If you try to apply
power from the Trex unit when the device is externally-powered, the Loop
Diagnostics application prevents the Trex unit from supplying power. This
protects the Trex unit from damage.
Warning: Connecting power to the
positioner may cause changes to the tuning set that cause the valve/actuator
assembly to stroke. To avoid personal injury and property damage caused by
moving parts, keep hands, tools, and other objects away from the valve/actuator
assembly.
Warning: When power is provided to a
positioner that is in service, the valve may move causing process fluid or
pressure to be released. To avoid personal injury and property damage caused by
the release of process fluid or pressure, isolate the valve from the process
and equalize pressure on both sides of the valve or bleed off the process
fluid.