Then if it's that strange carry out two seoerate tests , the wiring and the power consuming equipment \, to try and eliminate one from the other, no good just testing it all in one procedure, any good detective will tell you to eliminate one area at a time just saying, others may call me an idiot, but been called worse. and have a thick skin.
Yes obviously 2 separate procedures ?
I wouldn't combine them
Test the cable at a high voltage and equipment separately , I didn't imply differently