These weren't sold for home use!  These were for lunch counters etc... Just because they've surfaced on Ebay doesn't mean anything about their intended use!  i have the Hotpoint catalog for these items.  All were 220 V.  

We have an ad that surfaces here, I think it's here, that shows a Hotpoint kitchen and there is one of these in a below counter cabinet that can rise to be used, much like those under counter cabinet lifts for mixers. I did not dream it and wondered when I first saw it what kind of  entertaining would require one of these and what kind of ventilation one of these would require in a domestic kitchen. That's why I wrote that the modular two unit cooktop with the deepwell and the plug behind it for the Golden Calrod Deep Fryer seemed a better fit for most kitchens and most families.