Van Air Systems HLS-50-HLS-150 - Manual (Page 9)

PRINTED IN THE U.S.A. PAGE 9
MAINTENANCE & TROUBLESHOOTING SECTION 9
9.5 TROUBLESHOOTING
The following check list should be used as a guideline for troubleshoot-
ing problems. ARE THE TOWERS DEPRESSURIZING?
Check the purge valve for proper operation. Check the purge
muffler. It might be clogged. If clogged or damaged, replace it.
Use manual overide to check. (This should cause
depressurization.)
IS THE DEW POINT ACCEPTABLE?
• ARE THE INLET CONDITIONS WITHIN THE SPECIFICATIONS?
Reference Section 3.1 for the inlet conditions of the dryer.
Correct the inlet conditions if necessary. Excessive inlet flow will
greatly reduce the performance of the dryer.
• WAS THE DESICCANT INSTALLED?
Make sure that the desiccant was installed. Reference Section 9.3
for desiccant installation procedures.
• IS THE DESICCANT CONTAMINATED WITH LUBRICANTS?
Check the condition of the desiccant bed. If the bed is
contaminated with lubricants, replace the desiccant following the
procedures in Section 9.3.
• IS THE DESICCANT CONTAMINATED WITH MOISTURE?
If the dryer was operated under excessive inlet conditions, the
desiccant bed may be saturated with liquid moisture. Check
upstream equipment such as aftercoolers. Check the actual inlet
conditions, correct them and condition the bed following the
procedures in Section 5.3.
• ARE THE BYPASS VALVES OPEN OR LEAKING?
Check the valves (if installed). Repair or replace if faulty.
IS THE POWER ON AND RUN SWITCH PRESSED?
Check the main power source and check that the Power LED is
lit. Make sure that the dryer Run switch has been pressed and
that the Run LED is lit
IS THE SYSTEM PRESSURIZED?
The dryer is designed to operate at 60 to 150 psig. Check the
upstream equipment and any isolation or bypass valves.
IS THE DRYER CYCLING?
• IS THE CONTROL SYSTEM WORKING?
Is there incoming power to the control box.
• IS THERE CONTROL AIR PRESSURE, 60 PSIG MINIMUM.
Make sure that the dryer inlet pressure is above 60 PSIG. Check
the control air filter element and replace it with a new element.
Reference Section 9.4 for element replacement instructions.
• IS THE INLET VALVE FAULTY?
Rebuild or replace the inlet valve as necessary. Use manual
override to check.
• IS THE PURGE EXHAUST VALVE FAULTY?
Rebuild or replace the faulty purge exhaust valve. Use manual
override to check.
• IS THE OUTLET VALVE FAULTY?
Check the outlet shuttle valve.
CAUTION
THE DRYER CONTROL CIRCUIT IS DUAL VOLTAGE RATED.
NEVER SET THE BOARD TO A VOLTAGE OTHER THAN THE
VOLTAGE RATING OF THE DRYER LISTED ON THE DRYER
DATA TAG. SETTING THE BOARD INCORRECTLY WILL CAUSE
DAMAGE TO THE INLET AND PURGE VALVES AND POSSIBLE
PERSONAL INJURY OR FIRE.
9.6 WIRING DIAGRAMS