Baffled at this rack wiring

[jasonallenh]

Due to the closures related to Covid, I'm using the downtime to replace a rack that is orders of magnitude too big. The rack has a conduit box mounted inside, so I'll have to cut power from the panel to pull the AC out of the box. The conduit box was run through the rack with flex conduit, so this is all very straightforward...

However, when I started the work, I discovered this cable with a male Edison plug dropping out from underneath the conduit box, which has been plugged into the racks power conditioners... As if the power conditioners were powering a quad box made from a conduit box... Except the box is also receiving power from the panel

The power conditioners' own mains connectors were connected to the normal outlets, so I have no idea what purpose this serves. I'm a simple man, have done plenty of diy projects and can certainly replace a light switch, but this goes over my head. Anyone know what this is for?

 

[JohnRoberts]

Be careful I've seen scary DIY mains wiring using  hot edison plug to transfer power to another box/branch.

One old neighbor (RIP) used such a dangerous hot male plug to power up his back yard shed when the underground cable failed. He plugged the energized male plug into an outlet to energize all the others in the shed.

JR

 

[jasonallenh]

Be careful I've seen scary DIY mains wiring using  hot edison plug to transfer power to another box/branch.

One old neighbor (RIP) used such a dangerous hot male plug to power up his back yard shed when the underground cable failed. He plugged the energized male plug into an outlet to energize all the others in the shed.

JR

After looking a little closer, this male plug seems to have its own dedicated line (L, or black) running from (?) while its N (neutral/white) is wired in parallel with the conduit box's Neutral. The Line from this male plug just runs back into the conduit and off to wherever. My A1 neglected to tell me that he broke our DMM, so I'm off to the store to get a new one.