I've got a logic question here and don't really know how to approach this.
Got three water source heat pumps. Need to only allow two to operate at one time. To complicate things a bit more, I need the do a few odd things with valves to run a 2nd booster pump when unit 3 is operating with other units.
Got a water cut off valve for each heat pump. Call em (HP)1,2,and 3 with valves V1,V2 and V3.
Possible states of units and valve positions look like this:
Units on: Valve1 V2 V3 pump#2
1 on on off off
2 on on off off
3 off off on off
1+2 on on off off
1+3 on off on on
2+3 off on on on
The oddity here is that I need valves 1+2 open all the time unless unit 5 is on.
Were do I find a way to setup logic for this? Can you point me to a device that can be programmed to do logic like this?