A Maintenance Supervisor explains why he believes removal of accumulated dust found on and around avionics electrical racks during a B-check is not required because a scheduled Electrical Wiring Interconnect System (EWIS) inspection had not been assigned to that B-check Maintenance visit.

Narrative

I was informed by our Quality Assurance Manager about an investigation involving me. To the best of my recollection; the events are as follows. Aircraft was in for a B-check and during a scheduled change of a Line Replaceable Unit (LRU) in the E-7 rack (I believe it was the APU battery); dust was discovered on some wire bundles behind the racks. I viewed the area and found this to be true. I also have had just completed Computer Based Training (CBT) regarding Electrical Wiring Interconnect System (EWIS) issues. In the [CBT] module four; I believe slide thirteen or fourteen; it explained the intent of the EWIS program.This statement was to the effect that cleaning of wire bundles are to be accomplished during a scheduled EWIS inspection when a specific card is issued against the aircraft to accomplish the inspection. In this event a specific EWIS inspection had not been assigned to the aircraft. The training given to us also places emphasis on not disturbing wires unnecessarily.It is my belief maintenance would have done more damage than good at this time; dragging a vacuum [cleaner] through tight spaces to clean up the dust. After this event; I pulled together the required departments necessary to write an Engineering repair order for the fleets to address this issue. An Engineering Order (E/O) was shortly issued and is consistent with what I had done. The findings of the dust in this event were not part of an EWIS inspection or repair to any EWIS wires. In this event; cleaning of the wire bundles may have caused more damage then good and it would have never stopped. As wires were cleaned; more dust accumulation would be found down the entire length of the aircraft. This I believe is not what the EWIS program is supposed to do.