An example of a three-point controlled regulation valve is shown in the following figures.
The example uses a three-point controlled DANFOSS AMV 20, a drive with the 230 VAC supply voltage, power consumption 2 VA.
The actuator is controlled by a standard three-point control closing-idle-opening, which is used e.g. also for shutter drives and its electrical connection is identical. Two independent switching contacts can be used for electric control, or a specially connected output with two relays and mutually blocked switching of both outputs (see this article). You must always make sure that both outputs are not switched on simultaneously.
Fig. 1. Basic principles of (connecting) three-point drive control
Fig. 2. An example of connecting a three-point controlled AMV 20 drive