TESTO 549, Instruction Manual

Page: 12 / 28

5 First steps
12
Representation Explanation
T
fac
Temperature compensation factor, icon is
shown on the display if the function is
disabled.
−
Settings will be applied following the final selection.
Operating valve positioner
The digital manifold acts like a conventional two-way manifold with
regard to the refrigerant path: The passages are opened by
opening the valves. The adjacent pressure is measured with valves
closed as well as with them open.
>
Open valve: Turn valve positioner anticlockwise.
> Close valve: Turn valve positioner clockwise.
WARNING
Valve positioner tightened too tightly.
• Damage to the PTFE seal (1).
• Mechanical deformation of the valve piston (2) leading to the
PTFE seal (1) falling out.
• Damage to the thread of the threaded spindle (3) and the valve
screw (4).
• Broken valve knob (5).
Tighten the valve positioner only hand-tight. Do not use any tools
to tighten the valve positioner.