Blog

New Means to Assess Corrosion Susceptibility

November 2, 2020 Michael Traskos

Low outgassing materials are critical for space applications. As one might imagine, a small, enclosed space with outgassing materials is not an ideal environment. To that end, space system developers have always sought insulation constructions with low outgassing properties. In past articles, Lectromec has covered the developments of the methods and materials used to reduce outgassing. Here, we examine the latest testing techniques for these materials. Read more

WPAFB Wire Study

October 14, 2020 Michael Traskos

Key Takeaways Publicly available recorded data compares many of the commonly used aerospace wire types. Corona extinction and inception voltages of cables decrease drastically with an increase of elevation. Many insulation types display a significant decrease in mechanical durability at increased temperatures. Modern wires of the AS22759 family are incapable of stopping 270 voltage DC […] Read more

IEEE 1584-Arc Standard

September 16, 2020 Michael Traskos

Key Takeaways IEEE 1584 provides a basis and a model for arc flash protection and necessary safe separation distance. The standard targeted the necessary calculations for power distribution. While there is some overlap with the aerospace industry wiring system requirements, the model’s range inhibits its use for aircraft. Research down an unfamiliar path often includes […] Read more

Conductor Resistance ASTM B193

August 13, 2020 Michael Traskos

The measurement of resistance seems to be a trivial task. Hook up a standard handheld multimeter with two probes and attach the probes to either side of the device or component that you want to measure. For the most part, this process works well. More correctly, for devices with resistances between 2 Ohms and 1M Ohm, this is a good technique, however, once the resistance values get really high or really low, the process becomes a little more complicated. While the basic physics remains the same (Voltage = Current * Resistance), getting the setup to correctly measure the component requires attention to detail. Read more

AS4372 – Building a Wire/Cable Specification

July 27, 2020 Michael Traskos

While it is possible to start from scratch and develop an independent set of tests and performance requirements, there are existing standards that can be used to expedite the process. Read more

Selection of Zones for Degradation Testing

June 26, 2020 Michael Traskos

Maintenance zones within an aircraft are not homogeneous. They vary from the extreme Aircraft areas within the aircraft (engines) to more benign areas (inside pressure and temperature-controlled areas). And because of this, the components within each of these zones will age at different rates. Naturally, different components are selected for each of these zones; those components better able to handle the severe environments are installed in those environments, and lower requirements are placed on those parts installed in benign environments. Read more

Solder Sleeves and Splicing in Shields

May 15, 2020 Michael Traskos

Shielded cables are necessary. They provide necessary EMI protection to ensure signal fidelity, and in some cables, such as coaxial cables, the shield is integral for signal transmission. Trying to use only non-shielded cables in any modern design would encounter such a significant impact on performance, it may not be possible except for a limited number of applications.

Because of this need for shielded cables, there is a wide range of components and supporting technologies to ensure proper use and reliable transmission of data. One of these technologies is a device to help with shield termination.

Dielectric Constant

April 22, 2020 Chris Wollbrink

There are some properties that are taken for granted with wires and cables until they are needed for precision applications. A conductor’s conductivity is assumed until the impact of a voltage drop or heating must be determined. In the same way, a cable’s dielectric constant is uninteresting until the integrity of high-frequency signals becomes critical.

This last property (dielectric constant), is important not only for cable insulations but also for a wide range of applications.

Light Weight and Normal Weight Wire Constructions

April 10, 2020 Michael Traskos

Saving weight is a large part of any aircraft design. Naturally, the electrical system is not exempt from the goal of shaving off a couple of pounds. This often comes in the form of looking for lighter connectors, lighter clamps, and also lighter wire constructions. Those that have done this have undoubtedly come across two classifications of wire construction: “Normal weight” and “light weight”. Of course, if the EWIS has to go on a diet, then the “light weight” construction looks like a good substitute for the “normal weight”… after all, why would the wire be called “light weight” if not for satisfying weight requirements. Read more

The Impact of a Short Circuit on Conductor Performance

March 17, 2020 Laura Wishart

Over-current and shorting are an ever-present risk to power wires and cables. The hope is that circuit protection can quickly respond to over-current conditions fast enough to prevent any damage to the circuit components. Wire conductors have a temperature rating, limited by the plating, because that is the established temperature for long-term reliability. But what happens when a single wire is exposed to repeat over-current conditions? Does the latest generation of circuit protection sufficiently protect the wiring? Read more