Hint: Cracked coupling!
I’m not sure what caused this EMT coupling to snap apart, but it resulted in damaged circuit wires and a compromised equipment ground path. This installation no longer complies with Sec. 300.10 with requires metal raceways, cable armor, and other metal enclosures for conductors to be metallically joined together into a continuous electrical conductor.
Metal raceways and cables must also be connected to all boxes, fittings, and cabinets to provide effective electrical continuity. That continuity is lost here. The effective ground-fault current path required by Sec. 250.4(A)(5) is most likely compromised by this broken coupling too. The circuit wires are damaged beyond repair and will need to be replaced or cut back, boxed, and then extended. Splicing the conductors inside the EMT raceway is prohibited by Sec. 300.13(A). If thermal expansion and contraction, or vibration caused this coupling to break, then perhaps a flexible wiring method could be used here to prevent future damage.
