As far as this instance.. I'll agree with John as it being unfair to down the Wago connectors based on the BBQ'd neutral here... A 14 AWG wire with the amount of load that had been placed on it in this instance had to of gotten to some pretty lofty temperatures! [Linked Image] Not to mention ambient temperature where this was, was well into the 100's F on a daily basis due to the machinery run here.. This actually says something for it's endurance, since it lasted at least 3 years.. (When the other "electrician" added load to the box in question, whether the Wago's were there before that, of he installed them, I couldn't say)...
As I said earlier, I never did locate the overcurrent protection governing the wiring in the burnt neutral pic... I just snipped it at another box to make sure no load would be put on the burnt connection... For all I know so far, this could be on a 100A breaker! [Linked Image] & with the load it was carrying, finding it ending up at a 30 or 40 amp breaker wouldn't suprise me, or even finding 2 circuits/same phase bundled together someplace!
While troubleshooting I pretty much ruled out the "overlaid phasing" on the connection in question.. Disconnecting the 14/2 romex eliminated power to all the problem areas I spoke of earier...

-Randy

PS... Does this mean I think Wago's make a better connecton than a properly made up wirenut? Nope!, But Wago's seriously come in handy when I need to remake up a box that someone has left 2" of wire to work with in! Getting a wago on properly can be done... A wirenut? Hmmmmm.....