At my place of work, which is in the US, I had an electrician install a 3-phase outlet. He used a NEMA L14-20 receptacle and left us a NEMA L14-20 plug to connect to the device which uses the power. This is a 208 V installation (measures at 212V phase-to-phase, and all three phases present, plus GND). We plan to use it to power a servo-motor drive. The drive model is SVA-2300 from automation direct.
This doesn't seem right. Seems like he should have used a NEMA L15-20 receptacle and plug. Is it common or correct to use NEMA L14-20 receptacles for 3-phase power? Should I ask him to redo it or just use the plug he left for us? Obviously it will work and be safe for us, but it seems like if someone came along and plugged in something else to that outlet, it could be a problem for them.
He is a professional electrician and the work is well done and neat otherwise.
Edit History: added 'L' prefix. This is a locking connector. It is a 208 V outlet (measures at 212 phase-to-phase). Noted that all three phases are present. Added information about load.