I have a 150 amp 120/240 and a three phase panel that are connected by 4 wires. two of the 120/240 is shared between two separate meters/panels. The 3 phase panel is also connected to an extra wire that I believe is High leg delta.
A neutral/ground bare wire enters the 120/240 meter/panel. In resume total of 4 wires come from the pole, two insulated black and one bare goes to 150 amp single phase. The same two black are also shared with the 3 phase plus another wire that I believe is a high leg delta. I want to wire a 60 amp subpanel in an attached guest house of 500 square feet, about 70 feet from these panels by feeding a 60, 70 or 80 amp breaker.
Does it make a difference in which panel I should install the feeder breaker? The guest house is wired for 24" electric stove. An electric Ac already is connected to the main 150 amp panel. The main house has a 24" electric stove and electric dryer. The wire that brings service to the guest house is #4 ALU SER service entrance.