18
Table 3-1. Troubleshooting (cont'd)
Problem
Possible Source
Probable Cause
Corrective Action
High
indication
(cont'd)
Indicator,
alarm switch
mechanism
Loose linkage or movement
Tighten or replace.
Out of Calibration
Calibrate.
Erratic
indication
Primary element
Flow pulsating
M199 DPU – adjust
dampening;
All o hers – 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 vaporizing
See piping instruc ions
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
procedure).
Linkage dragging or dirty
Adjust or clean.
Pointer dragging on
scaleplate
Adjust pointer posi ion.
Inaccurate 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.
