Need advice for wiring a solar inverter powered well pump

[srukke]

Hope this makes sense. I have a 110v ac well pump. I have a 2000/4000 watt inverter that should run the pump no problem. I have the solar panels and charge controller wired to 3 deep cycle batteries then to the inverter. The inverter is not automatic so it runs fans and all when switched on. The pump is wired to a pressure switch that starts at 20 psig and shuts off at 40 psig. I do not want the inverter to constantly run so I would like to hook up the inverter either to the pressure switch or to some type of load sensor. The pressure switch has no unused relays so I am unsure how to wire the 12v inverter power switch through it if even possible. I could install another matching pressure switch for the 12v circuit only but may have trouble adjusting them both to match on/off cycles. Is there an easier way to do this. I can easily break the on/off switch circuit to the inverter and wire it through some type of switch. But what type? I know they make automatic inverters but unfortunately I already had this one. Is there a load sensing switch I can install on it?

 

[crutschow]

Perhaps it would work to disconnect the motor from the pressure switch and wire it to control the inverter. Then just connect the inverter output directly to the pump motor. That way when the inverter goes on and off, so will the pump motor.

 

[mbarazeen]

you can multiply the contact from your sensor using another relay that is having more than two contacts, also possible to operate relays for different voltage levels.