Cameron BARTON 289A - Page 27

27
Model 289A Differential Pressure Indicating Switch Section 3
Table3.2—Troubleshooting
Problem Possible
Source
Probable Cause Corrective
Action
High
Indication
Primary
Source
Orice partially restricted or too small Clean out or
replace
Primary
Element to
DPU piping
Piping leaks on LP side Repair leaks
Bellows
Unit (Refer
to DPU
Manual)
Gas (liquid service) or liquid (gas ser-
vice) trapped in housing
Vent housing
LP housing gasket leak Replace gasket
Range spring broken or DPU tampered
with
Return BUA for
repair
Indicator,
Alarm-
Switch
Mechanism
Loose linkage or movement
Tighten or replace
Out of calibration Calibrate
Erratic
Indication
Primary
Element
Flow pulsating Install dampening
device upstream
of DPU run
Primary
Element to
DPU piping
Liquid (gas service) or gas bubble
(liquid service) trapped in piping
Remove
Vapor generator incorrectly installed Re-pipe
Reference leg gassy or liquid vapor
-
izing
See piping
instructions in
DPU Manual
Bellows
Unit
(Refer
to DPU
Manual)
Obstructed bellows travel Clean bellows
Gas trapped in DPU HP or LP housing Remove (see
startup proce-
dure)
Linkage dragging or dirty Adjust or clean
Pointer dragging on scale plate Adjust pointer
position
Inaccu-
rate or No
Electrical
Alarm
Power
Supply
Blown fuse Replace fuse
Broken or loose wire Repair
Alarm
Switch
Switch not properly adjusted Adjust switch
Dirty or burned Replace switch
contacts