Gardner Denver APEXVS7-11A, Operating And Service Manual

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13-25-603 Page 54
To check the element, heat in oil - it should be fully extended at 170
°
F (77
°
C). If the unit shuts down
due to high air discharge temperature, the cause may be that the element is stuck open to the bypass, in
which case bypass lines (Figure 5-1, page 44) will be hot to touch and lines out of mixing valve much
cooler. When flushing the oil system, remove the mixing valve and clean all parts thoroughly.
OIL RESERVOIR - The oil reservoir-separator combines multiple functions into one vessel. The lower
half is the oil reservoir, providing oil storage capacity for the system and the top portion, a primary oil
separation means. The reservoir also provides limited air storage for control and gauge actuation.
COMPRESSOR OIL SEPARATOR - The compressor oil separator located on the manifold with the
minimum pressure/check valve features a renewable spin-on type separator element and provides the
final removal of oil from the air flow.
Oil carry-over through the service lines may be caused by a faulty oil separator, overfilling 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 tube from the bottom of the separator manifold to the compressor cylinder is not
clogged or pinched off, the check valve in the oil return is functioning properly, and there is not water or
an oil/water emulsion in the oil.
Oil carry-over 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. Excessive tilt angle of the unit will also hamper separation and cause oil carry-over.
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 or by inspection.
Separator Pressure Differential - The “CHANGE SEPARATOR” message will flash when the pressure
differential across the oil separator reaches approximately 8 psi (.6 bar). Replace the oil separator
element at this time. If ignored, the unit will shut down and the display will indicate shutdown and the
change separator text advisory will display when the pressure differential reaches 15 psi (1 bar).
To measure the pressure differential, see Controller Manual 13-17-600, page 4, “Separator Pressure
Differential”. Simply subtract the downstream reading from the upstream reading.
Using an oil separator element at excessive pressure differential can cause
damage to equipment. Replace the separator when the “Change Separator”
advisory appears.