This is a slightly sad topic.
In North America, the codes for HVAC units are not adapted to mini-split units. All the electrical codes you will find for HVAC were written decades ago for "normal" HVAC units, which are much bigger, usually only 1 or 2 units per house, and draw a lot more power, are in more standard locations, and are more permanent. This means the electrical codes are overkill for mini-split units, which are by their nature cheap, quick, and low-power, stuck in "creative" locations, and are often present in much greater numbers. However, none of the codes have been modified to take mini-splits into account, so if you want to do things by the book, you have no choice but to follow standard HVAC codes, and that's the way it is unless you are willing to do it all yourself and just ignore the codes. This has the effect of making mini-split installs more expensive than they should be.
- Every outdoor unit must have a convenience receptacle nearby within 25 feet. This means you often have to install one, unless you get lucky and already have an outdoor receptacle close enough. Remember the outdoor receptacle must be wet-rated, and GFCI like any other outdoor receptacle.
- Every HVAC unit must be on its own dedicated circuit. Nothing is allowed to share the circuit with the HVAC...not even the convenience receptacle. This means you are often installing TWO new circuits for every mini-split you want to install...one for the unit and one for the convenience receptacle unless you can add it to another existing circuit.
- Every HVAC unit has to have its own disconnect (not a big deal in the scheme of things)
So if you install two mini-splits, you will need 2 new circuits. If you install one of the units that has a single outdoor unit and two indoor units, you will only need 1 new circuit. You may need new circuits for the convenience receptacles as well. In a new modern house that uses 4 separate 240V heat-pumps, it means up to 8 breaker panel slots will be taken up just for the HVAC.
