Why ? This is a big issue for me, because I want to add a mini-split for an addition. I'd put the compressor (outdoor unit) near the compressor for my existing heat-pump, which is on a 60-amp circuit (from an old inefficient HVAC) but has only 35-amp labeling and 16 amps running current. So the 12,000 btu/hr mini-split I'm looking at (20-amp breaker and 5.5 amp RLA) could EASILY live on the same circuit. I hate to run another circuit, because it's far from the breaker box and I'm short on spare slots. When the heat-pump dies (it's 15 years old and only 11 SEER) I'd add a second mini-split and that'd handle my whole house, hopefully. If it really MUST be on a separate circuit, I suppose I could run a sub-panel off the 60-amp circuit.
This is a tangent better addressed in the DIY section. Can you pick it up there?