I'm trying to find the other half of this connector. If you can't read the plate,it says 323-N 3P 4@ 100A 600V.
However, it sure looks like it only accepts 3 conductors plus ground. I don't know what this is and my electrical supplier has been "looking into it" for me for two days but no luck yet.
Any info appreciated.
![[Linked Image]](https://www.electrical-contractor.net/PC/MysteryPlug1.jpg)
![[Linked Image]](https://www.electrical-contractor.net/PC/MysteryPlug2.jpg)