Masoneilan SVI II AP Installation and Maintenance ... - GE Energy

Rotary - 90°
Installation and Set Up
Figure 10
Model 33 Actuator
Rotary - 90°
For actuators with 60 to 120° rotation, follow the instructions in “Mounting the SVI II AP
on Rotary Valves” on page 31 except mount the magnet at plus or minus 45° while the
actuator de-energized as shown in Figure 10 on page 35.
Magnet Orientation on Rotary Valve Shafts
The same mounting hardware is used for Models 35, 30 actuators. For each actuator
type the magnetic coupling must be properly oriented to the active sensing angle of the
positioners Hall Effect sensor. The active range of the Hall-Effect sensor is plus⁄minus
70° from the null magnet axis. If the total valve travel is less than 60°, allowing a margin
for tolerances, the best accuracy is achieved by mounting the magnet with the axis
vertical in the valve-closed position. The location of the magnets in the ring of the
magnet holder. The axis of the magnets is the line through the centers of both magnets.
Mount the magnet holder with the magnet axis vertical on the 35, 30 when the valve is
closed. If travel of the valve exceeds 60°, the magnet must be assembled to the rotary
valve shaft so that the magnet axis is vertical when the valve is at mid-scale.
Dismantling the SVI II AP from Rotary Valves
WARNING
Before carrying out any work on the device, power off the
instrument or make sure that the device’s location
conditions for potentially explosive atmosphere permit the
safe opening of the cover.
To remove the SVI II AP digital valve positioner from a rotary valve perform Steps 1 - 8
on page 28 in reverse.
35