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

Check Out and Power Up
4
Overview
This section provides the checkout procedures required to determine if the SVI II AP is in
working order and to power up the unit.
NOTE
Perform all procedures in this section before putting the SVI II AP into
operation.
Position Sensor Principles
The motion of the control valve (position) is precisely transmitted to the SVI II AP by a pair
of rotating magnets located outside the instrument housing. Rotation of the magnets is
sensed internally by a Hall Effect sensor. Because the only connection through the case is a
magnetic field there are no seals or bearings to wear or corrode.
The rotation of the magnet is linked to the valve position by the mounting hardware
provided. For a rotary control valve the magnet assembly is normally attached directly to the
actuator shaft. For a reciprocating control valve the mounting kit includes the magnet
assembly mounted in a sealed bearing with a lever that must be linked to the valve stem.
The positioner must be installed with the gauges to the left and the housing display and
cover to the right. The ½ NPT conduit entries must be facing down to drain condensate
away from the housing. The positioner can be moved on the valve for best drainage
depending on the position of the valve in the pipeline.
61