On Fri, 1 Aug 2014 04:54:14 -0700 (PDT), wrote:

Ok here is the logic
The manufacturer probably specified a 50 amp breaker to reduce trips during the startup inrush. You all know an a/c has a large inrush current.
Now if you are using a 50 amp breaker you MUST use #6ga or larger wire to be safe and meet code.
The breaker and wire size must match to be safe.
But it does seem the directions were confusing re the number of conductors needed.
6-2 is three total conductors, 2 that carry current and one safety ground.

Mark
Unless flexible cord is used - it said 3 conductor - which COULD be
read either way. And many air conditioner installations do spec
flexible cable between the house (disconnect) and the unit.
And remember - if the unit draws a constant 26 amps, it is over-spec
for a 30 amp circuit (maximum 80% rated current for continuous use)