Power conditioner wire gauge? Serious issue

Why don’t you mention what brand line conditioner you have and. The powercord plugged into it. Forsure get a dedicated line minimum 20 amp awg12

and 4 wire ,with common ground ,and a dedicated isolated ground with separate copper buzz bar ,  and your wall outlets should be very good quality 

$100 Pangea best very heavy duty high purity copper then gold plated  which like mine can clamp down on awg10 wire.

Most people use awg 12 from the breaker panel .

my Audiophile friend is also a master electrician ,I use awg 10 copper wire ,less resistance ,I also use 4 wire ,a common ground and a dedicated isolated ground in its own housing ,and separate buzz Barr, and heavy silverplated copper breaker which was expensive from Siemens Germany . just for the audio. Any top quality line conditioner usually use awg 12  copper wire