AVIONICS
components. Some devices may be damaged by discharges as small as 30 volts! These invisible forms of ESD can cause outright device failures, or less obvious forms of degradation that might aff ect the long-term reliability and performance of electronic devices. The degradation in some devices might not become evident until well into their service lives.
How to Identify ESDS Parts In order to protect ESDS parts from static discharge, we have to identify those parts that are susceptible to ESD and take appropriate precautions. Personnel who handle and work with these avionic components need to be familiar with the labeling that identifi es them as being ESDS parts. Some of the more common labels are shown below. These labels will not only be found on the parts themselves,
but on their shipping containers, storage units and where they are actually installed in the aircraft as well. Since ESDS
build up on ESDS electronics is prevented. International standards are used to defi ne typical EPA and can be found for example from the International Electrotechnical Commission (IEC) or American National Standards Institute (ANSI). The name of the game in protecting ESDS parts is to
prevent an electrostatic charge from entering the part. This is accomplished in two ways: 1. Electrically neutralizing anything or anyone that will come near or in actual contact with the part.
2. Electrically insulating the part from ESD. Remember that a charged body does not need to come into actual physical contact with the ESDS part to cause damage. The ESDS part should be kept a minimum of at least one inch from any other part that might have a static charge. Static-generating sources should be kept a minimum of 12 inches from the ESDS part. ESDS containers are the best way to store and move ESDS
parts from one location to another, including out to the aircraft for installation. Antistatic bags are currently available in two colors, pink and dark gray. The pink antistatic bag is used to protect parts from generating a static charge while moving around inside the bag. The gray bag protects parts from electrostatic fi elds outside of the bag and from static buildup inside the bag from the part moving around. Once the part is safely in the approved antistatic bag/container, it can be handled by personnel who are not grounded. Personnel who will be handling or installing the ESDS part need to be electrically neutralized also. This is typically
Common ESDS Labels
parts come in many diff erent shapes and sizes, they should not be handled without taking the appropriate precautions to minimize the risk of exposing the part to ESD. From receiving the part to installing it in the aircraft, the ESDS part should be handled with care at all times. ESDS protocol should be used.
Protecting ESDS Parts Prevention of ESD centers around creating an electrostatic protective area (EPA). An EPA can be a container, a small
Antistatic Bag
working station or a large manufacturing area. The main principle of an EPA is that there are no highly charging materials in the vicinity of ESDS electronics, all conductive materials are grounded, workers are grounded, and charge
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HelicopterMaintenanceMagazine.com April | May 2014
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