Voltage Drop on a branch circuit

[NCVideo]

I have an older property that was added on to in the 60's. In that out building there is a subpanel connected to the main at the house. The panel meters 224v, the individual breakers meter 122, the outlets meter 122. Testing the outlets shows all are wired properly, no hot ground or neutral. BUT, when I apply a load to a circuit, the voltage at the outlet drops to 72-80v. No other load is on the panel, all the other breakers are off. The same results occur over each of the 120v circuits. The feed from the main panel is 220, 3 wire RWB. Anyone got any ideas?

 

[tom baker]

Yes I have an idea this is a DIY post. Your profile states "video engineer". How are you related to the electrical industry? PM me if I have this wrong.