Honeywell FlexLine SmartServo 954, Service Manual

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MAINTENANCE
Part No.: 4417340 Revision 1 Service Manual 263
954 SmartServo FlexLine
Repeatability test (refer to section 8.1)
If repeatability deteriorates (more than 1 mm) the drum bearings should
be replaced (refer to section
0 ).
9.2 Instrument covers
Opening the instrument
The joints between each cover and the housing are waterproof IP65.
For this purpose, the covers of the servo, drum compartment and
terminal compartment are fitted with O-rings (refer to
Figure 9-7 ). Use a
metal rod (like a Tommy bar) for opening the covers.
Check the O-rings to assure water and dust protection. Refer to
Appendix A for the dimensions of O-rings.
Closing the compartment covers: In order to ensure that the covers
open easily, their screw threads have been greased.
Keep screw threads free from dirt. Grease them lightly with an acid-free grease before
closing the instrument. When closing, turn the covers counter-clockwise until the
thread clicks into place, then turn clockwise.
9.3 Drum compartment
Detailed description, in Figure 9-7 left-side, shows the cross-section of
the drum compartment of the medium pressure version and identifies
the components. Figure 9-7, right-side, shows the chemical and high-
pressure version. The drum shaft, mounted in the drum with a tolerance
ring, is inserted into the magnet cap. Two carbon PTFE bearings in the
drum shaft bushing support the drum shaft. These bearings should be
replaced when repeatability deteriorates.
The drum shaft bushing is kept in position by a circlip. The drum shaft
bushing is provided with an internal thread which facilitates removal
from the magnet cap.