Domnick Hunter MINI DM002 Manual página 10

8. FAULT DIAGNOSIS TABLE
Problem Indication
Poor Dewpoint
HighD p Pressure Gauges
In/Out
Failure to Poor Dewpoint
changeover
Failure to purge No depressurisation Purge orifice closed
Loss of Dewpoin
9. KNOWN MISUSE
Filters
Lack of filtration.
Installation of inlet filters remote from the dryer inlet head, allowing possible condensation to occur
between filters and dryer.
Blow down the vale upstream of filters causing back flow / possible collapse of filter element.
Installing filters in wrong flow direction.
Opening inlet valve too quickly, causing initial high differential pressure across filter element.
Differential pressure gauge / indicator fitted wrong way around giving false differential pressure read-
ing.
Combining drain pipes from filters to a single drain valve.
Inlet / outlet head
Pipe diameter too small.
Pipework unsupported.
Inlet pipework taken from low point of manifold range, allowing bulk water intrusion into the dryer.
Additional Items
Use of non recommended componentry.
Untrained. unauthorised maintenance or installation personnel used.
Subsequent increase in air consumption without relation to dryer flow capacity.
Purging of pneumatic system and dryer with cleaning agents that have the potential to damage des-
iccant material.
Covers removed or loose during operation.
Probable Cause
Entrained water
Insufficient purge
Inlet pressure to low
Air flow demand too high
Inlet temperature
too high
Contaminated desiccant
Excessive outlet flow
Saturated inlet elements
or blocked outlet
elements
Cam timer not rotating
t
7
Remedy
Check prefilter/drain
Check & reset rate
Check inlet pressure
Check for recent additions
to compressed air system
Check and rectify inlet temperature
Check and replace desiccant and
trace source of contamination
Check and regulate outlet flow
Replace filter elements
Adjust screw on motor or replace
electric motor.
Reset purge on orifice