I have a project with a meat preparation cooler. A machine needs a three phase receptacle drop at 5' AFF from ceiling. The receptacle is a twist-lock type. I understand we need another flexible cord with twist-lock type attachment plug to plug in the receptacle. My question is if the flexible cord dropped from ceiling needs an attachment plug to meet article 400.7(B) or they can be hard-wired into a junction box at ceiling. I am not quite sure about this. Thanks.