Networking Marine Instruments: – 06 | Marine Electronics Installation Guide

Crushing Your Fears: Marine Electronics Installation Guide

With this marine electronics installation guide, I will take you through the key steps of planning and installing your next upgrade. We’ll consider cable runs, protecting and securing cables, as well as the basic tools and equipment required. We’ll use a simple example installation consisting of a chart plotter (MFD), depth transducer, Fusion stereo, and VHF radio with DSC. This will be installed on an outboard motor-powered trailerable fishing boat.

What this article won’t cover

I will not cover details on making and waterproofing every type of connection in this article. That is for another day.

Please let me know what you would like more information on in the comments section, and remember to subscribe to updates to be notified when new articles are published. 

Why network these devices?

Just three reasons why you should take advantage of the networking capabilities built into these devices.

• Data sharing: The radio may have a built-in AIS receiver or transceiver. The AIS information can be shared with and displayed on the chart plotter. Alternatively, the VHF may require position information from the plotter so that all of the DSC functions can be used. 
• Fusion Link: Many MFDs support Fusion Link, which allows you to control the stereo from the MFD screen. How cool is that?
• Stereo mute: when the VHF is operated.

General Considerations

Let’s consider some aspects of installing electronic or electrical equipment on a boat that could apply to any job.

Cable Runs

When planning your cable runs, it’s important to consider the layout of your boat and the locations of your electronic devices. Here are some tips for effective cable runs:

• Plan the Route: Choose the best path for each cable. If you need to pass NMEA 2000 connectors through any gap, remember that it requires at least 20mm.
• Minimise Interference: Keep power cables separate from signal cables to reduce electromagnetic interference.
• Label Cables: Clearly label each cable to ensure that future maintenance is easier.

Protecting and Securing Cables

Protecting and securing your cables is crucial to prevent damage and ensure reliable operation. Most damage to wires is caused by chafing from movement and vibration. Follow these guidelines:

• Use Conduits: Run cables through conduits or protective tubing to shield them from physical damage.
• Secure Cables: Use cable ties, clamps, or adhesive mounts to secure cables along their route.
• Avoid Sharp Edges: Ensure cables cannot chafe on sharp edges that could cut or wear them.

Observing Cable Bend Radius Limits

Properly observing cable bend radius limits is crucial to maintaining signal integrity and preventing damage. Here are a couple of tips:

• Check Manufacturer Specifications: Refer to the manufacturer’s guidelines for the minimum bend radius of each cable.
• Provide Clearance: Ensure there is enough clearance around bends and behind devices to avoid exceeding the bend radius limits.

Tools and Equipment Required

• Screwdrivers: A set of screwdrivers for securing mounts and connections.
• Wire Cutters and Strippers: Essential for cutting and stripping cables to the correct length.
• Crimp tool: For crimping cable terminations. The ratchet type is the best, but expensive. This general-purpose style works well, provided you are careful.
• Multimeter: For testing electrical connections and troubleshooting issues. Get one that has a dial switch that can be set to DC voltage so that you are not messing around with pressing buttons to select DC, as many meters default to AC.
• Cable Ties and mount bases: For securing cables along their route. Bases can be fixed by screws or adhesive, or both. I recommend buying cable ties 200mm (8 inches) long and 3.2mm (1/8 inch) wide.
• Protective Tubing (conduit): To shield cables from physical damage.
• Label Maker: For labelling cables and connections.
• NMEA 2000 starter kit: This will provide a few Tee connectors, backbone cable, power cable and terminators. Equipment will usually be supplied with a Tee connector and a short drop cable.
• Marine grade power cable: You will need some two-core, stranded, tinned marine grade cable of about 1 mm² gauge. 

Never, ever, use solid core cable on a boat, or in any application subject to vibration. 

Example Installation: Chart Plotter, Depth Sounder, Fusion Stereo, and VHF Radio

Let’s walk through a simple example installation to illustrate the process:

Make a sketch

• Make a sketch of your boat showing the location of:
  • House battery
  • Starter battery
  • Battery isolation switches
  • Cable routes
  • Accessories switch panel
• Find a central location where the NMEA 2000 T connectors can be mounted. Typically, this is under or behind the dashboard.
• Mark the approximate length of the cable runs on the drawing.
• Write down a list of what you need for each circuit and connection:
  • NMEA 2000 Tees, backbone cables, drop cables, terminators, and power injector Tee.
  • Wire and terminals for the power connections.

Plan the power supply installation

• Find out where the power supply will come from. Typically, there will already be a small switch panel on the dash, connected to the house battery with circuit breakers or fuses. You need three switches for this installation, as follows.
  • Plotter and the NMEA 2000
  • Stereo
  • VHF – Arguably, it is preferable to wire the VHF directly to the battery, appropriately fused, of course. This is so that in an emergency, any person aboard, who may not be familiar with the boat, simply has to press the power switch on the VHF in order to operate it. This may be a requirement in some areas – check your local regulations.

Check the equipment manuals for fuse ratings. The VHF will need around 10A, and the NMEA 2000 network fuse must be 3A.

Safety First: Disconnect batteries before working on electrical circuits.

• Depth Transducer: Install the transducer on the transom and run the cable to the chart plotter, ensuring it is protected and secured along the route. If not in conduit, you should secure the cable at a minimum of every 400mm, and on each side of a bend.
• Chart Plotter: Mount the chart plotter at the helm and run the power and signal cables through conduits to the switch panel, transducer and network hub area.
• Fusion Stereo: Mount the stereo unit in the cabin and run the power cable, securing it with cable ties. Run the NMEA 2000 drop cable to a Tee on the backbone and run the speaker cables.
• VHF Radio: Mount the VHF radio at the helm and run the power and antenna cables through protective tubing to the battery and antenna mount.
• NMEA 2000 connections: Connect your drop cables to your NMEA 2000 backbone, see the introduction to NMEA 2000 article if you need a reminder.
• Power connections: Leave the power cables disconnected from the equipment or remove the fuses. Connect the power to the sources previously chosen. Double-check polarity everywhere that you can. Go for a short walk, then come back and re-check the polarity. Connect the equipment, insert fuses and switch on!

Post-installation checks

• Power up each device individually.
• Check device detection on the NMEA 2000 network. Check your manual for details, but the easiest way is usually to find “Sources” under the “Settings > Network” menu on the MFD.
• Check the following:
  • GPS fix – do you have good signals from the satellites; do you need to add a separate external antenna? 
  • Transducer depth – set the transducer depth offset (the measurement from the waterline to the transducer mounting location).
  • Depth reading – Check this with a sounding line.
  • VHF transmission and reception – Perform a radio check with another boat or a local, but not too local, coast station.
  • Ensure the VHF DSC self-test passes.
  • Stereo sound, speaker balance, Bluetooth pairing etc..
  • Switch panel behaviour – do the switches operate the equipment that you think they should? 

Troubleshooting Common Installation Issues

Even with careful planning and preparation, you may encounter some common installation issues. Here are some troubleshooting tips to help you resolve them:

• Power Issues: If your devices are not powering on, check the connections and ensure that the power cables are securely attached. Use a multimeter to test for voltage at the device’s power input.
• Signal Interference: This will often show as noise on some VHF channels or the fish finder display. If you experience signal interference, ensure that power cables are separated from signal cables. Check for any nearby sources of electromagnetic interference and move cables if necessary.
• Loose Connections: Loose connections can cause intermittent operation or complete failure and can be a fire risk. Double-check all connections and ensure they are tight and secure. Use cable ties and clamps to prevent cables from moving.
• Cable Damage: Inspect cables for any signs of physical damage, such as cuts or abrasions. Replace damaged cables and ensure they are properly protected with conduits or protective tubing.
• Incorrect Wiring: Verify that all cables are connected according to the manufacturer’s instructions

Maintenance Tips

• Check cables are secure and that connections are tight annually.
• Spray terminals with corrosion inhibitor.
• Update firmware regularly (MFD, VHF, Stereo, etc.).

Summary

By following these steps in this brief marine electronics installation guide, you will ensure the successful installation of your new marine electronics. More importantly, you will have a reliable setup for years to come. Proper planning and preparation will help you avoid common pitfalls and costly mistakes. A solid, neat job will add value to your boat when the time comes for the upgrade that you have in mind!

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