Gardner Denver AUTO SENTRY EAU99P Operating And Service Manual page 58

Oil impinging on the inside of the separator element drains directly back into the oil reservoir by gravity.
Oil collected outside the element is returned through tubing to the compressor cylinder.
Oil carryover through the service lines may be caused by a faulty oil separator, faulty minimum
pressure valve, over-filling of the oil reservoir, oil that foams, oil return line malfunction or water
condensate in the oil. If oil carryover occurs, inspect the separator only after it is determined that the oil
level is not too high, the oil is not foaming excessively, the oil return line from the separator housing to the
compressor cylinder is not clogged or pinched off, the check valve in the oil return line is functioning
properly, and there is not water or an oil/water emulsion in the oil.
Oil carryover malfunctions of the oil separator are usually due to using elements too long, heavy dirt or
varnish deposits caused by inadequate air filter service, use of improper oil or using oil too long for
existing conditions. A ruptured or collapsed separator element is usually due to heavy dirt or varnish
buildup in the filtering material. Excessive tilt angle of the unit will also hamper separation and cause oil
carryover.
Oil separator element life cannot be predicted; it will vary greatly depending on the conditions of
operation, the quality of the oil used and the maintenance of the oil and air filters. The condition of the
separator can be determined by pressure differential gauging or by inspection.
Pressure Differential Gauging - The "CHANGE SEPARATOR" advisory will flash when the pressure
differential across the oil separator reaches approximately 8 psid (.55 bar). Replace the oil separator
element at this time. If ignored, the unit will shut down and the advisory will illuminate steadily when the
pressure differential reaches 15 psid (1 bar).
Using an oil separator element at excessive pressure differential can cause
damage to equipment. Replace the separator when the "Change Separator"
advisory appears.
A sudden drop of zero pressure differential or sudden heavy oil carryover may
indicate a ruptured element.
Air/oil under pressure will cause severe personal injury or death. Shut down
compressor, relieve system of all pressure, disconnect, lockout and tagout
power supply to the starter before removing valves, caps, plugs, fittings, bolts
and filters.
Inspection - After removal of separator element, shine a light inside the element to reveal areas of heavy
dirt or varnish deposits or breaks (ruptures) in the element media.
NOTICE
13-10-615 Page 57