Cameron BARTON 289A - Section 3-Maintenance and Calibration; Tools

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Section 3 Model 289A Differential Pressure Indicating Switch
Section 3—Maintenance and Calibration
The following checks are recommended for preventive maintenance:
• Periodically inspect alarm switch mechanism to verify that all mounting
screws are seated properly.
• Inspect linkage for wear.
• Inspect integrity of electrical circuits. Tighten as necessary.
When repairs are necesssary, review this section for maintenance procedures
such as bezel/lens installation and removal, pointer installation and removal,
indicator calibration, switch calibration, and switch set point changes.
IMPORTANT: DPU maintenance is not addressed in this manual. See the Model 199
DPU user manual in Appendix A for related warning/caution notices and
instructions on DPU inspection, cleaning, service, repair, range change,
and BUA replacement. Neverperformmaintenance/repaironthein-
strumentorDPUwithoutrstreviewingallproceduresandwarning/
caution notices in the DPU manual.
Tools
The following tools are recommended for general maintenance of the Model
289A DP indicating switch.
Table 3.1—Tools
Equipment Purpose
Pointer Puller Pointer removal
Small Screwdriver Calibration adjustment
Medium Screwdriver Bezel removal and replacement
1/4" and 1/8" Open-end Wrenches Zero (1/4") and Range (1/8") adjustments
1/8 Hex Allen Wrench Switch set point adjustment
3/32" Hex Allen Wrench Drive Arm Tightness Test
Bezel/Lens(orCover)InstallationandRemoval
To remove the bezel and lens (or cover), perform the following steps, using
Figure 3.1 for reference.
1. Loosen the three screws on the front of bezel.
2. Tilt the bottom of the bezel and slide the bezel upward.
To reinstall the bezel and lens, assemble the components per Figure 3.1,
page 15. The two snubbers (Part No. 9A-C0266-0028C) on the scale plate
should not be compressed against the lens cover and the pointer should not
touch the lens.