These ground bar terminations were completed by an unlicensed, yet experienced, 'mechanic' Electrician. After capturing this photo, I cut the exposed copper, re-stripped the conductor, flipped the bus bar & torqued the lugs.
(Not my work, just an example I photographed of poor workmanship.)
The photo above helps us to understand how "workhardening" of individidual electrical conductors affects every first year Electrician or diy homeowner.
However, Newbies using
solid wire, with mechanical connections, will likely complete their solid terminations satisfactory, the very first time. Without need to add a low amperage, crimp on connectors (half assed) added to the tip. Instead, with solid copper, we just bend one hook & tighten a screw.
Use a square shaft flat head for torque. Makes it hard to mess up.
Stranded wire IS also solid, SouthWire brand stranded MC is comprised of 19 tiny SOLID wires. Every time we kink a single strand, the stray strand becomes bent & weakened. AkA Workhardened.
(My Stranded hooks, Twisted counterclockwise, while bending)
Every sparky, including myself and most others, have kinked and lost a strand (or two) while making terminations. Each strand of the #12, referenced above, carries about 5.05% of the total current carrying capacity. Break two strands, even one at each end, equates to a 10.1% increase in resistance, being added to the remaining 17 strands. Repeat at each device & joint...
Resistance Adds, defined.
It's easy for seasoned professionals to make mistakes with stranded terminations. Many have scored a strand (or two) of copper with wire-strippers , then snag one (or more) when we remove the insulation. Then we make dull, smashed, jagged cuts. No wonder we can't thread a terminal in the dark. Lol.
Meanwhile, AC devices (gfcis, recepticals, switches) bus bars, lugs, breakers.... they all have a screw type terminal. Wrapped, set screw, pushed through a lug hole... performing the work sucks w/ stranded.
(solid)
(solid)
(stranded pigtails on temp ltg)
DIY skoolie builders will likely perform their electrical terminations for their first time. The learning curve is steep with stranded.
Anyone who DOES use stranded for AC, please see
Post #65 of my tutorial, for detailed help terminating devices, using stranded.
My point is, no amount of skepticism & speculation about vibrations & flex, compares to the real and present dangers related to terminating AC devices with stranded verses solid. The statistics are high, with terminations & joints. No photos of solid Cu conductors, broken by vibrations.
We truely ought to end the flex theory on skoolies. I'll continue to preach about using more cable/pipe straps, cable-ties, wire staples, tie-wire, etc so that all systems move in unison, same frequency.
Linear Mode
