I'm sorry I can't answer your question, but I did want to point out that when people are starting to draw over 15 amps from their outlet you do need to ensure the following:
- The breaker is rated for 20 amps (that way you will also know the existing wiring from the outlet to the breaker is 12 gauge.
- The outlet is rated for 20 amps (as you are looking for). Usually these outlets have a horizontal slot on the 'left' receptacle's input as shown below.
- The plug itself is rated for 20 amps (as shown below).
- The wire from the appliance to the plug is at least 12 gauge in size.
I've had various items (at work) draw over 15 amps without the above items in place, and that plug does get very hot!
If you don't have an answer to your question here, call Automated Outlet or Worthingtons.