Usage of 125V 20A receptacle for 240V 1A circuit
Use a 12V/1A enclosed chassis mount (or DIN rail mount, for that matter) supply
Your problem here is that you are trying to apply a &quot;wall wart&quot; in an application (inside a control panel of some flavor) where you'd be provisioning a receptacle solely for the wall-wart's use.  This is a waste of a receptacle, and also poses NEMA 5/NEMA 6 confusion hazards, so why not use something more fit for the job instead, such as a DIN rail mounted supply like the one shown below? (It's a CUI PDRC-24-12, BTW, and is fully cULus listed to UL508 for field application in industrial control equipment.)

Of course, more traditional enclosed chassis mount supplies will work, although they don't usually carry a full UL listing the way the supply I linked does.