2 stage heat pump with hot water coil

[Herb - hunterdon a/c]

we have a 2 stage heat pump with hot water back up.
with two or three zones.
If set 50% rule how does the second and third stage cut in if only one zone is calling.
as in y1 - y2 - w

Herb

[Paul Z.]

50% rules hold off staging until two (2) or more zone are calling together.