On Friday, August 1, 2014 10:46:28 AM UTC-4, wrote:
On Fri, 1 Aug 2014 06:42:25 -0700 (PDT), wrote:



trader4 says: " It seems like they have established their own neutral,

unconneced to the service neutral, going to the other units. "



My assumption is that this is not a self-establised neutral, but the wiring control (from the indoor evaporator) that tells the outdoor condenser to switch from A/C to heat pump.



Side note: kind of strange to me that the indoor units are 220VAC. Call me paranoid, but



The mini splits are usually "inverter" designs so they do generate

their own voltages in the unit. I bet the voltages going to each

inside unit are not line voltage at all. The ones I have use a low

voltage (24 or so)

Interesting. I just assumed line voltage in, line voltage out,
which I guess it isn't. As you point out, all they really need is
power for the fan and a communications link of some kind, so how
they do it is up to them.