except as expressly provided herein, no part of this manual may be reproduced, copied, transmitted, disseminated,
downloaded or stored in any storage medium, for any purpose without the express prior written consent of Garmin. Garmin hereby grants
permission to download a single copy of this manual onto a hard drive or other electronic storage medium to be viewed and to print one copy
of this manual or of any revision hereto, provided that such electronic or printed copy of this manual must contain the complete text of this
copyright notice and provided further that any unauthorized commercial distribution of this manual or any revision hereto is strictly prohibited.

Information in this document is subject to change without notice. Garmin reserves the right to change or improve its products and to make
changes in the content without obligation to notify any person or organization of such changes or improvements. Visit the Garmin Web site
(www.garmin.com) for current updates and supplemental information concerning the use and operation of this and other Garmin products.

Garmin®, is a registered trademarks of Garmin Ltd. or its subsidiaries and may not be used without the express permission of Garmin.

Industrial Estate, Romsey, SO51 9DL,

Garmin (Europe) Ltd.

Unit 5, The Quadrangle, Abbey Park

U.K.
Tel. [phone]
Fax [phone]

Garmin Corporation

No. 68, Jangshu 2nd Road, Shijr, Taipei County,

Taiwan
Tel. [phone]
Fax [phone]

November 2005 Part Number 190-00457-02 Rev. C Printed in Taiwan

WELCOME

Thank you for choosing the Garmin GMR 20/40. The GMR 20/40 utilizes the performance of Garmin radar and provides overlay and color
information when combined with a marine Multi-Function Display (MFD).

Contact Garmin

If you should encounter any difficulty while using your GMR 20/40, or if you have any questions, in the U.S.A. contact Garmin Product
Support by phone: [phone] or 800/800-1020, Monday thru Friday, 8 am to 5 pm Central Time; or by e-mail at [e-mail]. In
Europe, contact Garmin (Europe) Ltd. at 44/0870.8501241.

Product Support Registration

Help us better support you by completing our on-line registration today! Have the serial number of your GMR 20/40 handy and connect to our
Web site (www.garmin.com). Look for the Product Registration link on the Home page. Also, be sure to record your serial number in the area
provided on this page.

Serial Number

Use this area to record the serial number in case it is lost, stolen, needs service, or if you need to contact Product Support. The 8-digit number is
located on the bottom of the unit and on the outside of the product box. It is advisable to record this number prior to installation of the scanner.
Be sure to keep your original sales receipt in a safe place or attach a photocopy inside the manual.

Serial Number:

NOTE: The Garmin GMR 20/40 has no user-serviceable parts. Should you ever encounter a problem with your unit, please take it to an authorized

Garmin NMEA dealer or contact Garmin Product Support for repairs.

Packing List

Before installing and getting started with your unit, please check to see that your package includes the following items. If any parts are

missing, please contact your Garmin dealer immediately.

Standard Package:

• GMR 20 or 40 Radar Unit

• Power/Marine Network Cable

• Installation Manual

• Mount Kit Hardware

• Grommet for Marine Cable

GMR 20/40 Radar Installation Instructions

1

Scanner Installation

The following section covers the installation and setup of the GMR 20 (2 kW) and GMR 40 (4 kW) Marine Radars. The GMR 20 and 40 only
operate with components of the Garmin Marine Network with compatible MFD (Mulit-Function Displays). See your Garmin dealer or the
Garmin web site for more details. To complete the installation, you need the appropriate fasteners, tools, and mounts. These items should be
available at most marine dealers. Always wear safety goggles, ear protection, and a dust mask when drilling, cutting, or sanding. When drilling
or cutting, always check first to see what is on the other side of the surface. If you experience difficulty with the installation, contact Garmin
Product support or seek the assistance of a professional installer.

Installation Guidelines

In order to maximize the performance of the radar, please observe the following installation guidelines:

• An ideal scanner mounting location is high above the ship’s keel line with a minimal part of the vessel’s structure or rigging blocking
the radar beam. Obstructions in the path of the radar beam may cause blind/shadow sectors or generate false echoes. The higher the
installation position, the further the scanner can detect targets.

• Avoid mounting the scanner on the same level as smoke stacks or horizontal spreaders/crosstrees on a mast. Do not install the scanner
near heat sources where it may be subjected to smoke or hot air from smoke stacks or heat from lights.

• The mounting surface/platform should be sturdy enough to support the weight of the scanner (26 lbs), flat as possible, and parallel with
the vessel’s water line.

• It is recommended that the radar scanner be mounted out of range of personnel (horizontial beam width above head height). When
the scanner is transmitting, do not look directly at the antenna at close range as your eyes are the most sensitive part of the body to
electromagnetic energy. When properly installed and operated, the use of this radar conforms to the requirements of ANSI/IEEE C95.1­1992 Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields.

• A “Compass Safe Distance” must be maintained between the compass and the scanner. The “Compass Safe Distance” is measured from
the center point of the compass to the nearest point on the scanner.

Standard compass = 1 m

Standby Steering and Emergency compasses = 0.6 m

12.5°

12.5°

Ideal Radiation Plane

Ideal Radiation Plane

12.5°

12.5°

• Mount other electronics and cables more than 2 m (7 ft) from the path of a radar beam. A radar beam can normally be assumed to spread
25° vertically above and below the scanner’s radiating element. For vessel’s with higher bow angles at cruise speed, it may be helpful to
lower the angle so the beam points slightly downwards to the waterline while at rest. Shims may be used as necessary.

• Install the scanner away from antennas for other electronics. GPS antennas should be either above or below the radar beam path of the
scanner. Mount at least 1 m (3 ft) from any equipment transmitting or cables carrying radio signals e.g. VHF radios, cables and antennas.
In the case of SSB radios, the distance should be increased to 2 m (7 ft). IEC 60936-1 clause 3-27.1 maximum distances from the antenna
at which RF (Radio Frequency) levels can be expected.

GMR20 (100W/m squared = 40 cm [15.75"]) (10W/m squared = 120 cm [47.24"])

GMR40 (100W/m squared = 60 cm [23.62"]) (10W/m squared = 175 cm [68.90"])

• The radar scanner transmits electromagnetic energy. It is important that the radar is turned off or the DC power input is disconnected
whenever personnel are required to come close to the scanner to perform work on the scanner assembly or associated equipment.

Installation

The following order of mounting the scanner and attaching the Power/Network cables may vary depending on the installation location and
mount used.

2

GMR 20/40 Radar Installation Manual

Mounting the Scanner

Ship's Bow

141.5 mm

(5.57")

233.0 mm
(9.17")

O 9.5 mm

(0.37")

1. Once 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 M8x30 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 three guide grooves moulded into the bottom of the scanner case (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 and the rounded
marks aligned towards aft (Figure 2). A bead of marine sealant may be applied around each of the mounting holes on the mounting
surface.

6. Fasten the scanner to the mounting surface using the M8x1.25x30 hex bolts, spring washers, and flat washer and shoulder washers
in the order show in Figure 3. The supplied M8x1.25x30 bolts, flat washers, and spring washers (4 each) may 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 N m (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. You may choose to apply a marine sealant after installation to weatherproof around the
grommet and cable. Additional Cable Grommets may be purchased through Garmin or your 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 in parallel other cables such as, radio antenna lines or power cables. This is essential to avoid

interference to/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 v D.C. is required at the 15 m cable

connector during radar turn-on and operation. See table below for recommended wire gauge between radar cable and battery.

Up to:

2 meters (6.5 ft) 16 AWG

4 meters (13 ft) 14 AWG

6 meters (19 ft) 12 AWG

Wire Gauge Table

Network

RJ-45 Port

Power

Connector

Mounting

Holes

Stern
Mark

Scanner

Mounting

Bracket

Shoulder

Washer

Flat

Washer

GMR 20/40 Radar Installation Instructions

Figure 1

Bow

Mark

Figure 2

Cable Guide

Grooves

Figure 3

Spring

M8x30

Bolt

3