I'm trying to resolve an issue I'm experiencing with some overhead power distribution lines, was wondering if anyone can help me out. Here is the scenario: three phase, 4 wire, wye connected 13.4kV power distribution system. 556.5kcmil bare ACRS wire is mounted on a crossarm 24" apart over a 200' span between poles. When a fault (short circuit) is experienced downstream of this location due to a separate unrelated event (equipment failure etc.), the wires at this location are coming together and creating a second fault (short circuit). I can see visual evidence of this happening in the form of burn marks and pitting on the wires, as well as I have eye witness accounts of this happening. What I suspect is happening is that the fault current from the original fault (~20,000 amps) is passing through this location and is creating enough magnetic force between the wires to draw them together and make contact, thereby creating a second fault. What I want to know is how do I create a formula that tells me how much current is required to make the wires touch, or conversely how far apart I have to separate the wires in order to have them not touch for a given fault current. I assume the variable inputs are: Wire spacing Wire tension Wire sag Span length wire diameter wire weight per ft Can somebody help me get pull together the formulas I need to figure this out. Attached is a diagram to help hopefully.