All,
I am pretty certain this is no problem but wanted to pressure test this before I do it so Im sure I have not missed anything.

I have an existing 30A Circuit (consisting of two bridged 30A breakers), serving one Large Tandem 230/208V 30A receptacle for an old PTAC Unit.

I am replacing the old PTAC with one that only requires a Small Perpendicular 230/208V 20A receptacle.

My question would be... what are my options?

1) Do I replace the bridged 30A breakers with bridged 20A breakers and replace the Large Tandem 30A receptacle with a Small Perpendicular 20A? If so, will I have any problems keeping the same gauge wire in place?

Or

2) Can I simply change the receptacle to the 20A as the unit I am installing won't / shouldn't surpass the 20A capacity of the receptacle... while leaving the bridged 30A breakers and wiring in place?

Thanks everyone for your time, your responses are hugely appreciated.

You only have option #1 to chose from. The breaker and the outlet must be changed. Leaving the heavier wire is no problem at all.

You only have option #1 to chose from. The breaker and the outlet must be changed. Leaving the heavier wire is no problem at all.

Perfect, that answers that, thanks so much for the quick reply!