This is a new one on me. Anyone seen this before? What’s your opinion? 1st photo is the feed from the main panel to the sub.
It would have been just as easy to make it into a 240V panel. My guess is that someone just didn’t understand the “concept.”
Did the circuit have a neutral and a grounding conductor?
A little odd…but when people are left to there own devices…240V would have been the way to go!
What was the amp rating of the aluminum feed cable, does the breaker match the wire rating and what were the loads on the subpanel?
In the end, IMO, it is not a professional wiring job (from what I’m used to seeing in my area). I’d call it.
It appears that they ran SEU (3 conductor) type SE cable instead of SER (4 conductor). That made them one conductor short. Maybe they initially planned on not separating the neutrals and EGC’s as required. It is a poor design but probably code compliant if the calcuated load is less than or equal to the ampacity of the OCPD and the feeder conductors. I see a 70 amp CB, what size is that aluminum conductor?
I think it’s a safe bet that no “calculations” took place prior to this installation. 
If in doubt, recommend a state licensed electrical contractor evaluate panel and ensure safe to use as is!
I would think to make it safer they should have made it a single pole would you not think . ( thinking it may have drag if tripped)
I would refer this panel for sure.
There’s nothing “technically” wrong with wiring it as a 120V panel. It is, however, indicative of “unprofessional” workmanship, but I see no reason to defer it to anyone.
Based on what I can see, I would simply report is as a 120V panel in my report and move on.
4 awg
I agree, assuming no other issues present. At least they labeled it 120V.
Similar to a subpanel fed with 3 wires instead of 4, all they have to do in most cases is label it “240V only” and ignore the missing neutral. This of course assumes that the loads are all 240V and no 120V loads present.
Under the 2008 NEC, if this is SE cable, then the CB is too large. Even under early code cycles the breaker may be too large unless there was a load calculation done to prove that the connected load is 65 amps or less.