DeVilbiss DeVO/MC44-90 Service Manual page 14

SECTION 6
TROUBLESHOOTING GUIDE
Symptom
Possible Problems Suggested Remed
Visible | Audible | Compressor Other Oss! г ugg y
Alarm Alarm On or Off Symptoms
11. ON ON ON Fluctuating | System pressure below 9 PSI (62
or no flow KPa) due to:
Leak in system Check all hoses and fittings
Defective compressor Replace compressor
Four-way valve not fully shifted | Clean or replace four-way valve
12. OFF ON OFF Fan Blown fuse on MC board Replace fuse
operating Defective MC board Replace MC board
13. OFF OFF ON Visible Defective bulb Replace bulb
alarm panel | Defective MC board Replace MC board
does not
illuminate
when unit
is turned on
14. OFF OFF ON Low pilot Leak in pilot pressure system Check all pilot pressure hoses and
pressure fittings
Defective check valve in pilot Replace manifold base
accumulator
Defective compressor Replace compressor
Defective reed valve in Replace reed valve
compressor
15. ON ON OFF Fan Four-way valve failed to shift Refer to Section 7, Service
operating, | property Instructions, on How to Trouble-
short and shoot Four-Way Valve
no cycle Contaminated sieve beds Refer to Section 7, Service
lights on Instructions, on How to
MC board Troubleshoot Sieve Beds
itluminated ,
Severe restriction of flow due
to:
Crimped tubing Straighten tubing
Occluded humidifier Clean or replace humidifier
Flow meter turned off or set Adjust flow meter
too low
16. ON ON OFF Fan Maximum cycle time was
operating, { exceeded due to:
long cycle | teak in system Check all hoses and fittings
light on MC SY 3
board Defective reed valve Replace reed vaive
illuminated | Defective compressor Replace compressor
Four-way valve not fully shifted | Clean or replace four-way valve
17. ON ON OFF Fan Purge valve stuck in activated Refer to Section 7, Service
. operating, | position Instructions, on How to Trouble-
long cycle shoot Purge Valve
andhigh
pressure
lights on
MC board
illuminated
NOTE: Some MC board alarm lights may be designated Bed, Purge/Compressor, 4-Way, and High Pressure rather than the
designations stated in the above troubleshooting guide. See Section 5 for explanation of the various alarms.
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