There are a few typos in the Quail chart: “30 250V” “30 120/208V” should read 3ø 250V 3ø 120/208V, but are close to obsolete for lack of a grounding pin. OTOH, there is a completely different set of US/NEMA locking wiring devices, that are a bit more common in commercial/industrial applications. Also, I have seen in places like McDonald’s [cardboard] Hamburgers—rugged, often “washdown duty,” circuit-interrupting pin-and-sleeve devices, that fit the IEC309 series 2 dimensions.
