NEMA L6 30 PLUG WIRING

How to Wire a NEMA L6-30R | eHow
The NEMA L6-30R is one of the receptacles approved by the National Electrical Manufacturers Association in the U.S. This type of female plug is a two-pole, three-wire, 250-volt, 30-amp locking receptacle. It has two hot wires and one ground wire; it is designed to lock onto a NEMA L6-30P male plug
Wiring NEMA L6-30 & L6-20 Receptacles - TheElectricBrewery
You're missing one of the two HOT lines and have X, Y, G connectors on the L6-30 (3 spade instead of 4) power input receptacle. It doesn't matter if you chose X or Y to be your HOT on the L6-30 plug. Just be consistent and make sure it lines up with how you wired your power cord all