You could replace the existing 240V line with the new one on that 30A breaker, but you cannot attach both to the breaker at the same time, no. (Called double-tapping; generally not allowed unless the model of breaker is listed for it. 30A and up are [AFAIS] never listed for it).Can I add a 220 line to an existing 30 amp dbl pole breaker with an existing 220 line. panel is 100 amp with 4 20 amp breakers and 1 30 amp dbl pole and 1 40 amp dble pole.
What is the load of the A/C unit? (In Watts or Amps).well only using line for ac window unit 220 plug , what do you recommend
What is on those 2 circuits?1 30 amp dbl pole and 1 40 amp dble pole
OK Mike. Let's try this from the top.well only using line for ac window unit 220 plug , what do you recommend