IBEX 2012 Training Troubleshooting Marine Electronics

Installation Problems

Instructor- John Barry Technical Marine Support Inc.

Please turn off cell phones. Thank You

More Information www.nmea.org 410-975-9425

© 2012 NMEA

Preventative Measures

• “If you don’t have time to do it right, how will you have time to do it over?”

• NMEA V0400 Installation Standards are the definitive industry document on the proper installation of marine electronics across a variety of disciplines and applications

Stick with the Basics

• Use your eyes, close visual inspection is imperative

• Harsh environments such as bilges and engine rooms are likely places of failure

• Consider all information available, service history and failure description

• Get Technical Support, Be prepared to supply accurate information

• Always confirm symptom before starting

Troubleshooting Techniques

• Reduce network to simplest terms

• Establish a duplicatable baseline

• Change one variable at a time

• Divide and conquer

• Get service history

• Sherlock Holmes vs. Albert Einstein

Scientific Methodology

• Process of Elimination

• Scientific Method

• Tenacity, Stuck in Neutral, Be Open Minded

• Authority, Too Smart to be Wrong

• Logic and Reasonableness, not always true

• Your Methods and Measurements may be Flawed

The Wiggle Test • Hold down tightness is not enough

• Always physically test connections for integrity

• Connectors can jam in a position the does not allow electrical continuity

• No more than 2 ring terminals should be stacked

• Rotational force applied under screw hold down point

• Linear force applied to captive connectors

Dynamic Voltage Test

• Device Supply Voltage should be tested during operation

• Continuos monitoring of supply voltage during all modes of operation

• Should be measured at the device

• Transmit radios and radar, operate sonars, operate motors

• Operate vessel underway for vibration testing

• Operate devices from all power sources

• Charge batteries and run generator for noise testing

• Operate related devices to confirm compatibility

Troubleshooting 101

Once you have confirmed that the failed device is installed properly

• Establish a baseline, duplicatable, consistent failed indication

• Try most likely fixes one at a time and re-test to baseline

• Simplify system to eliminate possible causes

• Look at what parts of a device or system do work

• Confirm output from any functioning parts

Intermittent Problems

• Duplicating problem may be difficult

• Service history may hold the answer

• Divide and Conquer, what part does work

• Confirming solution may be difficult

• Failure may disappear unexpectedly

• Note operational parameters when failure shows up

• Patience, Perseverance and Professionalism

How hot is TOO hot?

Here is some interesting reading regarding the effect of thermal environments on electronic components…

The Case for Thermal Planning “Reliability Through Thermal Management”

“…from the quality assurance department's point of view, if we can lower the temperature by 10 degrees, we'll double the reliability.” – Steve Somers, Extron

“85ºF is the maximum recommended constant operating temperature for most equipment; it will help provide a long service life for the equipment inside an enclosure. Why 85ºF? Most studies have shown that for every 10ºF rise over 85ºF, digital equipment life is reduced by approximately 40%!” - Bob Schluter, Middle Atlantic Products

Waste Heat Calculation

Practical Application “Reliability Through Thermal Management”

Most equipment converts almost all of the power drawn into waste heat. In calculating BTU/Hr, output for most equipment is simple: the more current it draws, the more BTU/Hr. will be produced. One Watt of current equates to 3.413BTU/hr At 117 volts, each ampere of current drawn produces exactly 400 BTU/Hr. of heat output.

Waste Heat Calculation

Practical Application “Reliability Through Thermal Management”

Consider a common black box processor running a 25kW radar which consumes 249W: 3.413BTU/hr x 249W = 850 BTU/hr of waste heat. This amount of waste heat needs to be considered and addressed when planning the layout of your installation. Furthermore, you need to consider ALL generation of waste heat in the spaces where you will be placing electronics components.

Airflow Considerations

Practical Application “Reliability Through Thermal Management”

There are three airflows involved in a thermal system: How the heat is produced by the equipment How the air moves throughout the space How space heat is removed. The interactions between these airflows are important, and must be considered when taking a systems approach.

Design Considerations

Practical Application “Reliability Through Thermal Management”

How is the equipment designed to dissipate waste heat?

Radiation (from the device) Conduction (utilizes heat sinks) Convection (utilizes fans)

In general heat sinks are used to increase the heat dissipation from hot devices because the heat dissipation between the heat sink and the surrounding air is more efficient than between the device and the surrounding air. The thermal energy transfer efficiency of heat sinks is due to the small thermal resistance between the heat sink and the air

Design Considerations

Practical Application “Reliability Through Thermal Management”

How does air move throughout the space?

Design Considerations

Practical Application “Reliability Through Thermal Management”

How is waste heat removed?

ACTIVE (forced air)

PASSIVE (convected air)

Design Considerations

Practical Application “Reliability Through Thermal Management”

Whether you will be using a forced air or convection system to manage your waste heat for your installation, there is one important rule to keep in mind:

DO NOT ALLOW HOT SPOTS TO OCCUR!

Improper thermal planning can actually create heat build up that would not have existed if you had done nothing.