Summary of the Lectromec DelTest™
- Use in-situ or in lab as a non-destructive means of detecting wire insulation breaches in wiring harnesses
- Can be used with point-to-point testers to identify breaches (patented technology)
- Provides superior wire insulation breach detection than current technologies
Introduction to the Lectromec DelTest™
The Lectromec DelTest™ is a patented technology that has been used by commercial and military organizations to support their maintenance efforts and maximize the service life of their investments. The DelTest™ identifies breaches in wires that often go undiagnosed until an event happens. These events, common to active aircraft, can lead to spurious signals, noise, and electrical arcing. These failures may result in avionics and equipment malfunctions, damage to the aircraft or personnel, in-flight fires, or an incident or accident. The risk of these negative effects may be minimized or eliminated by detection and repair or rewire of the harness.
When the wire insulation is breached due to crack or physical trauma, the possibility exists for unintended electrical paths. However, in most cases an unintended path is not made because of the high resistance of the air that fills the breach and the high surface resistance of the insulation around the breach. Of course, if the metal structure were to touch the wire at the breach point or if water condensation occurred, a conducting path could be formed.
The DelTest™ process involves wrapping a water tight sleeve around a short section of the target harness and injecting water into the wrapped area (length of wrapped area dependent on harness accessibility). The water is cycled through the target area and a voltage is progressively applied to the wires/cables; breaches and leakage currents are recorded.
Lectromec participated in the recent Federal Aviation Administration (FAA) sponsored Intrusive Inspections of six newly retired commercial airplanes. Approximately, fourteen harnesses were tested on each airplane comprising all different wire types, functions, sizes, capacity, and locations. Lectromec used its DelTest™, in-situ, to detect any instance of broken insulation.
A visual inspection team inspected the same harnesses separately. Lectromec found approximately 60 instances of damaged wiring insulation on the six aircraft. The harnesses tested were removed from the aircraft and sent to a lab for verification. The 60 finds were all verified in a laboratory. Of the 60 finds, the trained visual inspection team only detected two.
The DelTest™ can be used to evaluate the conditions of newly delivered wire bundles or those from an in-service aircraft (this can be done to support the EWIS assessment required under the MECSIP process in MIL-STD-1798). For harnesses with additional sleeveing, or specialty harnesses designed for aircraft, missile systems, or any other systems, the DelTest can improve product reliability by flagging the ones with existing insulation failure. In the case of an in-service aircraft fleet, selected in-house DelTesting can be performed on selected wire bundles to determine those in the greatest need of replacement or repair. Lectromec’s experienced staff can help with the development of a targeted program that minimizes the cost and downtime of the fleet.