The actuators on Granzow's 100, 200 & 300 series motorized ball valves are power to open and power to close, and all have at least a 40% duty cycle. All actuators feature a unique "All in One" system which allows wiring for both standard on/off and variable flow service.
Standard on/off service (2-point or 3-point): Starting from the closed position, a continuous power signal drives the actuator 90° until the valve is fully open. Switching the current to a different terminal in the actuator, via an external customer supplied switch or relay, reverses the rotation of the actuator until the valve is again fully closed. The limit switches controlling the rotation of the actuator can also be used for feedback on valve position or to interconnect to other devices.
Variable Flow service (3-point): Starting from the closed position, a continuous power signal starts the opening phase of the valve. With the variable flow service the valve can be stopped in a partially opened position, and at any time it is possible to continue to open or close the valve from this position.
In case of power failure the valve will remain in its current position. Manual override is available as an option.